40 meters QRP is FUN!

Today saw the introduction of my newly acquired 40 meter QRP CW radio that I picked up at the Orlando Hamcation. Read on to see what I think of this radio and how the activation went.

A quick over view of the radio. The transceiver is built by a silent key (W9SR) and I purchased it from the estate. The first thing you will notice is that it has no obvious numerical display except the ten turn potentiometer in the center. This is in fact the VFO or most likely the VCO if I had to guess. I am guessing as I have not dismantled the radio and really dont want to risk breaking it since it is a working machine currently. I can guess this though as it is a resistor and a resistor will allow you to vary the voltage easily on a varactor diode creating a Voltage Controlled Oscillator.

The next thing you will notice about it is that it doesn’t have any labels for the controls. At first I was worried about this, but then the fellow who sold me the radio showed me that there was a legend card included with the radio which has two critical pieces of information on it. The first is the chart that shares the value correlation of the potentiometer with the frequency of the radio output. The next thing it shows is what all the knobs and switches are used for on this little radio.

I decided to use this radio as I had a chance to activate a park earlier than usual today so I grabbed it and headed over to US-2169 (no longer K-2169 since the POTA people had to update all the parks due to the increase in activity and such with the program.) Heading over to the park I also took the Argonaut 5 kit as it has some keying gear in it I wanted to use. This turned out to be a good call as I could not get the SWR to pull down on the antenna today and I ended up adding the tuner that is also in this kit. This allowed me to add some inductance and get the antenna system to a nominal 50 ohm impedance match to the transceiver output as well as pull it to the center of the smith chart for an almost purely resistive load as well. The nanoVNA is invaluable for seeing things like this and it is why I like having it in the field.

Once at the park, I went to my usual spot at the frisbee golf course parking lot and proceeded to set up the system.

As you can see from the photo, it was really crowded today and I had trouble getting around all the people to setup my antenna system… lol. Only one park ranger and one truck passed through the lot during my whole activation, I was a little surprised by this as the weather was nice and there was a bunch of people down at the canyon, so I figured there would be a bunch playing frisbee golf too, but there wasn’t.

I have had trouble with my 40 meter hamstick the whole time I have owned it. This problem comes in the form of high SWR and I can only surmise it to be because there is not enough counter poise. I put out what I though to be enough radials and checked it and found the SWR to be 2.5:1 which is outside my personal limit of 2:1 so I added another radial from my kit that is usually for another band and checked it and it was a little better, but not great…maybe 2.1:1 or something like that.

So then I thought I would do something out of the ordinary and took my 17 meter radial set (it is one wire but it has a tap in the center with a STA-KON connector to attach it to my antenna mount). This in itself is not unusual, but the way I deployed it was. I figured I would make a single LONG radial out of it instead and see what would happen. Wouldn’t you know it, it helped ALOT!

You are seeing that right, it has a clove hitch tying it to the tree branch. Maybe that helped a little, I don’t know at this point. But I decided at this point to do some experimenting where I remembered in the past something about curtain dipoles and how you could drop a line down from the horizontal and it would change the antenna. I had some little gator clip leads in my nanoVNA kit so I grabbed one of these and clipped it to the STA-KON in the middle of the line and it made a difference too! Nothing extraordinary, but it did help so I left it. Checking the nanoVNA on the smith chart showed I had a good 50 ohm impedance to the antenna but the system was capacitive so I added the tuner so I could balance this out and get a clean load presented to the radio as I don’t want to burn this little guy up on the first outing. I ended up with a total of 5 radials put out to get the antenna and radio happy today and it looked ODD to say the least. I normally will run one or two at the most, so this looked like a spider web… lol.

I had intended to setup on the bed cover today as the weather rwas pretty nice to start with, but by the time I got to the park the wind had picked up to the point it was out of the question to try to hear CW with the radio fighting wind noise too. Because of this I setup inside the truck again and this made it easier too as I could just plug into the truck and go. So the station look like what you see below today. The N3ZN key and the Hamgadgets keyer into the W9SR 40 meter monoband CW transceiver and out of it into my little MFJ antenna tuner I keep with my Ten Tec Argonaut 5 transceiver kit.

Now, something about this little radio that is cool and most new comers to the CW corner of ham radio wont know about. This radio has relay keying. And the relay is kinda loud. It is almost comical with today’s diode switched radios that are silent and FAST. This little radio is far from a full QSK machine, but it works well none the less. I only missed a letter a couple of times and had to get a repeat to confirm it. Not bad for a radio that is probably built in the 1970s if I had to guess.

Another thing I have noticed about me lately is that I am drawn to this kind of radio more than the big box machines. I have owned some impressive radios in my day to include a Kenwood TS-950 SD, Ten Ten Omni 6+, as well as a Ten Tec Omni 7 and anybody who knows CW rigs, will know that these are all stellar CW machines of the highest order. These radios work so well that to work stations becomes almost no challenge at all. I have easily worked a metric ton of ops over the years on these radios and have loved doing it, but in the end, QRP really brings a challenge to the table that these machines cant. I know I could simply turn down the power of the bigger rig and sometimes I do, but these don’t travel well and besides it is just fun to use the tiny little machines.

Here are a few more photos of note about this radio before i I close out the showcase. It came in this ballistic nylon rigid pouch that holds it perfectly. Also I changed the ancient Molex connector over to power poles as I could not find a molex to fit it and it even how a 9 volt socket on the back that I am guessing is for some sort of accessory that is no longer needed… maybe a keyer like the Ten Tec keyers or something like that possibly? Who knows, but it is a great little radio.

As for the activation itself, I never have a bad outing, either it is good or better. Today was a good day. Any day I can make contacts is a good day to me. I made 13 contacts kind late in the day for 40 meters to be honest and to also only be using 3 1/2 watts too also made it a lot more sporty. There was a good bit of band noise today so most signals were weaker than usual, the radio did well though in that I could pick out even the weakest signals and was able to work them. I was impressed to say the least. I will be using this radio more if for no other reason than nostalgia. I love it and if you are into CW, you probably would too.

Thanks for following along today and I hope this blog post inspries you to get out and setup a radio. Until next week, 72 and GUD DX

WK4DS

I have a Penntek TR-35 QRP radio and it keeps growing...

So in this installment of how do you make a tiny, compact QRP radio MUCH bigger, I set out to add an S meter to the system! Now were talking!… or maybe more accurately were using CW … since it is a CW only radio. Anyway, I have been wanting an S meter for this little radio for a long time and then when the ham who invented this radio came out with the next generation (TR-45L) it had an S meter!

Pictured above is the new S meter and beside it is the power pack/speaker assembly, and in front of that is the Penntek TR-35 radio.

Now to be fair, I do have this radio kitted so that I can travel with it very efficiently. I have a kit that has everything I need, but nothing in the way of “frills” and this kit works great. It is small enough to pack in my carry-on bag and even has a power pack too. (Not the one pictured in the blog post but a smaller AA battery tray that holds 10 batteries.)

When I set out to add the S meter to the kit, I started looking for something small that I might could build directly into the radio housing. When I looked into how the radio is actually built though, this turned out to be less than ideal. You see the radio is one circuit board and it is connected to the front panel with ALL of those switches and knobs! Who wants to do all that work for a simple S meter install??? Well, as it turns out I would be that guy. The build to add the S meter as a stand alone part of my little kit was a lot more work than I thought it would be and then there was the trouble shooting and such… lol. Such is life and I now have a really cool, vintage S meter for my tiny station that I am putting together.

The S meter project I chose to build is brilliant to be quite honest. I am not sure who designed it first but I found the schematic on SeekIC.com and proceeded to build it based on this print, substituting parts as I needed due to what I had at hand. Since I did this, it took some experimenting to get the meter to read like I wanted as the final amplifier stage needed the gain adjusted and since I didn’t have a pot big enough, I had to swap resistors till it worked… but it worked. Sadly, I didn’t document the build at all, nor did I bother to even take photos of the internals for some reason, but suffice it to say that I am happy with the result.

Below is my heavily noted printout of the circuit from SeekIC.com. I initially built it without thinking about what was happening and it worked very poorly. This is my fault as I should have looked at the circuit more closely and realized what was going on and that I was misreading things in several places. The three resistors that have the arrows now have the decimal drawn in them. When I first printed the schematic so I could take it to the shop to build it, the decimal points didn’t show up and this meant I thought these resistors were 10 times larger values that what was supposed to be in these locations. This made for some really strange wave forms and the output only going up to .2mA on the meter with VERY strong signals on the radio… I knew something had to be wrong so I started looking at the circuit and figured I had some trouble from my substitution of the two transistors so I looked there first. That was when I noticed the voltage divider for the base of the 2N2222 (this is what I used instead of the 2N4401) was way off for a simple emitter follower amplifier. Then I really looked at the print and realized the number spacing was different on some of the resistors. Like the 15K and the “16K” which after looking more closely was actually a 1.5K… Then I went around the print and found two more like this realizing that I had this thing setup to fail right out of the chute. Back to the shop, modify the resisitor values in these locations and try it again.

That fixed the low output part, in fact, now I had a lot of output, ALOT! So I once again looked at the amplifier stage and decided to lower the gain on this amplifier from 12 down to 2.18 and see what happens. This worked, but I did overshoot the target a little so I went back and changed it to a gain of 4.3 by using a 560 ohm resistor on the emitter of the 2N2222. This seems about perfect for this little setup now with really strong signals giving full scale deflection but most running in the middle of the scale.

Also of note is that this is a vintage Westinghouse panel meter that reads up to 1mA… So this meter doesn’t load the circuit hardly at all. That was the main reason I chose it. Enough with the new S meter project though, let’s go to a park and put it on the air!

Today I went to Cloudland Canyon (K-2169) and setup by the canyon at my favorite table when the weather is nice. Then I strung up my Reliance Antenna 40m EFHW and connected it to my radio with a piece of ABR Industries coax. Before hoping on the air though, I put another of my recent projects to use, the QRP Guys SWR/Wattmeter kit. I built out the small kit for it with a water tight storage box, a small BNC coax jumper and the instructions should I need them for some reason. It runs on a simple coin cell and works like a charm. It is a great kit if you are looking for something that will handle up to 10 watts like I was.

This thing is a breeze to put together, even the little toroid transformer was pretty easy to build actually. So don’t let “winding a toroid” hold you back, it isn’t that tough to do and the reward is totally worth it.

I checked the antenna and it had less than 1.5:1 SWR on 40, 20 AND 17 meters! I was stoked to see 17 meters was also good to go. This must be something to do with the 20 meter bandwidth, I should have taken the nanoVNA with me to the table (it was in the truck) but I didn’t want to spend a bunch of time on it. I wanted to get on the air and make some contacts!

I have really come to love these cable built by ABR Industries out of Texas. They make all sorts of cabling, but for me, these with the common mode choke built into the cable is a god send. It allows me to simply put up the antenna without worry of RF getting back into the radio and causing me problems from my… less than perfect… antenna installations. When activating POTA parks there is not always a perfect place to install an antenna so you end up with all sorts of stuff on the air and it is possible to have poorly matched impedances on your antennas. The ferrite beads help keep this problem to a minimum.

This little antenna is actually quite long. Approximately 65’ (give or take as I don’t remember right off) and I strung it up into the tree in the photo below. I am pointing out the location of the end where it went to the tree from where I threw my line. It also started at the “radio end” about 15’ off the ground as I strung it over a tree limb at the table to get it off the ground. This puts the whole antenna elevated above the grade somewhat and I want to say it helps as you can see by the logbook below.

60 contacts in one outing, QRP, with decent band conditions will fill your heart with joy. This was a fun afternoon and I plan to do it again soon.

72

WK4DS

Sometimes it is nice to have a slower day

I recently setup an activation at K-2169 and had no where to be for the rest of the day… This is my kind of POTA activation!

The above photo is a little misleading, there was one other car in the lot, but due to camera angle and me wanting the truck to be in the frame as well as the parking lot it is out of view. But it was essentially empty, so it was really quiet and I didnt even see a park ranger on this day, they normally ride by once or twice while I am setup and sometimes they even stop for a chat. I have been here so much that they know what I am doing and are cool with it. I contribute this to the fact that I am in a corner of the property where there is little to no activity most of the time, I don’t consume more than one parking space with my setup, I stay out of the pavilions (I have used them in the past if they were not being used and had no placard reserving them), my setup doesn’t involve me driving stakes into the ground and I do my best to keep my footprint to a minimum. Since I use CW for the most part, I don’t make very much noise either so it is minimal impact all around. At least that is my perspective and it seems that it is also the park employees perspective as well…or they could just not care about the old codger over there with the little radios…lol.

Today saw me on the 17 meter band with Morse code and it has always been an intriguing experience. The rhythmic sound of the dots and dashes echoing over the airwaves brings a sense of nostalgia for a bygone era while honing my skills in communication and technology. Despite the advancements in digital modes, Morse code offers a unique challenge that is both rewarding and intellectually stimulating. Operating on the 17 meter band allows for reliable long-distance communication, opening up a world of possibilities to connect with fellow enthusiasts from different corners of the globe. (Check the log and you will see what I mean by waxing nostalgic) It's fascinating to see how a simple yet effective mode like Morse code continues to thrive in the modern age of ham radio.

Below is the whole station (minus the S meter I am currently building for it) for the TR-35 HF radio. I have built the “black box” of options to help complete out the radio, the box has a battery pack in it as well as a speaker for the radio since it has no speaker of it’s own and I have added a push button to activate the voltmeter so it doesn’t run constantly and drain said battery. There is also a power port on the front now to allow the connection of two accessories as well. (This is for future expansion of the kit to include one more item that I wished this radio had built into it, an S meter)…

I created the box with the cabling to connect it to the Penntek TR-35 radio and it makes a station out of it basically. Just add your favorite CW key and you are off to the races.

I really like the layout of this radio, if I could alter the design at all, it would be to add two pushbuttons to send the CW memories with, but that is nitpicking to be honest. One other thing is that I like to have an S meter for some reason, it is fine to operate without it, but I just like having it for some reason… The system works well as it is and once you use it for literally a couple of minutes, it is easy to send the memories. If you are into small CW radios, this is one to have in my opinion…

Another thing I like about this radio is the fact that all the controls are on the surface that you need when operating. I like that it has the four knobs at the bottom and i usually use all four of them in an activation! Come to think of it, I usually use EVERY control on the radio on every outing… Everything you need and nothing you don’t…except for that S meter… HaHa. Another thing I like about this radio is the size. It is so small that it fits in my hand (for the most part) and is a 4 band CW transceiver! Even though it doesn’t have an antenna tuner, this is still a huge win for me. It sold me almost immediately when I took it to the field. That was when I realized I had found the replacement for the Elecraft K1 that I had used for so many years..

What your going to notice about today’s logbook page is that it doesn’t have very many calls in it. There is a couple of reasons for this. The first one is that the band was fading in and out pretty heavily. Just look at the time stamps on the RBN reports below and the associated the dB levels at those times, it was up and down heavily. Now I understand these stations are scattered around the country, but they are all west coast for the most part ( a feature of 17 meters is it skips over the closer states for me on my hamstick) and they show an amazing amount of variation in signal in just a few minutes of time. Once I looked at this, I realized I just needed to call and when the band would open up I would get two or three and then it would close back down, call a few minutes and get a couple more…rinse and repeat. It was still a lot of fun and I work Japan in one of the openings too!!!

Just check out that one lone DX contact from Japan! I was blown away when I heard his callsign coming into my tiny little radio. I love these kinds of days just as much as the faster paced, high QSO count days. It is just fun to setup a radio and make contact with distant stations whether in my own country or half way around the world.

Thank you for following along on my little journey to a local park, I hope it inspires you to get on the air and make contact with someone out there.

72 WK4Ds

Broke out the Penntek TR-35 for a change.

When you dont use a radio for a while it is almost like having a new radio…

This radio has quickly became on of my all time favorite radios. This tiny radio has everything you could ask for in a CW machine…EXCEPT for an internal antenna tuner…but I digress. In the past I have had the Elecraft K1 (a couple of times actually) which does have a tuner (both of mine had the tuner) but it was not as intuitive to use. That is why I sold it and got this one instead. It is a better radio in my opinion… Even missing the antenna tuner, I prefer this little radio to the K1, now this comes with some needed caveats as it is not really fair to compare these two radios directly. You see the K1 was design around 20 years ago and the TR-35 my more recently with much more modern technology and features. The stability of the TR-35 is uncanny compared to the K1 which would drift a little till it warmed up. Still the K1 was a wonderful machine for my needs and I used it to activate a POTA park on the island of Hawaii last year, so it is plenty capable.

Due to the weather improving I have moved the “shack” outside and setup on the bed cover to get some sun and fresh air, plus it is easier to work since I can spread out the gear somewhat.

I like these hamstick antennas so much that I am thinking about making a tripod mount for them so that I can setup at a nearby picnic table and use them with an elevated counterpoise concept… I could even get them higher above the grade this way too, possibly improving performance a little.

So this is the whole station today, the hamstick on 17 meters with a 15’ coax to the common mode choke. I put it on the nanoVNA and the resonant point was high, and I think it is from the fact that the 17 meter counterpoise wire have some broken off of them which makes them too short for a tuned circuit. But nonetheless the SWR measurement was plenty good enough to use, so I got on the air in short order. To try to compensate for this, I added the 20 meter radial that works so well for me now in the past on a bunch of bands. (I should probably measure this wire and make a new since it is getting frazzled) but it didn’t help very much today. I left it anyway as it did seem to help a little…

The operating position today… I really like using the bed cover for the operation position as it affords me the most user space I could possible imagine as well as it is simple. I have activated with this battery 3 or 4 times at this point and it is still over 13 volts!

The key for today is the Gemini travel key. This has turned out to be a wonderful little key and I am so happy to have bought it. It works so well.

As you can see from the log, I had a great day on 17 meters and even landed me a DX station! Jan was in the Netherlands when I started hearing his callsign! It was awesome that he could hear me too!!! There was some fading of course, but he could hear me! I made a good bit of notes about the activation in the log today where you can see things happening like when I lost a QSO outright to some one tuning up on top of me…for a long time… There is another note about the time when someone had a messed up car ignition that created some broad band noise and I couldn’t hear anything for a few minutes till they left.

Quickie CW Activation

Let’s goto Cloudland for a break from troubleshooting a radio. I have been working on this Ten Tec 6 meter FM machine for a week or two at this point and finally redrew the oscillator circuit so I could more easily understand the point of all those varactor diodes…

After studying this for a while I decided to get on the air with a different radio and have some fun with CW. I didn’t have a lot of time so I decided to goto the Sittons Gulch parking area of Cloudland Canyon State Park (US-2169) and setup inside the truck. The parking area was packed on a Friday morning and I almost didn’t get to setup here!!! So much so that the only available space was next to the entrance on the shoulder of the road. You can see how close I was to the gate in the photo below.

Here is a special trick I figured out too. The one radial I cut for 20 meters and then subsequently was broken and twisted back together…(making it short for a resonant antenna on something just higher than 20 meters…). This poor radial sees so much use, I really need to make a new radial wire that is this length but without the broken spot. Another thing is that it also works with my 17 meter antenna too. So one radial works on two antennae!!! Sweet!!!

Today saw me using the Penntek TR-35 QRP CW transceiver and none of the extra widgets I have been using. Headphones are needed since it has no speaker of any kind. Another quirk with this radio is that it is wired from the factory for a mono headphone connection (this is user adjustable by dismantling the radio and changing the connector wiring physically) so I need an adapter to be able to hear the audio in both ears. For DC voltage requirements, I simply plugged into the truck power cable I recently installed and I was off to the races!

If you look at the log sheet, you will notice I started 11 minutes before I made my first contact. This is because I setup on 17 meters to start with and called CQ for ten minutes with zero answers. I finally learned my lesson and moved down to 20 meters where all the hams were located. Things immediately improved and I made quite a few contacts once I made the move.

I hope you have enjoyed this little excursion to my local park and seeing what I do when time is tight and also space is limited. Until next time, get out and get on the air.

72

WK4DS - David

My hamfest "radio" adventure

Roger (KG4WBI) and I have basically been going to the Dalton GA hamfest for 2 decades at this point and this year was incredible as far as attendance and the sheer volume of dealers in the “boneyard”.

So as per our usual modus operandi, we decide to see how many Ten Tec radios are available and this trip we also have some other items we are in search of as well.

I personally was looking for the following:

• A high power dummy load

• A low pass filter

• A ten meter radio that has the CW mode

• A oscilloscope that works up to 150mhz

Of all these items, I found the first three! Score!!!

This blog post covers my ten meter “radio” part of the adventure.I found a President HR2600 10 meter radio for sale that worked perfectly and bought it for really reasonable money. The below photo is of the finished project.

The first thing I need to do is turn down the output power to 1 watt or maybe 2 as this radio is going to be a 10 meter beacon on 28.221mhz. So I search online and find out the control to adjust the output power in CW for this radio and then I open the radio to make the adjustment…

Once open, I am greeted with a cooked lowpass filter on the output. Seems one of the capacitors failed, caught fire and in the process, scorched the circuit board as well as burning the enamel off of two inductors… now what to do?

Simple, rebuild the filter section.

Another rudimentary search on google turned up a schematic of this radio. The three parts shown are what needed replacing in the filter but since the board what charred, I opted to build a separate filter module on perf-board and wire it down to the edges where the old parts connected. This way I could cut out all the carbon so it wouldn’t leak current.

It literally burned a hole in the circuit board! The above photo shows how bad it was once I had pulled all the components from the board in the area of the damage. That carbon is a problem too as carbon is conductive so if you dont remove the carbon or remove enough parts that it isnt in play then it will cause lots of problems. In the below photo you can see where I cut out the burnt board so it would not conduct. The ground trace broke due to this damage so I simply added a jumper wire across this area to tie it back together. I only did this in case there was a need for ampacity since the ground plane went all around this part of the board. This actually worked so now to get a working lowpass filter.

In the above photo I have marked all the spots where connections are required for the various detectors to work properly as well as the input and the output to the filter section. I ended up not connecting the detectors though since it is not receiving at all and is only transmitting a beacon signal on CW. I checked and it worked fine without these two connections so I simply left them out. Someone will find this radio in the future and think they have scored a treasure until half the detectors don’t function for some reason…lol.

Below shows a coil that had the enamel burned off of it that was sitting next to the capacitor…This part of the radio was technically functioning too (well, passing the RF at the least), since this part was simply a low pass filter after the final transistor, when it burned it simply shorted through and just kept transmitting, albeit without the filtering it was supposed to have, but it was functioning…

Once I had decided to replace the filter, I started simply remaking the bad parts from scratch and using existing parts that were good, trying to emulate the original design. This is where I ran into a problem. In my desire to simply repair it like I did, I ended up creating a lower frequency null that was completely shutting out the 10 meter band… It was a wide enough null that I couldn’t bend the coils and fix it either… (With coils this small, you can shift the null around a little by spreading the coils out on the inductors, but this was not enough to get it to work for me.) So I simply opted for what I should have done to start with, make a filter from scratch and tune it out of the radio with the nanoVNA before installing it…

Above is my attempt at replicating the old parts, I measured the core diameter and it was real close to 1/4” so I simply made new coils based on this and hoped for the best. (The lighter colored inductor on the left is original from the radio, I reused it since it wasn’t damaged.) To test my theory, I simply soldered a wire across the the input and output terminals of where the filter would go (see below photo), powered the unit on and it worked fine (the transmitter was still working as it should). This is what told me the tune on the filter was off frequency. When I put the nanoVNA on the filter it had a DEEEEEEP null right at 28mhz all the way down to 24mhz and up to 33mhz! Seems my replacement parts and their new configuration had lowered the low end of the filter to the point that I was choking off my own signal. Haha…

So here is the filter I scratch built. Side note here, the capacitors in my filter are all high voltage capacitors as the output voltage of the RF signal can be very high at times. It can easily exceed 100volts in some circumstances so I chose capacitors that were at a minimum of 500 volt rated and some are even more. Better safe than sorry in this regard. It has larger inductors which give me more room to adjust them. I used an online calculator to figure the beginning values. This worked great because I had a good starting point to work from. I then connected it to my nanoVNA and checked the loss on the S21 input to see the filters shape. Air core inductors are a funny thing, they generate a nonlinear pattern of suppression that has deep nulls and at some points almost no effect on signal. The photo above shows where I adjusted one coil a little to get the null to land on the 6 meter band and also this is where this 2nd order harmonic would also appear, if there was one (knowing the quality of the factory low pass filter, it probably has a harmonic…lol). This would suppress any harmonics that might show up and also it has decent suppression across the region as well. You can see in the photo below that I added some capacitors to the bottom as well to help with the cutoff and to improve performance of the filter overall.

I ran it through the nanoVNA to tune it so it would let me run the beacon. It was losing about 3.5dB of signal at 28.221mhz but that isn’t a problem for me since I only want 1 watt forward power anyway. I simply connected the radio to a dummy load through a good wattmeter and tuned the pot inside the radio till I had 1 watt on the wattmeter. That 2nd deep null is at the first harmonic which is the 6meter band so it is working like it should. The original filter worked about as good as this one from what the math says. Air core inductors are not great compared to toroidal inductors but they do work. The first null appeared when I added one of the capacitors on the bottom, I will take what ever I can get and this added some suppression to the filter so I left it. The calculator showed the starting point of my filter with the image below captured from the online calculator. The calculator I used took the size of the coil and the number of turns and the over all length into account to come up with these numbers.

I ended up changing the first cap to 33pF by adding another 100pF in series with the other two and I also added a 33pF across the center coil (as this was what was on the original coil and the VNA showed an improvement in filtering when I soldered it on so I left it), I am pretty sure this is where the second null showed up at and also generally improved the whole filter.

So all in all, this was actually a fun little project and I learned alot about filter construction and tuning at the same time. I have said it before and I will say it again, if you don’t have a nanoVNA, get one for this sort of stuff. It works really well and it is super cost effective compared to professional gear that does the same job.

Little Manatee River State Park K-1898

I had some time today and wanted to get out of the city here in Tampa so I went to Little Manatee River State Park and setup a quick little activation on 15 meters.

This park is really nice and well cared for. It has many hiking trails as well as a creek on one side that you can canoe in…just dont pet the alligators and you will be fine there, but they do have an equestrian area as well. Plenty to do if you want to do something other than park activations for some reason…lol

Today saw me setup on the bed cover agian as it was nice out and I was mostly in the shade so I knew I wouldnt get too hot. I ran CW only as I didn’t feel like messing with the sBitx V3 to work FT8 as I really only had about 30 minutes of operating time and for me, the FT8 contacts come in a little slower than the CW contacts. I did choose 15 meters though which was a little bit of a gamble, but it worked out once I got on the air and tuned around the band a little and found it was active, I rested a little easier.

I ran the Ten Tec Argonaut 5 transceiver today with the N3ZN key and Hamgadgets memory keyer. This radio is a joy to use for CW and I really enjoy using it for park activations. It has about 20 watts full output, but today I was only running 15 watts as I normally don’t push the old transistors as hard as when they are new… probably don’t matter, but in my mind it makes sense. When I am operating, I use 3 things, well 4 if you count the AF gain (volume). I use the multi-function knob to control the BW (band width of the filter) and the RIT control. The same knob does both jobs, you just hit which ever button you need first then set that function to what you want. The display is currently showing the BW setting of 600 Hz. I will open it up if the band is quiet, but this thing is pretty selective and will allow me to go down to 250 or 300 Hz if I need it and works really well.

Today also saw the use of zero radials. I wanted to see what the SWR would be without anything since these antennae are designed to be used without a counterpoise and just work off the coax shield and car body. I was pleasantly surprised when the nanoVNA showed 1.3 to 1 right out of the chute! Seems my antenna for the band is tuned a little low like this. If I add the 20 meter radials it balances better and move the frequency up closer to where I operate and gets that super deep null right on me.

I did experiment a little with how I laid out the coax to see what it would do and the result was minimal to say anything. I think I changed the reading by .01 SWR from start to finish. Totally not worth the extra effort to optimize the coax… The photo below shows me pointing at the best setup I found and the screen of the VNA showing my target frequency on a 4Mhz slice of spectrum.

I had problems with RF in my keyline. I am guessing due to the proximity of my key and keyer to the antenna. With electronic keying, rf can trigger the keying circuit adding unwanted dots and dashes to your code. I solved this by adding rf chokes to literally everything. If you will notice they are on the key cable as well as the keyer to radio cable and I still have that huge one on the coax as well. I have not added them to the power cables yet but might to see if it will help.

At the end of the day, all POTA is good POTA and I had a wonderful time working a ton of stations. The Ten Tec Argonaut 5 is a great little radio and I count my blessing for being able to land one for reasonable money. If you are a CW guy, then I suggest you try some of the Ten Tec radios as they are simply sublime machines for this mody. I quickly became an addict of their radios and will continue to be for many years to come. Thanks and I hope you get on the air and have some fun soon!

73 - WK4DS

Back in Florida and at a park!!!

Since I am down in Florida for a little while and I am finally going to Hamcation, I thought I would do some POTA as well. Today I had a few hours to spare so I went out to K-1829

This is a new “to me” park so I was a little excited to see what it would be like. When I first looked it up, I noticed it has a check in station at the entrance of the park and a campground and lots of trails. This park is quite large too so it was going to be interesting to see where I could find a spot to setup. With gated entrances and check in stations, these parks usually charge a fee to enter them. Not so here, well sort of… You see, as I was getting near the entrance, I noticed this equestrian parking area and when I checked the map, it was fully within the park boundries. I checked the board for parking rules and there were no rules like payment needed or any specific place or anything like that, so I pulled in here as it was right off the main road.

Once I found a spot under a shade tree, I started thinking about what band to start on. I settled on the highest band I have a hamstick for…15 meters.

This is where I learned something today about the setup that I didn’t know before. The coax is what makes this antenna resonant on 15 meters. Yep ,I put the common mode choke at the base of the antenna and the SWR was 1.4 to 1. Move the choke to the other end of the coax and it was 1.021 to 1! I guess I tuned it with this piece of coax in this position or something as I had deployed the 20 meter radials and then the 30 meter radials to help and wiht just the 20 meter radials, the SWR was 1.65 to 1. This is technically usable, but I prefer it to be a better match to the transmitter output impedance, so I kept experimenting till I figured it out.

Below shows the first radio I used today. The TenTec Argonaut 5 is a wonderful little radio. Since I like CW for my activations, this is a great radio for me. I don’t even have a hand mic in the kit (I should change that to be honest)… Today saw me also as the MFJ 941C antenna tuner as well. I don’t need this tuner with my hamsticks as they are resonant antennas, but I wanted to play around with the SWR meter a little and this also allows me to keep an eye on the antenna system too as I can see the SWR changing in real time this was way. The Argonaut 5 has no built in SWR meter so this fixes that shortcoming for me.

Today also saw the re-emergence of my N3ZN CW key as will. It is a wonderful little key and works like a dream. I run this key through a Ham Gadgets memory keyer for my POTA ops. I store all four memory locations with useful data to streamline my activations. I also have two different cables to connect it to the radio with as well. One goes into the back where the traditional key input goes and the other is a hybrid cable that connects to the mic jack on the front of the radio. You can see it in the above photo with the noise suppression toroid inline. I have been so stuck on the sbitx radio lately that I had forgotten how fun it was to use this little radio.

After I worked a bunch of CW contacts, I moved up to the Ft8 part of the band and changed radios so I could work some FT8 contacts while I wrote out my log in HAMRS. Since FT8 is relatively hands off, I can get my log file for the POTA site done while getting some contacts on FT8 as well. I was able to get 19 digital contacts in the log today like this before I ran out of time. Not too bad for a guy who doesn’t know much about digital modes.

Here is a hint about the sbitx. Don’t forget to update the grid in your settings file before you start or you will be handing out the wrong grid… That one is free. Lol.

The one thing about Florida parks that is very different from back home is the presence of aligators in the water. Back home, it is nothing to goto the river with your friends in the summer and go swimming, but here that is a risky proposition. The park warns of it and I am pretty sure that is what I saw out in the water before I left for the day as well. It is hard to tell in this photo but there is a tiny object right in the middle of frame below that was moving in odd patterns around in the middle of the water, could have been a log, but my mind wants to say it was a gator…lol.

Here is another subject I learned about today you might say. I wanted to see how much difference it would make to move the common mode choke from one end of the coax to the other on my 15 meter hamstick as I am pretty sure I tuned it with the choke at the transceiver end of the line. Well, it made a huge difference to be honest about it.

The ground plane makes a huge difference if you plan to run resonant antennas, just keep that in mind while you are tuning up your system. EVERY device in the line will factor into the system impedance and is important. Dont forget that.

The log today shows of many Canadians as well as a Belgian too! I was really stoked to get them into the log as well as Utah and Idaho, those are all pretty long trips for 15 watts and a hamstick, but they made the trip! I am constantly amazed at what you can do with these little diminutive antennas to be honest about it. Just goes to show that about anything that will tune up (with or without a tuner) will radiate a signal and can make contacts. You hear about people having to load their gutters because of covenants restricting antennas and I dont doubt that they make a ton of contacts with them.

All in all, I see that there was no need to get the other antennas out at all. There was plenty going on up on the 15 meter band so I never bothered to move off the band. It was a great time and I hope to replicate it again soon.

Until then 73,

WK4DS

15 meters was on FIRE TODAY!

I don’t normally chase DX…

But today it wasn’t really an option to do anything else at one point. I had been wanting to use FT8 on the higher bands but had not had much of an opportunity lately. I got a day off and the bands were on fire so I figured it was as good a time as any to setup a POTA operation and see what I could do. As you can see in the above photo, it went splendidly well.

This was the operation position today. The cab of the truck has become a familiar place recently what with the temps being so low. (I really should get the armrest recovered at some point.) The difference was today is that I was just lazy and didn’t want to setup away from the truck. So I used the hamstick antennas and just sat in the truck to operate. It really is a convenient location to setup a POTA activation to be honest. Today also saw the use of my new Christmas present, a small writing table that hangs on the steering wheel. This is handy once you get it setup properly. I was able to log while operating and even was able to do some call sign searches on QRZ.com at the same time.

Above shows another milestone as well, I finally worked my friend KV9L on FT8! He is the person that got me into digital modes to start with and it took me months to finally get on the bands at the same time as him and then find a band that would support our QSO, turned out to be 30 meters today was that band. I worked a bunch of 20 meters FT8 before I moved and tried to find him on 30 meters though, but the antenna I was using has the wrong take off angle to be able to hear him on 20, so that is why we moved to 30. Once on 30 meters, and after our SKED (of sorts) I worked a few more ops there before getting my “chip in the big game” and moving up to 15 meters. Boy did it pay off too! My very first contact on 15 meters was Russia! Then it was DX station after DX station for the next hour, with one lone US operator hopping in as well. I would have to reposition my transmit frequency from time to time due to band crowding and such but the QSOs were steady. People will transmit right on top of you and if you don’t have any power…like me… you move somewhere else. Well with that kind of luck, I figured I would hop on CW and work a ton of CW contacts too…

Didn’t happen like that at all. I worked two ops on 15 meters CW, there just wasn’t anyone on the band and it was fading pretty hard for CW to hold up. I did get one DX station and Paul (KJ7DT) from Idaho so the mileage was still working great, just wasn’t many ops down there at this point. One of the reasons that I think the band held up so well for me today was the nanoVNA. As you can see below, the SWR plot shows that I had the radials positioned perfectly for a broad-banded usage potential on 15 meters, I thought for a minute about hoping on SSB and see what I could do, but really wanted those 20 meter contacts more… lol. With things this good I had to get on FT8 a while and this is where I got all that DX. When the conditions are right, you just get in the groove and have a wonderful time.

As you can see above, I was using the sBitx V3 with the native FT8 software today. It is functional and efficient, but it is the only one I know how to use at this time. Maybe at some point I will get FT4 going too. But for right now I am happy to be making FT8 contacts on this little radio.

Once I got finished tinkering around on 15 meters CW I decided to see what I could do on 20 meters CW. I moved down, which involved an antenna change… This means getting out of the truck, going around back and switching the ham sticks out, then if I have not done it yet for the new band, I have to install the radials. Fortunately the 20 meter radials were already setup so it was just the vertical and back inside the truck to check the antenna prior to putting RF on it and then setup the radio on 14.063mhz and started calling CQ. Well it didn’t take long and the calls started coming in from all over the USA. I had wonderful propagation today to all corners of the Untied States and the logbook reflects this as well. I even worked a VE7 call that was in Arizona! Everywhere from Washington state to Mississippi was there today, it was awesome!

This QSO map says it all, The 15 meter band was a great long distance band on this day. Just look at all those pins in Europe and Russia! If you don’t normally venture far from 20 and 40 meters, I would highly suggest giving the higher bands a shot sometime, you just might be pleasantly surprised at what you find! KV9L said that 10 meters was just as good if not better!

I hope this story inspires you to get on the air and try something new.

73

A Frozen activation…

Today (Jan 20, 2024) was a nice day other than the temperature so I figured I would setup a simple POTA site at K-0716 Chickamauga Battlefield on the Tennessee side of the park. This location is called Eagles nest and is a rock quarry probably for road construction in the late 19th century or early 20th century if I had to guess.

To some people 19 degrees doesn’t sound too bad, but for a Georgia boy that is down right cold! I ran the heater as much as possible to “charge up” the cab with as much heat as I possibly could before I started. Haha.

Since I only had about an hour, I figured I would just work 20 meters to have the highest probability of success. As you can see in the photos, this was a fairly simple deployment since it only used the one antenna and a pair of tuned radials. I also ran the coax through the door jamb to keep more heat in the truck. This deployment style netted me an SWR of 1.2:1 which is really good for my uses.

Here is a photo showing the height of the antenna over the ground. I am 6’2” tall. I really think this helps with the take off angle and also allows better impedance matching by allowing the radials to angle down from the mount. At some point I need to do some experimenting with more shorter radials to see how that would work instead. Dave Casler - KE0OG on YouTube has a great video discussing counterpoise wires and it is worth watching if you are interested in this. It is embedded below…

I did a wide angle shot of the operating position today to show how simple it can be if needed. I propped the radio on the storage case and simply used the armrest for my notebook. I operated both CW as well as FT8 today and it worked fine. If you look close, that water bottle in the console is frozen solid. Lol. I did shut down the truck to get rid of some RFI it is making locally as well so heating it up first was a good idea. The band was in great shape today without any fading that I could hear or see. The below photo is of the sBitx V3 software showing the FT8 portion of the band and how it is very busy with activity.

I am still using paper logging while operating in the field even for FT8 so that I don’t lose any of the contacts I make. The sBitx has automatic logging but it does contain some bugs at the time of this writing and will miss one on occasion so to prevent this, I paper log all the contacts during the activation. This is something that I obsess over for some reason, but I do like the peace of mind knowing that I have a hard copy of the activation should something electronic fail.

All in all, I had a really nice time activating on this frigid day and hope that if I get the opportunity, to work you someday as well. Until then, have some fun out there!

Two days- Hamcation and two POTA parks!

Well, it has been two quite long days to be honest and I am tired while I type this up. BUT, it has been incredible to say the least. I have heard about Hamcation for years, but I have never actually been able to attend until now. I will also be honest and say that I was not prepared for what I found, nor did I really expect to find what I found as well.

Of course, I am leading with a photo of me and Tony N3ZN as he makes wonderful Morse code keys, one of which I have and use for my POTA activations routinely. It is always good to catch up with Tony if I have the opportunity. Shameless unsolicited plug – if you are looking for a really high-quality Morse code key, then this is a wonderful place to look, just saying.

Every organization you could imagine was represented at Hamcation. People from the ARRL as well as the Long Island CW club were there, among others such as AMSAT and the local boyscouts troops and so on.

Some notable things that caught my eye were this giant double Tarheel adjustable dipole seen above, as well as the full line up from Flex Radio as seen below. Well, this is the Maestro control head but they had everything they offer up and running so you could play with them. These are some really nice machines to be honest about it. The display is also a touch screen so that is why there really isnt a need for a ton of panel mounted buttons. I do like having buttons, but this is me hanging onto legacy machines that the bigger the radio the more features you could cram onto the front of the radio had back in the golden era allowing for easier access to the functions. The Elecraft K4 shown below is the perfect blend of touch screen controls and panel mounted buttons in my opinion.

Now for something that me and Trey started back a couple of years ago. We would search out all the Ten Tec radios to see what all was out there for sale just to see. Well, below are all the Ten Tec radios that I saw in the bone yard. Some are actually marked as parts machines. This is new for me as normally they are marked as working perfectly (whether they are or not LOL). There was one amp that was marked as a project, probably due to failed tubes that are no longer available and would need a fairly extensive modification to use different tubes. It would be worth it though as the filtering in Ten Tec gear is superb.

Anyway I was surprised that this was everything as there were ALOT of vendors setup in the bone yard. Pickings was a little thin for the brand. To be honest, the main brand I saw on the used gear tables was ICOM and then Kenwood right behind ICOM with a few Yaesu and one Elecraft K3 that I remember…

Below is the new Elecraft KH1 pocket HF transceiver. This radio is going to do two things really well. SOTA and travel radio will be revolutionized by this machine. The fact that is is so small that it is basically the size of a modern smartphone and can talk around the globe, has a built in key, battery, antenna tuner, antenna, logbook AND pen is insane! I really like the concept alot.

I did buy a radio though it was not a Ten Tec. I bought the 40 meter QRP radio shown below that was built by the late W9SR(SK). It is a 40 meter monobander and is really old. Once I get home, I will update the cable with powerpoles as I couldn’t find a molex to fit it at the whole show and then I will test it some into a dummy load to get the power and make sure the frequency is still right and then it will goto a park! His brother was selling some items and this was in that lot. I am glad to know some of the history on it and hope it works right so I dont have to spend a lot of time figuring out how it works internally. Lol.

Speaking of POTA… this is how I did Hamcation this year. Teresa and I are actually staying in Tampa for these two weeks so I drove up each day for the show. Arrived about 8 and since I am “media”, could check in and get photos and talk to vendors a little about things prior to the show opening. This is how I got most of my photos of the booths. Then right around noon or so, I would leave and head back towards Tampa and along the way, stop at a POTA site and get in an activation.

The first one I got plenty of photos and was in the shade the whole time and was outside, the second was none of that. HAHA

I love operating from the bed cover of the truck with the N3ZN key and my Ten Tec Argonaut 5 radio with my Hamgadgets Memory Keyer. This whole rig just works so well and is so fun to use.

This is the first park and was a lot of fun. I setup on 20 meters as I wasn’t sure about band conditions and such and didnt want to take too long, but as you can see in the log, that never was a problem. The little Ten Tec Argonaut 5 works like a dream, I easily secured the activation in 30 minutes and was still back home before 6PM.

The next day I did the same thing with my schedule but with a park that was closer to the Interstate exit so I had longer to operate. I only got one photo of this park and it was of these giant birds walking around in the parking area while I worked FT8. These birds are LOUD when they “sing” if you can call it that. They were maybe 15 feet from the truck when they would make the call. Did I mention that it was loud? Good grief that startled me when they did it the first time!

Since there was no shade at this location, I faced the truck away from the sun, rolled down all the windows and setup in the cab where I was out of the sun. I ran the sBitx radio today since I wanted to work some FT8 as well as CW. This worked great as I had the activation in the bag in no time but wanted to work some additional contacts for a while so I went back to FT8 and made several contacts there while I transcribed my log into HAMRS so I can put it on the POTA site.

Notice on the map just how close the pin is to the interstate in the above image. That was a really nice perk to this park, it was easy to get to and not far off my course heading back to Tampa.

The above photo is a dramatization. Lol. This photo is from a different day but it looked EXACTLY like this duri g this activation as well, I just forgot to get a photo since I was in a hurry.

I hopped on 15 meters at this park, being curious as to how it would work and boy did it! FT8 ran really strong and then CW came in for many great contacts and then I worked 8 more FT8 contacts before shutting down the station and heading home. 41 contacts total with several into Europe on FT8 which is awesome! With my time running out, I packed up the radio and headed back to Tampa for supper with Teresa. This was a great weekend for me as I was able to goto the Hamcation in Orlando AND activate two POTA parks as well! How much better can it get???

I hope you enjoyed this little AAR about my weekend at Hamcation. 73

WK4DS

How well does 17 meters work?

I see a lot of people on 20 meters, but what about 17 meters? I take the sBitx v3 to Cloudland Canyon State Park (K-2169) for a little fun on 17 meters today…

sBitx V3 running FT8 natively on 17 meters.

The WARC (World Amateur Radio Conference) bands are nestled between the typical bands and everyone knows what they are because it is on the license tests. The ones I am referring to, in case you forgot for some reason, are 30 meters, 17 meters and 12 meters.

What the license test doesn’t teach though is that each band has unique characteristics that make it fun to use…at least that is how I see it. Since each of these WARC bands are stuffed between other typical ham bands, they seem to take on the characteristics of the two bands they sit between. Take 30 meters for instance, it will act like 40 meters with NVIS propagation on my hamstick to work hams just a couple hundred miles away and then I will work the west coast on the very next contact as if it were also a 20 meter contact.

Well, the higher the bands get the further they tend to reach more distant stations for me. I don’t have giant towers that have huge Yagi antennas on them for say 40 meters so my results are more of the typical ham who might have a dipole that is technically too low to the ground for textbook operation or a vertical with a couple of radials…you get the idea.

The 17 meter band has the same characteristics as 20 meters as well as 15 meters a lot of the time. For me the higher the band, the better the DX usually. I guess it has to do with the fact that the higher the frequency, the smaller the antenna and with a smaller antenna, the lower it can be to the ground and still have proper performance. Armed with this VERY basic knowledge of antenna theory, I usually expect some cool European stations on 15, 12 and 10 with the occasional DX on 17 meters, but today the sky was alive! Well, it would fade in and out and you can see it in my logbook reports. The signals reports over the time period of the activation go from 599 both ways to dismal 529 and 229 reports within an hour. This has been the norm as of late too, a lot of my activations lately have had events that would be described as cyclic in nature. I would hear a station call and reply to them with a 599 because they were booming in and then when I turn it over to them to reply, they will be a lot weaker and then you can literally hear them fade out while you watch and then fade back in by the time they turn it back over to me. It is really odd to hear that in real time for some reason.

When I got to the spot I wanted to use for the activation, I was the only one there. So I setup in my usual spot and figured I would start on 17 meters to see how things were and if it wasn’t really happening, I could move down to 20 meters and get the activation easily there. I should have known things were going to be good when my first station of the day was VK3AWA!

Now you need to know something about me here. I thought this was a Canadian station since the call started with a “V”. I work so many Canadians that I have become accustomed to hearing the V callsigns and happily add them to the log. It wasn’t till I checked the QSO map that I realized that he was actually in Australia!!! They (it is an Australian club call) must have had a Yagi antenna pointed at me or something, along with a path opening as the signal reports were really good for a 12 watt transmitter running into a ham stick antenna on the back of a pickup truck. This contact was on FT8 and FT8 reads the signal strength in dB with the software to get the most accurate reading possible to send back. So it isn’t quite as subjective as something like CW where a lot of people (me included) will send signal reports based on how the op sounds to them and never reference a meter one time… So for my little radio to get a -8dB report from Australia had to have help from the atmosphere and probably a very good antenna on their end.

FT8 is a relatively new mode for me. I have normally not done anything other than the two original modes of CW and voice. For me to reach out into a new mode is a pretty big deal and this one works really well, which is why I like it. I am also looking to start messing around with PSK 31 some as well as possibly RTTY if I can figure out how to get the little radio to do it. I think PSK 31 will be pretty easy to master, so I will tackle it first.

The above map shows the performance you can normally expect from a band like 17 meters. Notice there is practically no contacts inside of about 600 miles other than two oddities here in Georgia? That is because of the antenna and the ability of 17 meters to have a pretty decent take off angle and also to reflect off the ionosphere easily. This garnered me a ton of contacts in the pacific northwest as well as the Atlantic north east and a scattering around the country to include Utah and southern California. Then there is the EU… I made several contacts with France and Germany today. That has been a little unusual lately for me and my system to be honest so I was stoked to see them in the log.

But this trip did something that I had not done before that I can remember… It netted 7 Canadian QSOs alone, combined with the other DX calls I technically activated today with only the DX contacts! That has to be a personal first.

I started with a DX call and finished with a DX call. How cool is that? It was a great day for radio and I really enjoyed using the sBitx with the new V3 firmware. The radio works so much better than the previous firmware and the FT8 is a breeze in the native radio setup. It you are into smaller radios and smaller companies and the idea of help from a collective of literal geniuses that willingly share their information with you, then this just might be a radio you will like. It is for me, I have had so much fun with it that it is hard to understand how I got along without it before…and the people over at HFSignals dont even know who I am…haha.

A quite soggy activation of sorts

I had a couple of hours today so I went to K-2169 to setup in the truck since it was… a little rainy.

These kinds of conditions are the exact reason I build the “trucktenna” mount for my truck. If I had not done this back last year, I would not have went to a park today and made over 40 contacts. Plain and simple. As you can see I did do some expedient temporary water proofing with some electrical tape, this will do the job for a couple of hours, but make not mistake, this stuff wont keep water out for the long term and should not be a permanent solution. It will get you by at a POTA park though.

I ran out three radials again today as I had plenty of time and wanted the SWR as low as possible since I knew I wanted to attempt FT8 for a while today once I finished my CW section of my activation. I like this location too as it is out of the way of other cars, there is no need to walk behind my truck in the spot so no worries about people getting into the radials, and I can run the radials out as far as I want without and problems at all. I also opted to run the coax through the top of the door where there is no sharp change in direction with the door seal and door jamb, this allows me to keep the window rolled up and rain out of the truck cab better.

There is something about a vintage pickup truck that is just plain cool to me… yeah, this truck is legit 18 years old at this point. Hard to believe that it is that old to be honest, sometimes…

In the above photo I have a picture of a another truck in the parking lot (the black blob on the right side of the photo) that belongs to a couple of frisbee golfers that we out playing a round when I took this photo. That is one dedicate group of people if you ask me…lol. I would not have left the house today with this kind of weather looming over head. I thought it was a funny image with the rain coming down almost sideways and their truck was a little blur across the parking lot from all the water on the windshield.

I shared the above image of the radio to show how the fan is setup and that it even works when the radio sits like this since it is in a armored shell fitted to it. The fan would cycle during the FT8 session a good bit, probably coming on toward the end of each transmission after about 3 minutes of transmitting at 25 watts of output power. It also gets the radio out of the way of the armrest so that I can log easier too. It also puts the screen at an angle that is easier to read as well as manipulate since it is also a touch screen to control the radio and I don’t use the mouse and keyboard in the field, just the touch screen.

In the below photo you can see the radio working WD5BFH for a QSO. This in itself is of no real importance to the story, but I grabbed this image to share a unique trait of the sBitx radio. That is, it will ignore some call signs and will not let me click on them to complete a QSO for any reason. The call W7PK called me several times and you can see many of them in this photo, but I could not accept his call at all. I tired numerous times to select him for a QSO and it would not do it. To test this function, I chose other calls and those worked fine. I don’t know why either is the main problem. I have some homework on this part to figure out, this is not the first time I have ran into this problem on this radio, but it is pretty infrequent. It will just chose someone for some unknown reason and not let them talk to me on this radio using FT8…

You can also see the top of the logbook page also in this photo and this is how I setup the screen when running FT8, it allows me to see the completed and logged QSOs while it is working a new one and I have time to write down the last one and put it into HAMRS for my ADIF file. This is why I like to run FT8 at the beginning (while I am getting my logbook ready in HAMRS and my spot on POTA) and the end of the activations, it allows me time to do housekeeping while I am also able to make some contacts on a different mode as well. I really like that.

I had trouble at the beginning of the activation getting connections on FT8, and that is why I hopped over to CW after only 3 contacts. Sometimes one mode doesn’t work and the other does… it is kind of the luck of the draw. As you can see the CW section showed up in great number.

All in all, it was a good time and I made over 40 contacts today, which is a good day for me. I really like it on days like today as I really couldn’t do much else today, other than work on projects in the machine shop… It was really the perfect POTA outing in my book.

Broken antennas and a quick activation at K-2169 is what ham radio is all about!

I started today’s activation at the Sitton’s Gulch parking area. This is a quick access location for me as it is only about 15 minutes from my house to this spot.

First thing I had to do before the activation though was make a new center conductor for my hamstick mount. Since I made the truck mount out of thicker flat bar stainless steel in the machine shop, it didn’t occur to me that the antenna adapter is going to be too short. Well, it was and I ended up stripping out the last 2 threads on the stud because that was all that was holding it together. Problem here was that I couldn’t reuse it like it was, enter the machine shop at this point.

Below shows the arbor press pushing out the center conductor from the mount itself. This turned out to be a fairly straight forward affair as well, which was nice.

Once out of the arbor press, I was able to examine it more closely. It is a simple part so I decided to make a new one out of bar stock. I dug around in a couple of bins and came up with some brass bar stock and set it up in the lathe and proceeded to cut out a new center stud that was the right size for my needs…

Here we have the new part coming out of the bar and all the unneeded parts (chips) flying off at high speed! Lol. I love machining brass, it is such a joy to work with compared to stainless steel or titanium… Since the stud is press fitted into the body I really had to watch a couple of the dimensions to make sure they would fit properly, but several were pretty loose and were really not critical so I was able to get this part cut out in about an hour total, which for me isn’t too bad.

The solution was to make a new stud that is .200” longer thus allowing for the thickness of my mount. I simply replicated the same measurements, other than the length of the threads, and pressed it back into the housing and now I have an antenna mount with the correct amount of threads for my particular application. I also did one other thing too, I hand fitted the threads to the coupler that screws onto it, this gives me the best possible thread fit between these two part as well as the strongest fit as well. Since I know this is the only place these two devices will ever be together I don’t think it will turn out to be a problem later should there be some need to use it with another setup.

With it repaired and installed on the riser frame, I can now get back on the air and stay warm in the truck too!

Something of note in the below photo is that I use the nanoVNA to check my antenna every time I setup now (or as often as possible as long as I have it with me and it is charged up). I have found some odd stuff a couple of times too because of it. This is how I found the broken coax center conductor a while back as well as some band Sta-kon connectors on my radials a couple of times.

I will even use it between band changes just to see what the SWR is going to be like in a certain band location now. It is a really handy little tool. I highly recommend you picking one of these up and learning a little about it at some point, they are fairly inexpensive compared to the antenna analyzers and will give you the same information plus some. It just takes a little time with YouTube and some patience…

Once the antenna was deployed, I got back in the truck and powered up the radio to see if there was anything going on and boy was there! In this photo I am working FT8 on 15meters and as you can see the band was not very active with FT8 operators (you can see it on the waterfall). No one answered me, probably because they couldn’t hear me very well compared to other ops, and after a while I decided to see if there was any CW contacts on 15. After several minutes of calling CQ, I had netted just two contacts. These two showed how good 15 meters is for distance though with both of them being a great distance away from my park. So sometimes the band just isnt there for you to make contacts even if the RBN says it is.

All that aside, I started on 20 meters as it is my goto band if I dont have a lot of time. If you have been reading my blog posts for a while, you will know this, so here I am on 20 meters and I decide to start on CW this time and see what I can find. I get my spot on the POTA site and off we go, it didnt take long to secure the activation and then some and once I had cleared the little pile up I had going I decided to hop on FT8 to see what I could do. FT8 went really well there to with me netting 14 QSOs there as well before I decided to move up to 15 meters. What I really like about FT8 is that it is pretty hands off, this allowed me to fill out me log on HAMRS and get it caught up to the most recent QSO before I finished out this mode and changed bands. That is really cool in my book.

Now that I have the wiring in the doors repaired I am able to route the antenna coax though the window the easy way as long as it isn’t raining… This is really fast and doesn’t pinch the coax like running it through the door jamb does when I operate in the rain. You really don’t know how convenient this is till you don’t have access to a feature like windows that roll down… It is almost comical how long I put off repairing the wiring in the two back doors and to be honest, it really wasnt that hard either…live and learn.

In the above screenshot you can see that there was plenty of signal but there just wasn’t many CW ops on the band. I did get one Canadian and Paul up in Idaho before going QRT though. I was happy to get at least a couple of contacts once I setup on the band. It is always interesting to see what the range of a band is when the higher bands are open. I have gotten some pretty long distance stuff with some really bad antennas on 10, 12 and 15 meters in the past. It just takes going up to those bands and looking around and the right time of day for it to work…the band has to be open too, but we all know that at this point…lol.

Today’s key was the Gemini Ham Radio travel key, This little key is great for me as it is the perfect size for my hand and I really like how it collapses into the housing for travel. When you take it apart, you see how simple the design is and that you don’t have to have this super complex device to send good code. This thing really is pretty simple and it works great.

Below shows the radial field I laid out today and this was just to give it something to work with as they are all on the same side of the truck! I used one of my tuned 20 meter radials and the set of 17 meter radials and this gave me great SWR on 15 and 20 meters. I like it when this works out… Of course, since I am using a ham stick, the truck body is part of the ground plane and the radials interact with it so the SWR will depend on where I put the radials. This is why I always attempt to put them at right angles to the mount if at all possible as this is how I tuned them initially and also allows me to adjust SWR somewhat by simply moving them around behind the truck.

This is also a first for me as my log shows almost as many FT8 contacts as CW contacts. (14) FT8 contacts and (19) CW contacts is a good day when you only have an hour and a half or so to operate. I have never been one to try to get hundreds of contacts in one outing, even though it has happened a couple of times, I am more about just getting on the air and having some fun. So at some point I hope to work you on one of my POTA trips!

73

WK4DS

Tallulah Gorge K-2202 AAR

Activating Tallulah Gorge K-2202 AAR with photos!

Today saw me leave Maggie Valley and head south as I had to be at the Atlanta airport at 6PM to pick up the girls on their return trip from Belize. Since I was going to have all day to complete a 3 1/2 hour drive, I figured I would take my time and stop at Tallulah Gorge State Park and do two things. The first was to activate the park as it is a POTA park and two was to goto the canyon and get some photos for my photography video I am making.

Well I get there and it is sprinkling rain the whole way down and it is basically raining when I park. I debate for a minute if I should activate first or do photos first and my desire to stay dry outweighed my desire for photos. So I set up the sBitx and just the 20 meter hamstick as this produces about 1.5:1 SWR which is usable and I have never had trouble securing an activation like this in the past, today would be no different in that respect although something notable did happen as a result, or so I believe it is a result of the higher than normal SWR… As you can see, all of the parking spaces, negated the ability to back into the space as the area was difficult to maneuver in, so they made all the parking spaces “pull in” at a slant angle. Since I could not back in I did not want to be spreading out a counterpoise wire risking park staff saying something. So I ran it wiht just the antenna…

To start with I wanted to do some FT8 as well as this affords me some time to do some other stuff like setup my logbook in HAMRS and get my station layout sorted and such. I like how automated it is for this reason alone. It also allows me to check things like the antenna tuner since it does those long transmit sessions as well. It didn’t take but just a few minutes to get a half dozen contacts in the log and this mode is not optimized in the v2 software. So after I spent about a half hour on FT8, I went ahead and switched over to CW to see what I could here there. Well, the band was pretty active. I had also scheduled my activation so I was confident that the RBN and the POTA networks would spot me. I did this as I had already been to two parks that didn’t have cell service and I had never been to Tallulah Gorge before therefore I didn’t want to take the chance on it not having service either. I was pleasantly surprised to find that it did, in fact, have great cell service so this part went great. Below you can see how I propped the radio against the storage case I picked up at Harbor Freight and it put it at the perfect angle to interact with the touch screen. I also saw where another ham swapped out the VFO with one off of a Kenwood and it looked great, he said it also felt great too… has me thinking about making one for mine now…haha. Also note that N3ZN key, this is what I was doing while I was also making FT8 contacts, I have been working on finding the right setup for running CW from this location and this is where I put the key today to see how well it would work. It worked ok, but I did end up moving it and there seems to be no location that makes it a solid “the key goes here” spot when I operate in the truck…

Once on CW, I work a little over 20 contacts then this is where things take a strange twist, I decide to continue sending CQ, as the system was working well, and it just shuts off abruptly.  Some simple troubleshooting found that the fuse was blown. So I scramble around and find a fuse that was slightly larger than the one that blew, put it in the system, turned it on, and it immediately blew that fuse as well, so that tells me that something is wrong with the sBitX v2 at this point. It could be the finals in the transmitter, or it could be the large power transistor in my home brew fan control circuit that could have went bad as I did not have a heat sink on it. The fan pulls such a little amount of current, only 300mA, and the transistor was rated for 6 A that I figured it would never kill it. It may not have and it could have been the higher SWR that I was seeing compared to when I normally have the SWR at almost 1.1 to 1 or better. I have heard that the transistors in this radio are on the small side of max voltage and the SWR could have pushed the voltage high enough to kill them… Spoiler alert…that is exactly what happened. Once I got home, I found that one of the finals was shorted completely, I replaced both of them and the radio sprang back to like.

Anyway, with the radio that I was using dead in the water, I decided to switch over and get out the Ten Tec Argonaut 5 radio, and finish the activation with it. Luckily, it was still in the truck from the last time I had used it before the trip. This just goes to show that you should always carry a back up. Lol. This took almost 15 minutes to sort out ultimately and I have a big skip in my logbook because of it, but I was able to get back on the air, on the same frequency as well, and finish the activation getting almost 40 contacts in the logbook before I went QRT.

Once I finished the activation it had also pretty much stopped raining as well so I got out the camera and got some photos of the gorge as well. This park is a real treat and if you have a decent cardio regimen, then taking the stairs down to the cable bridge is a treat, but be warned, the climb out is legit strenuous and is not for the non-athletic individual. You can get yourself into trouble here if you don’t heed the warning signs posted at the top of the stairs.

My favorite camera ever is the Leica SL2 and on this day it is sporting the 24-90mm zoom lens. I chose it because of the zoom as well as the fact that it is weather sealed so I can get it out in the rain without fear of it being damaged.

Below are a few photos I took while hiking down and out to the bridge, sometimes people will do the silliest things… lol.

Hope you enjoyed the extra photos of Tallulah Gorge at the end, I enjoyed capturing them. Until next time, 73.

WK4DS

Activated Cold Mtn K-6895 TWICE

Here is the AAR for two separate activations over a two day period at the same park. This is Cold Mountain State Gameland near Waynesville NC. K-6895. It is a great place to do some vehicle mounted POTA and I recommend it.

In this photo above you can see the entrance to the parking lot and how small this area is. I also ran out a single radial on the first trip as I was only going to be on 20 meters as this park doesn’t have cell coverage. I also didn’t know how well I would be able to do with this park as I did literally zero scouting before hand. I scheduled the activation as I wasn’t sure about cell service and this turned out to be a good thing.

I have learned to search out parking lots that are fully within the park boundaries. I do this by pulling the park up on a couple of map applications and then zooming in on the roads around them and scouring these areas for parking lots. Just like in these two screen shots I found the park boundaries pass over Lake Logan road a few times and upon closer inspection, I found what I was searching for… A parking lot within the park boundaries that I can operate out of the truck with is a luxury that I love to land on if at all possible. I didn’t take a man portable rig this time as I wasn’t thinking about POTA being the main reason for this trip but rather something to do if the weather got bad or I just got a hankering for some radio time (which is what happened)…

The radio for today was the sBitx v2 and I am learning more and more about it as I use it. The message memory is really nice with this machine. I really like the whole process of operating CW with this radio and FT8 as well. It is almost effortless. The dev that wrote the code for this radio is working on a v3 release… I guess is the version. I am not sure what version we are on at this point to be honest, but it does have a couple of issues that make it less fun to use at times, but to be honest about it I have had a blast with this radio.

Day 1 was nice because there wasnt anyone except a fly fisherman who was down in the river. Here you can see the radial ran out to the side.

Since I had come to this park and didnt know much about it other than it was a game reserve, it was nice to see that amateur radio wasn’t on the prohibited list of activities. Lol. Keep those activations low key and it probably won’t get added too.

Things got dark in a hurry since it was overcast as well. I ended up finishing the activation by flashlight. Here is a photography trick for you. Dont point the light directly at the thing you are using (here it is the logbook) but point it at the ceiling and the light will bounce back and fill the area making it easier to see and work.

Day 2…

The next day showed more fishermen than the previous day but still there was plenty of room to put out some wire radials. Today I wanted to get on 30 meters and see what I could do as the band was open… or so I thought. So I put out the radials for 30 meters and since they would reach the trees, I ran then horizontal from the antenna mount to see how they would perform as elevated radials. Turns out that was a terrible idea, the SWR was horrendous so I started playing with them a little. I next just laid them in the grass to do it the lazy way and the SWR still wasnt great, better but still fairly high. Lastly, I put down a stake and pulled just one wire taught and BAM 1:1 SWR! Seriously, that was all I had to do???

So I also scheduled this activation as well, but unbeknownst to me, I failed to convert local time to UTC time so the schedule was way off. So I was running dark mode. I called CQ on 30 meters and in ten minutes or so had made a whopping 2 contacts. At one poi t someone tunes up on top of me and starts calling cq as well! Lol. So I figured I would switch over to FT8 and see if the time was still synced well enough for it to work. Ten minutes into this I had successfully made two more QSOs for the log.

At this point I switch antennas and get on 20 meters CW and start calling CQ. I actually think at this point that the spot was working and there just wasnt anyone on 30 meters as I started getting QSOs in the log like normal but then it just fell off again and I decided to try 20meters FT8 and see what would happen and again I only made a couple of QSOs. Not sure why but it is what it is. I am happy at this point as I have the activation in the bag but still have a ton of time so I go back to 30 meters and the waterfall is covered up in activity. I am stoked! I setup and strt calling CQ… and I call…and I call and FINALLY I get an answer.

Over the next 12 minutes or so I work 3 contacts withthe band covered in activity. So I simply ask W4ELP if he would spot me and he said he would. Thank you Ed for the spot because you can see what one simple little thing loke a spot on the POTA website can do for an activation. QSO #19 is Ed and in about 35 minutes had made 19 contacts. This is awesome considering the lack of a spot on the network. As you can see, having the spot though got the word out and I quickly added another 36 QSOs to the log with a couple coming with nice little pile ups.

I learned a valuable lesson today in the I need to check the time on my scheduled activation carefully so it happens at the time I am there. Lol. The next one did happen right. Just like the Smokey Mtn National Park one. The RBN works great and scheduled activations making not having internet access a moot point. This is a fairly new practice for me so I plan to use it more in the future.

All in all I had a great trip to Cold Mountain and will probably go back the next time I go to Maggie Valley to photograph the elk heard since it is so close to the motel. Thanks for coming along and I hope to work you soon!

WK4DS

73

Activated The Great Smokey Mountain National Forest

Here is the after action report where I finally activated a park in North Carolina. The Great Smokey Mountain National Park is a well used park in the POTA network, but it was one that I had not yet activated in my travels.

This particular area is called the Cataloochee valley and there is a heard of elk in this area that I like to try to photograph in the fall. Well since I was here, had a radio and the elk were not very close either…why not POTA?!? I decided to activate this park the night before and gave myself a decent little window of time to get it done in as well since I wasn’t sure how the elk would be doing… I had remembered from the last time that cell service was nonexistent here so I scheduled the activation on the POTA site the night before just as a precaution. This is a pro tip, if you even think you are not gonna have internet, go ahead and schedule the activation and pay close attention to the time as it is UTC time on the website and don’t do like I did and get the time off by several hours because you chose the wrong time zone… I did this on another activation and the results are as you think.

I found this spot and setup the truck-tenna (a hamstick on a receiver hitch mount I made) and the Ten Tec Argonaut 5 for this activation to just get on the air as I wasn’t sure how long I would have with band conditions being not great lately, so I wanted to stack the odds in my favor as much as possible ahead of time. Well it worked… as you will see later.

Here is a sign that lets you know just how unpredictable wild animals can be… Elk are VERY large creatures so it is prudent to heed this warning… I also thought it was interesting that the park rangers have to put out these signs at all… I guess getting a selfie is more important than getting killed by a bull elk…who knows?

This is what i found on this day though. The whole heard was just chillin in the edge of the treeline, so it wasn’t too heart stopping of an event to photograph them on this day. It was fun to just sit and peer at them through the camera for a while though. I have a video on my YouTube channel that showed a few more photos as well as talks about the rest of the trip some more as well.

Back to the activation though… I ran the coax into the cab as it was kind of cool this morning so I wanted to stay warm while I operated and just ran the cable through the window and left it down a little while I did since it wasn’t raining. This 15’ coax is just long enough to reach in this configuration too, which is nice.

Here we have the operating position today. I just sat the Argonaut in the seat, added a common mode chock and hooked up the HamGadgets cw keyer and my N3ZN tiny paddle and I got on the air. Power for the radio is pulled straight off of the truck batteries if I operate from this location as I have a power cable ran to the cab from the battery with power poles on it just for this. The arm rest makes for a decent desk, but it could be better. At some point I plan to make a table top that sits on the arm rest and goes forward to the shifter and even has a leg that sits on the console to support it as well. This will probably be covered with some sort of cloth so it wont be so rough on the arms and will allow me to spread out the notebook, pen and key a little more.

I could tell that the scheduled activation on the POTA site was working as I almost immediately got a pile up once I went live on the air and the RBN picked me up. It is night and day different as to what you get with and without the reverse beacon network picking you up. One QSO of note here is the Canadian call on the first page. We had quite the QSO and spent a few minutes chatting about things before I got back to the activation and went to work on that. I am not one to shy away from a ragchew even though I wanted to work a bunch of contacts too, it is all about talking on the radio so I love all of it.

I had a steady stream of calls come in for a little over an hour. that is awesome! I love it when I am able to catch what I think is all the QSOs that are calling. The band was really strong today too as I was only using 15 watts and was able to get really good signal reports back from most everyone. It was a really stable day as well as it can also be seen in the log that the signal reports were steady and not sinusoidal. Sixty three contacts later I called QRT to go get some lunch and fuel for the truck before heading on to Ashville for the afternoon. If you are interested in the rest of the trip, I have a YouTube channel where I talk about the photography aspect more. Thanks for coming along and until next time, go get on the air!

72

WK4DS

Something special finally happened to me at a POTA park...

Today had been a pretty busy one at work, so afterwards I wanted to go over to K-2169 (Cloudland Canyon State Park) and just work some contacts to take my mind off things and to just relax for a while since it was 77 degrees on November 7th!

I get my sBitx V2 and head over there with the plan to run my hamsticks since I only have about 2 hours, maybe less, to get my activation in before dark. I roll up to the frisbee golf parking lot and notice another car in the lot with an antenna on the roof…a very large antenna mind you when compared to the ones you usually see on top of smaller cars.

I go ahead and park in my usual location and decide to walk over to see if there is someone in the car and THERE WAS! What do you know, I found another ham already doing POTA! It was none other than KB4QXI (John Law) and he was working SSB with a 20 meter hamstick on the roof of his car none the less. It only took me a year and a half and over 120 activations at this one park to finally run into another ham radio operator doing POTA. John had a pretty sweet system setup in his car with a computer, I assume for logging as I failed to ask him if that is what it was for, but I am pretty sure it is. He was also running a Yaesu radio of some sort on a mount that placed it right in hand’s reach but out of the way of the passenger seat, which happened to be where the computer was residing. I failed to get a photo of any of that so just let your minds run amuck with the verbal description and we will move on.

After talking with John for a while we agreed that it would be best if I setup in the next parking area down the hill which is right at 2/10s of a mile away. I personally figured that was far enough that we shouldn’t have problems with cross talk if I went to 30 meters since I was going to be operating with CW anyway since he was already on 20 meters when I arrived. I figured that if 30 meters was really bad that I could just drop down to 40 instead and work all the locals. Lol. Something else I had not noticed was that this lot had powerlines running right over it (as you can see in the above photo). I figured at this point I might as well give it a shot anyway and see if I could get the activation at the minimum. I did only have about 2 hours till the end of the UTC day at this point.

I setup three counter poise wires, you can see one of them in the photo I took above just barely because I forgot to get a closer photo prior to it getting dark… soooo. Suffice it to say, I ran out the two 30 meter tuned radials and even had the opportunity to run them elevated about 5 or 6 feet above grade, which is probably why my radio worked so well on 30 tonight to the point I didn’t move off that band. Tuned radials seem to work SO much better than radials that are just close. The key when I operate from the truck seat can vary between the Gemini and the N3ZN paddle, it just depends on the mood I am in as well as how fast I want to setup as the Gemini is in the carry tote and the paddle is in the hard case with the Argonaut 5… I normally choose my paddle based solely on things like this as I really like using them all.

After talking to some of the more code savvy hams in the email reflector on the bitx group and them helping me solve the code problem (actually they solved it and told me how to implement it), I was able to get the FT8 mode operational. It actually worked when you called CQ already and it had an issue operating when you would answer someone else calling CQ. It is a stop gap fix that does allow it to work but it doesnt work as efficiently as it should. Still it got FT8 working for me so I am stoked!

To be fair, this is Ashhar’s first iteration of this mode in his hand coded software he wrote and it does work so I got no complaints as it allows me to work the mode WITHOUT the need of an additional computer. He is currently testing a revision that works even better so I am excited to see what happens with that. In the photo above you can see the exchanges and the log entry for my QSO with K4SQL. This is all in the radio too!

On the way out, it was pitch black as it now gets dark at 5:30…uggg. Have I mentioned how much I dislike Daylight “Savings” Time? Well, I dont like it… This is a prime reason too. Even without DST being implemented, it would be dark at 8PM in November. Regardless, I had to use a flash light to break down my antenna tonight.

I powered down and quit before the UTC day flipped over as that would have forced me to stay two more hours to get a second activation in…lol. I do need one more activation at this park to get me over 4000 QSOs. I never planned on getting that many QSOs at one park to be honest, my only goal to start off with was to get 20 activations so I could get the repeat offender award, now I am well north of 120 activations and almost 4000 QSOs! By the time this blog post goes live, I should be past that mark.

Something else of note is that I am currently still logging my FT8 QSOs on my paper log and typing them into HAMRS as there isnt that many of them at this point and I can easily keep up with this quantity manually instead of learning how to export them from the radio and then add them to my HAMRS log electronically or even a new logging program of some sort instead. There will be a point when I will have to do that, but for now I can still get them in the log like this really easily. So till next time warm up the air waves with your radio and hopefully I will work you from a park!

73

WK4DS

2 x POTA Activations plus a new to me mode! FT8 has entered the chat!

I have been busy lately so I thought I would combine the AARs for two activations into one report. These went very fast, well, one of them did. the other did last a coupe of hours and involved me doing something very new for me…FT8…just not with the Penntek TR35. It was used to make CW contacts at the first activation.

The first park I went to was my hometown park K-2169 Cloudland Canyon State Park. This is my go to park when I don’t have a lot of time. I also can go to the Sittons Gulch parking area which is much closer than the top of the mountain by a solid 15 minutes of driving. Well, this is where I went and during the week, I can also get to choose my parking space most of the time too. Today proved a little tough but it worked out. When I got to the park there were a few cars already there and they were literally in all the places I like to setup, save one… So luckily for me there was a space in a corner like I prefer to use as it gives me room to deploy my counterpoise wires and not have to worry about people tripping over them.

I also only deployed a single counterpoise element today as well. I was curious if it would heavily affect my ability to make contacts with only a single radial, but it didn’t seem to matter much on this day. Due to my spot, I was able to run it straight away from the truck too for what that is worth. Seems that if I don’t use a radial at all, the hamstick will use the coax and the truck body for the counter poise and I will have about a 1.8:1 SWR on the nanoVNA, but if I simply add once tuned radial, it drops to 1.2:1 and if I add two it is pretty much 1:1 SWR. This is why I always deploy at least one if there is time at all, it helps with my transmission pretty dramatically. I found this chart online and used it as a reference to see what would be the results of better antenna SWR and as you can see, at 1.8:1 you lose almost 10% of your energy and at 1.2:1 you only lose about 1%. This is why I don’t worry about deploying both radials if I am in a time crunch. I also know that there are a lot of other things at play here like radiation pattern and take off angle, but it is pretty consistent since it is a ham stick every time and I cant easily change that.

Once setup I immediately jump on 20 meters to get things going today and it did not disappoint! 20 meters was alive and well on this day with a lot of activity.

Today’s weapon of choice is the Penntek TR35 Amateur Transceiver. I bought this radio last year for this reason alone and it took me a while to get around to using it as I was trying to get my IC-705 up and running at the time. I finally came around to the concept that the 705 just wasn’t for me and stopped using it. Sometimes a radio, even a wonderful machine like the 705, just isn’t the radio you want to use, so I sold it back in August. I kept this radio though as I really love the whole radio, literally the whole thing is as close to a perfect CW rig as I could get. It has every function you need on the surface that you could want and nothing you don’t need. The built in filters are really well done and it can even listen to SSB if you are into that sort of thing. The compact size also makes for another reason I like this machine, it is destined to be my new travel radio replacing the venerable Elecraft K1 that I also sold last August due to lack of use. I do want to add an antenna tuner at some point to this kit so I can use random wire antennas, but for now it has a tuned antenna in the kit.

This is the kit when setup. The Penntek TR35, the N6ARA Tinykey, a set of simple headphones (with an adapter to make it play out of both ears) and a 10 cell AA battery pack. I chose a 10 cell pack as it will give me almost 13 volts when the batteries are charged and I can use alkaline cells in a pinch by bypassing two cells with a couple of dummy cells I made in the machine shop. The kit also includes several pens, a pencil (since they don’t dry out), a Field Notes notebook, a couple of lengths of coax, one of which has a ferrite bead common mode choke built into it, a 40M EFHW antenna with an additional radial for it and a throwline with a weight, everything you could need to get the little machine on the air.

Here is another thing I like about using my truck for POTA, I can use the bedcover for a table and just spread everything out on top of it like you see in this picture. If I can operate outside I will always choose that option, but sometimes, the weather or time just prohibit that.

I had a good run with the little Penntek TR35 as you can see in the log. So if you wonder how well things can go, this is a 5 watt radio into a hamstick on my truck. It is one of the worst possible arrangements you can possibly come up with and I still ended up with almost two pages of contacts. Now if the bands are trash, then all bets are off, but you really don’t need a ton of power to do a POTA activation and have a good time. On to…

North Chickamauga Creek WMA K-3958

The next outing was in Tennessee at the North Chickamauga Creek WMA in Soddy Daisy TN. This little park has not seen a ton of activations and to prove that, just go to this parks page on the site and look at who (with only two activations mind you) in the top activator and also who holds the highest QSO count as of this writing. Yeah, it is me. There have been some people activate this park, but it just doesn’t get the attendance of places like The Great Smokey Mountains or even Cloudland Canyon State Park. I don’t understand why either, it has easy access and is pretty close to town. Maybe after I write about it and give it some notoriety it will see some more attendance…who knows?

I was here on a Friday during the mid day hours, so the park was pretty much abandoned except for me and a couple with their dog in the river bottom. I setup in a spot where I had room to deploy a radial and got the sBitx v2 out this time as it has a mode built in that the Penntek TR35 does not…well actually it has a bunch of modes that the Penntek doesn’t have, but this radio is special in that it will do FT8 natively in the radio. Yeah, no computer, no sound card, no setting up complicated software, no figuring out how to get the computer to talk to the radio and vice versa. You just choose FT8 from the mode list, dial up the frequency, set a few things like your call sign and grid locator and hit Call CQ. Now, the radio is a beta version of sorts and it has a few bugs to work out, one of them is currently in the FT8 section too, as long as I am calling CQ and a QSO ensues, the whole thing works like clockwork, but if I answer another operator’s CQ it has a glitch and wont sequence correctly. So I can use it for now, but only if I call CQ. Even so, it still works and I made almost a dozen contacts on this day with FT8, so I am happy about being able to use another mode on activations.

Here you can see a QSO has just finished with WD5BFH and the radio even logged it for me! Oh yeah, it even has a logging program running in the background to log your QSOs as well. I really like this radio.

Here we have the antenna layout for today, the single radial was really close to 45 degrees due to the slope behind the truck. That made the SWR even better and I was stoked to get on the air and see what I could find out there in radioland.

I am also testing the reserve capacity of this 8aH battery I bought last year off of Amazon, I keep turning the power up higher and higher to see if the battery can handle it and today saw me using 30 watts of power for almost two hours! I shut down the activation because of time constraints and not because of the battery so it works great for my needs.

Once again I was able to setup on the truck bed cover, and I am acutely aware that I need an easier logging process. Hand written logs are nice, but they are slow to transcribe. I am thinking that I too can come into the 21st century and use a computer to do my logging…I know, I know. I have really railed on battery powered devices, but at some point I guess I just need to bite the bullet and get a computer of some sort for logging. I am thinking of using a Linux based OS for this as these seem to be more reliable and do not update and crash all your stuff… windows, I am looking at you.

This display below is not how it looks when booted up for the sBitx V2 in the native configuration. I have scrolled it down to be able to see the top QSO in the logbook so I can confirm the QSO did in fact get logged when running FT8. The photo underneath this one is what the screen looks like when opened initially. The screen has more information than can be displayed normally so since it is a web browser layout, you simple scroll down to see the other intel. Things like the on-screen keyboard, the logbook and the macros (message memories) are what you find when you scrll down. But the way I have it here is an efficient way to run this mode for me as you can see everything you need on one screen. Sorry for the reflections, it was tough getting this frame outdoors.

This is the native layout at startup.

You can see the time stamps for the FT8 contacts are pretty spread out. This is a function of my operating skill level being low and the lack of “responding to other calls” being buggy with this mode. I know this because the band was on fire that day.

All in all I had a great couple of outings for POTA and radio in general. I hope you enjoyed these after action reports and look forward to seeing you again soon!

73

WK4DS

sBitx V2 Amateur Transceiver Mods for POTA Use

My newest radio, the HF Signals sBitx v2, is an HF radio with so many features that you just need to follow this link over to their website to see what it is capable of. Once you have finished going down that rabbit hole, come back over here to see what mods I have done to mine already for my POTA stuff. I want to say this right away, this radio is kind of in Beta, so if you don’t like to open up the radio and tinker with it in both the software as well as the hardware, this probably isn’t the radio for you. With that out of the way, let’s get started!

I decided to get in on this idea of a open source architecture radio design. I found this company, HFSignals, and they make several radios with their latest model being the sBitx V2. This is a touch screen radio with a huge screen and it is powered by a Raspberry Pi SBC. Using a legit computer to power the radio unlocks so many things that this radio can do that other radios can not do. For one, it will do FT8 IN THE RADIO! Yeah, no external computer needed at all, that in itself is a gamechanger and don’t be surprised if you see the big names in the industry doing this in the near future because of it. By using a Raspberry Pi SBC for the brains, this little machine is just chocked full of goodies that those other radios cant do.

FT8 is native inside the radio on the sBitx v2.

You heard that right, as I type this blog post it is on the bench next to me finishing a QSO with I1RJP, and when it does it will automatically put the QSO in my log for me. How awesome is that? Did I mention it is open source? Yeah, both the software AND the hardware are open source and it is encouraged to take your radio apart and tinker with it. Shoot, it even shipped to me with a spare set of output transistors in the accessory bag. These are well thought out but they are still rather simple overall designs with features like they are passively cooled radios and use a crystal filter network. Another thing about being passively cooled is that it means there is no fan noise to deal with at all this way, since there are no fans.

Well… I used it on a POTA activation and the little radio got HOT. Really hot to be honest. So I decided that since this radio is designed from the outset to be open source and to be tinkered with by the end user and I wanted to use it for POTA activations, that I would add some fans to cool the little machine on activations.

The first thing I wanted to tackle was the power amplifier heat sink. It is a great heat sink and does a wonderful job as it became really hot during the activation. I first started looking for a suitable fan in my junk box and found the perfect fan in an old computer power supply that I have cut apart for another project. The fan was still mounted in the sheet metal case which also happened to fit perfectly over the outer edges of the heatsink. All I needed to do was trim the sides down so it sat next to the heatsink and add some screw holes to attach it with.

Once I had it mounted with a couple of self threading screws, it was time to get it running. I went inside the radio and started looking for a suitable place to tap power out to it and found the incoming source point was the best, but the fan would run all the time if I used this spot…

Enter a simple electronic circuit that could be used for any temperature of fan control and could even be adjustable with a potentiometer if you were so inclined. This circuit is a simple power transistor rated for 6 amps of max draw (I used this so it could handle the 300mA of draw from the fan and not need a heat sink and they are still really cheap too). You simple have a voltage divider network for the base of the transistor where you have a fixed resistance between the base and ground and you add a thermistor (a temperature reactive resistor) between the voltage source and the base.

I chose a 10K ohm negative coefficient thermistor for my needs as this design has the resistance go down as the temperature goes up. The fan is simply wired in series with the transistor’s collector and the voltage source and the transistor is basically used as a electronic relay in the simplest form. I know the MOSFETS are more efficient, but this works and I had all of these parts (except the thermistor) on hand so I used these instead.

What happens during operation is that when powered up, the thermistor has so much resistance at a lower temperature that the base voltage is less than the .7 VDC required to bias the transistor since the fixed resistance of the base to emitter side of the voltage divider is calculated for the desired temperature. The thermistors have a chart showing the resistance at different temperatures so you can make these calculations fairly easily. Mine worked out to 270 ohms for the fixed resistance between the base and emitter. So you can imagine that with 10,000 ohms (at 77 degrees) on the other half of the voltage divider you only get .363 VDC on the base of the transistor and the transistor stays “OFF”…

I found the above chart online for 10k ohm thermistors and grabbed it for reference only. This may not be the right chart for your thermistor as they have different resistance curves so check with your brand of device and make sure you have the right chart for your device. Back to the story in progress…

Well knowing this, as per the chart above when the temp rises to about 107 degrees then the resistance drops in the thermistor to about 4980 ohms and this now allows about .7 VDC to develop across the base of the transistor, forward biasing it. Notice how I made the contact with the hear sink. I soldered on a pair of wires and put heat shrink tubing on them to insulate the connections then I ran a 1/4-28 tap down into the space between two fins cutting something resembling threads into the fins. Then I took a piece of a zip tie and put it on the thermistor and ran a setscrew down against the ziptie/thermistor stack to hold the thermistor against the heat sink it works really well too. The ziptie is only there to do two things, to prevent me from cracking the outer shell of the thermistor and to insulate the thermistor from the setscrew so the setscrew wont bleed off heat, I am not certain it helps, but it sounded good in my head at the time. LOL. I located it near the transistors so it will pick up the heat faster. I also changed the mica thermal spacers out for aluminum ceramic instead as those are supposed to conduct heat significantly better between the power transistors and the heatsink.

The fan control circuit can be seen on the perf board next to it in this photo.

Then once things heat up the fan spools up and blows on the heat sink, in turn cooling it down to the point where the temperature on the thermistor drops enough to raise the resistance back up and shut off the transistor again. This worked like a charm at the last activation I used the sBitx v2 on. The fan doesn’t even come on to drain the battery until the heat sink warms up enough to need it, so if your simply listening around or hunting activators and doing search and pounce, then the fan will not cycle on very often at all… if ever. I do understand that there is some current flowing through the resistor network all the time though as well, but it is low and I am not really worried about 3mAs of current anyway. I have really large batteries in the grand scheme of things and if I am going to hike with a radio it will be the Penntek TR-35 anyway…

The next “upgrade” I did to mine was to add a heat sink and fan module to my Raspberry Pi 4 SBC (single board computer) that is the heart of the sBitx radio. The original configuration has the SBC mounted right on the RF board with very little space between the two for airflow and no room at all for a fan of any kind as you can see above in the photo with the side radio cover removed. I did some experiments with positioning fans above the heat vent opening above the Pi and could feel that the air I was pulling out was quite warm. This led me to the assumption that the SBC would run smoother (and probably last longer) if it had a proper heat sink installed on it. You see as my unit would run, with time, it would start to lag a little from information input, like adjusting the VFO would result in the numbers jumping on the display instead of a smooth change as the knob is turned. I noticed when the fan was pulling air across it that this would be reduced significantly if not eliminated. So the mission became “how do I get a fan on this thing to cool it properly”

So I start looking at adding an external fan but ultimately that didn’t look really feasible as I wanted to pull the heat off of the Pi properly and not with just slight air movement. A case fan would only help a little and I am pretty sure at this point that the SBC needs a little more help than that. Enter a riser kit from amazon and a heat sink assembly with fans from one of those Raspberry Pi bundles that comes with the pi, a small case and a heat sink with fans. I measure every thing and come up with a height to elevate the SBC and check the cabinet and sure enough, there is plenty of room to add it. So I get it all together and when you get the riser kit from amazon, you get the little screw-in standoffs as well as the header socket extender to extend the pins up to the Pi once installed. If you will look closely in the photo below, you can see one of the fans and the heat sink fins for the SBC heat sink that I added to the Raspberry Pi SBC to help cool it.

In the above photo you can see the pin extender i also had to add so the Pi would plug in once elevated for the heat sink module. This worked wonderfully for fitment and I was stoked to have the heat sink on the SBC finally, but I still had to connect the fans to power to get them to run. Instead of putting them on a heat sensor, like the power amp fan, I chose to wire these straight to the main power switch on the sBitx so that when you turn it on, they spool up and run the whole time. My reasoning is that the computer will be working the whole time as the radio is in constant “refresh” mode so to speak as the sBitx software package has to keep everything up to date in real time on the display, then there is the background applications that are also running like the telnet server and dx cluster stuff and the other applications should they be active. Logically the SBC will be running nonstop, so lets just run the fans all the time…

This is where I run into a problem…

Did you notice where I drew power to run the fans? That seems completely reasonable for someone who just successfully wired up a fan on a temperature sensing circuit for the power amplifier. Well, it turns out that the fans for a Raspberry Pi are not 13.8VDC fans but rather 5VDC fans as they are designed to be plugged into the SBC IO header bus and not driven from a 13.8 VDC source. Let me tell you something, when you run a 5 volt fan on nearly 14 volts it sounds like a jet engine preparing for take off! On top of that, I had a pair of them!

I had brought the radio to the house and connected it to power to play with it and hunt some POTA activators and the whole time I am thinking to myself… “Man, these tiny little 25mm fans sure are loud…” but after about 10 minutes (yes, they lasted that long and in fact lasted much longer) I started to smell hot plastic… I shut down the radio and took it apart to find the fans incredibly hot and seriously, “soft” to the touch.

Back to the workshop and I figured out what I had done. So I start working on a way to lower the voltage that would not cause RF hash inside the radio cabinet. Those little buck converters from amazon are notorious for causing RF hash so that was out. This simplest thing to do was to put a big resistor in series with the fans. I had put them on a 5 VDC supply in the shop and measured the current draw so it was a simple matter to do a little ohms law and come up with about 50 ohms of resistance to mitigate the excess voltage from the supply. Also these fans pull very little current and I am running them at 4 VDC instead of the full 5 volts as they are rated to run from 3.3 to 5 VDC. This way they will be a little quieter too or at least that is my thinking and it gives me a little leeway should the voltage go down lower or even a little higher.

Inside this heatshrink is (4) 200 ohm 5 watt resistors soldered in parallel so make a 50 ohm 20 watt resistor.

Well the brute force approach worked and the (4) 200 ohm, 5 watt resistors in parallel dropped the voltage down to a very workable level. The resistors dissipate about 1/2 of a watt of heat total so I put them out of the way from everything else and it works, it just works. Maybe later I will add some sort of active voltage regulator and do it so that I don’t have to just burn off the excess power nonstop to keep the fans at the right speed. Maybe something like a 555 timer biasing a mosfet for pulse width modulation to keep the power draw down and keep fan speed at a constant level. I don’t know, I will look at that later, for now, the brute force resistor idea is working just fine.

Once I got the fans turned back on, I found “I had a rod knocking” in one of the fans… figures that if you run them at almost 3 times the rated voltage that something like a bearing fails in the fan… well I just ordered another set from amazon and swapped them a couple of days later and now we are all set. So it would seem at least as when I went to reassemble the radio I found that my USB and Ethernet ports no longer lined up with the openings in the side plate for the radio.

Turns out that if you have a fully equipped machine shop, this isn’t a real problem though. It could have been solved with a good file and probably a half hour of work, but who wants to do that if you have a CNC milling machine at your disposal? So I put it in the milling machine and manually open up the exiting holes to allow use of the ports and by default I also created air vents for the Pi to get fresh air to it much easier now. This also seems to work really well for the time being. Better air flow, adding a heat sink and FANS!!! The Pi runs cool now.

I also did a couple capacitor mods that I found on YouTube as well. A fellow on the interwebs had done these same capacitor mods and they made sense to me so I went ahead and added them as well. The following video describing these mods and why.

To summarize his video, he added decoupling capacitors to the three jacks on the side of the radio to drain off stray RF. He also adds one across the incoming supply lines to kill transients and possible RF on the power. Please note that in the photo below I have the plus side marked on the capacitor, this is incorrect as the board is marked erroneously and I translated that error to my cap as you can see in the photo. Check the supply on your radio with a meter before installing caps that can not be reverse biased. We all know how that would end…

One last thing I also did was to add some heatsinks (also per the video above) to the power devices inside the radio to help them survive use during digital modes. They worked just fine when I ran them with CW but when operating digital, the duty cycle is a lot higher so I didn’t want to risk thermal failure because of something as simple as adding a heat sink. This also comes from the above video and just made sense to me too, so I added them. The radio operates great and I really like using it for FT8 when calling CQ (more on this later) as well as for CW. I have some other mods planned for the future so another blog post describing these mods will be in order at some point. Till then, thanks for your time and attention and I hope this helps someone out there with their radio.

WK4DS

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