My activation with 9/10th of a watt… on CW.

Today marks a new milestone for me. I did a complete POTA activation with less than 1 watt of transmitter power. This is only 18% of my normal power of 5 watts. The numbers seem impressive now but just wait.

I went to K-2169 to get a quick activation in before they closed the park gate as I had almost two hours of time to do it.

I have several things that would be considered road blocks to this being possible.

The first one is the power obviously. The second is I am running that power into a hamstick antenna, which is not known for there efficiency. Lastly I setup at the foot of a mountain, literally… so let’s see what happened.

Spoiler alert…it went really well. I did have a bit of a rocky start as I wanted to get on 40 meters first but no one was there from what I could tell. After a solid 5 minutes of calling CQ I got zero answers, so I checked the spot page and saw there was a bunch of activators on 20 meters, so I changed the antenna to 20 meters and got on there.

Things changed when I did this. My first contact was with Paul KJ7DT in Idaho! That is right at 1780 miles on 9/10ths of a watt! He even gave me a 559 report, which I couldn’t believe! Wow, this just might work!!!

Well, as you see in the logbook, it went surprisingly well and I was able to complete the activation and get back home well before dark too. This was a pleasant surprise to be honest about it. I have turned down my power before but never this much. Now, I am going to do a series of self challenges to see how low I can take the Icom IC-705 for output power and still get the activation.

There is an award from the QRP-ARCI called the 1000 miles per watt award. I won this award at least six times today (if I were to actually apply for it that is). That just boggles my mind. I think my furthest contact was VA7AQ in British Columbia at about 2120 miles. That comes out to 2355 miles per watt!!! That is crazy!!!

Radio waves are a strange thing sometimes. If the sun is cooperating and the earth is also happy, it is easy to get across oceans with just a watt or two of radiated power. I plan to test this theory more this summer as the solar cycle improves even more towards the maximum.

What really impressed me is with POTA you normally send more honest signal reports than in say a usual DX pile up or a contest. If you will notice, 20 meters was going strong at that moment and almost everyone was booming into my IC-705 in the rain that day. (I was inside the truck but it was raining). 9/10ths of one watt is what most hf rigs would consider the pre-amp stage. Lol. So the next time you have 100 watts and 2:1 SWR, dont sweat it too much, you still have something like 90+ times the radiated power I was using today. That should make you feel a little better about it. Haha. Until next time, warm up that atmosphere!!!

Addendum: Well I now have to get crazy low as Thomas (K4SWL) has a video where he activates with 100mW of output power… more to come…

POTA in the rain, it is still fun if you go prepared for it.

The fog was incredible on this day.

If you knew that I had already written this post once already…my rapid fire mouse press killed the first one. So here goes again…

Looking at this now, I look like an old wet hen in this photo…lol.

This day started off with a lot of rain and a ton of fog at the top of the mountain. I got to the location and found it to be thoroughly inundated with water and it actively raining making it even soggier…if that is even a word. Once I found the parking space I like… right smack dab in the middle of the parking lot, I proceeded to setup my antenna.

The antenna is the 20 meter hamstick but since it was raining so much I added my drip proofing kit to it with the empty peanut pack. This peanut pack is metal foil so it is probably interacting with the antenna somehow, but I don’t know if it is as I have not checked yet…

Even with the rain, setup is fast and the system just plain works. Even with it slightly detuned, I still was able to work a little over 40 stations in about an hour. This antenna (a hamstick) with tuned radials just works really well, even with QRP power levels. It takes about 3 or 4 minutes to screw the sections together and spread out the radials and then it is back into the dry truck for the rest of the operations.

Here we have one of the counter weights that holds my radials taught without having to use ground stakes or ropes or anything. Also of note is that it is raining so much that the grass is literally flooded around the truck with a couple of inches of standing water in the grass. I was hoping this would help my antenna, and it may have, but it being detuned hurt me more I am sure…

Just lay the radial in the water, it will be fine…

As you can see here I tested the system once I got into the truck to see what the center of the SWR null was and is it at 13.9mhz, which is about 150khz below where I set it when I first tuned the antenna. Once it stops raining, I plan to have a session where I hook up the antenna and check it again, and probably retune it with new radials and possible tune it to 14.1mhz to get the antenna closer when deployed wet.

The radio of choice for today’s adventure is the Penntek TR-35. I chose it because of the compact size and the fact that it is just plain fun to use. The compact size allows me to set everything up on the console of my front seat in the truck and I still have room to log. That is a big perk of this radio, it is so small that it literally just sits in the corner of the space out of the way and it has a dedicated knob for everything I like to change while operating. What a dream little radio… I cant wait to get a shot at operating the TR-45L at some point, that is gonna be sweet.

My mobile POTA setup currently, as of 2022.

Another big deal about this radio is this feature pictured below, this is the menu for the memory keyer. Yes, it has two memories and that is the perfect amount to have for an activation. More would be better, but two gets me a CQ memory and a closing memory. By having these memories I can do some house keeping between contacts at times like add times or park numbers and such to the logbook. This is super helpful when there is a pile up as I like to document time, band, call, and signal report. This is just my preference though and is not needed for POTA, but it does help when someone sends me a QSL card as I can confirm the contact properly.

The take away from this activation is that you need to check your resonant antennas if you plan to operate in inclement weather as they can change and your radio could see high SWR and not get out very well or worse, it could be damaged from excessive SWR… So I like to check the SWR occasionally now to make sure things have not changed and if they have, that they are still within operational parameters so I can activate with out fear of damaging my radio. All in all it was a great day as I netted 42 contacts in about an hour and this is a great trip for me. I operate alone almost exclusively so I have to do everything myself, this is why I paper log while activating and then I enter the log into the HAMRS app once I get home. I have a wireless Bluetooth keyboard that I use with my iPhone and it goes really fast that way. Thanks for taking the time to read my blog and please hit the like button if you liked it.

Get out there and get on the air!

David

WK4DS

72

The Penntek TR-35 activates POTA K-2169 gloriously!

Click on the image to goto the WA3RNC website to get your very own TR-35 in either kit or factory built versions.

Today started off like most others with some time at work in the morning and then I had a few hours around lunch to do an activation. In addition to the usual activities, I have been using a variety of radios lately to see what I like about each one. Since I had activated most recently with the IC705 (by far my most favorite POTA machine) and so I wanted to use a different radio. I have been using the TR-35 lately in the shack, but wanted more field time with it to see how easy it would be to work with.

33’ wire radiator and two 10’ counterpoises bundles for storage. I love these velcro tie back straps.

So on this outing, I used a 33’ wire “vertical” antenna that I pulled into the tree with my throwline. Once the vertical was up, I laid out both of my counter poise wires (I think they are 10’ each) and for good measure I spaced them into a v pattern for kicks… On my next trip out I plan to see if putting them at 90 degrees to the radiator and 180 degrees from each other helps, it probably does and I have been paying the price all along with my silly V setup I have been using… lol…anyway…

This is a great antenna tuner and still happens to be in production! The new version is a little more streamlined but it is the same internally as this older one.

Back of the antenna tuner is just as busy as the front!

Once the antenna was up, I connected it to my MFJ travel tuner to the random wire lugs on the back of the unit. Then I use a special coaxial cable I bought from Amazon that has a BNC on one end and a PL259 on the other. The antenna tuner uses SO 239 mounts on it so the PL259 couples that end and the other end is natively a BNC on the TR-35, but I have also adapted my nanoVNA to BNC as well for simple tuning. Since my Ten Tec Argonaut 5 is SO 239, I have bought an adapter to convert it to this same system so I can tune the antenna easily on it as well.

This is not my idea, my late friend K4GC Brian was the person that taught me and Roger how to do this. It makes perfect sense when you think about it though so I started doing it once I got the VNA. Otherwise it is this trick of tuning till you hear the noise level peak and that is the best you get. This way works but it is possibly not centered where you need to be. Since the TR-35 doesn’t have an SWR meter, it has lots of protection circuits built in to prevent you from damaging the transmitter from tuning or operating at full power with poorly matched antennas. It has a current protection circuit as well as a thermal protection circuit, if either one activates, you really should check the antenna and see what is wrong, then reset the radio and try again. Alternatively, you could bring an SWR meter with you to get the tuner set as well if you don’t have a nanoVNA…

Amazon is a great place to find these sorts of oddball parts, several of the items in this blog today came from them.

Since everything is now BNC connected, I can quickly pull the cable from the radio, then connect it to the nanoVNA and see the tune on the tuner visually! I run a trace with the smith chart and a trace with a SWR line graph as well, with both of these running at once, it is pretty simple to get the SWR and the impedance really close to what the transmitter likes. Once I get the tuner adjusted to the band I want to use, I simply move the coax back over to the radio and off I go…

BNC is where it’s at with this system…

Here I am tuning for the 17m band, note that the VNA is showing the SWR of 1.541:1 and the impedance is 54.8 ohms and slightly inductive at 18.096mhz. I could dial some more of this out with the tuner, but it becomes a law of diminishing returns at some point with the tuning and this worked just fine. Note also that the SWR is fairly flat in the range I planned to work in also. (the yellow line represents SWR vs. Frequency)

Some things to note about the TR-35 that I noticed. The first one is that the headphone jack is wired from the factory for a mono plug, not the stereo plug that every set of headphone made in the last 30 years uses…why? So you go to Amazon once again and buy this little adapter to convert your normal headphones to a mono plug… You can go into the radio and change this on the circuit board, and the instructions even detail this mod, but you have to risk damage to the radio and it is a lengthy tear down and assembly process to get the board out of the case. Lot’s of chances to break something important if you asked me…so the adapter it is… Another thing I cant seem to master is the keyer programming. It is a simple operation to input the message into the keyer, but upon playback, it has odd spacing and sounds disjointed for some reason, I have tried slowing down the keyer speed to no avail, I will figure it out at some point, but for now, I don’t have that one working right. To put it plainly, it just sounds wrong on playback, like I was saying, it could be my sending is causing it, but I have not figured it out as of this writing. I have seen videos of it working as advertised so I am confident I can get it to work…eventually.

Amazon…they have literally everything at this point.

I powered it with my battery I use for my 705 activations, actually lots of the accessories I used came out of the 705 kit today for this activation. But I found this battery is way overkill for the TR-35, so I plan to get a smaller one for the travel battery to build the kit with. Probably something in the 4 or 5Ah range instead will be fine. I am also going to eliminate the voltmeter inline for the travel rig too, just a cable with power-poles on one end, the 2.1mm plug on the other and a fuse in line with the power. It pulls 5 watts wide open, does it really need 14 gauge wire??? Lol. I actually used the power cord for my IC-705 to power this radio today, the connector worked just fine. But I will make a cord just for this rig to go in the kit.

I am also still using the N6ARA tiny 3D printed paddle that I bought a while back(also from the 705 kit today) this is a device that although I like it, it has some problems that I have found. For one, it is really small and I didn’t take that into account when I bought it. It is available in a couple bigger sizes and I should have gotten one of those. This one is in my mind, one that should be a backup or a SOTA paddle or something like that as it’s main advantages are that it is light and small. What I have found from using it regularly is that is gets dirty contacts and you have to mess with it some and clean the contacts before it will send right once it gets some age on it. This is because it is plain copper/brass contacts (pc board with a brass arm on the “levers”) and they tarnish in a matter of days to the point it wont send properly till I clean them. I am looking into three solutions here, a nice travel key like the Begali travel paddle, make my own travel key, or buy a used small foot print paddle off the boards. I am actually leaning towards the Begali for now to give me time to design a key I can share with the world as well as for my personal use. Anyway, who doesn’t like a nice Begali key?

My N6ARA tiny paddle… I love this little key.

I have an alternative reason for working with this radio so much as well. I am going to be doing some traveling in the coming weeks and months and I want to take a radio that is not too large so it is easy to pack and carry around and such. This means smaller is better and the TR-35 is my physically smallest radio. This means it gets the nod based on size and now it also gets points for performance. Even if I cant figure out how to program the memory right. 😂

The kit will fit into one of several of my camera bags that I currently have so I don’t have to purchase a new bag to carry it in. I have found that camera bags work really well for QRP radios too, they just fit really well into old camera bags for some reason. By the way, I didn’t think of this idea either. I got this idea from my cohort KV9L who did this for his FT8 rig and I straight stole the idea from him. LOL.

Parts everywhere today! I took the IC-705 bag to “rob” all the support gear from so it would be a simple deployment and I have not built out the TR-35 go bag kit as of yet either…

I really like the aesthetic of the TR-35 as it has everything you need and nothing you dont. It really is an incredible little radio. I didnt build mine from a kit, I bought mine factory built and aligned so I could get on the air sooner.

1 hour on the air netted two pages of QSOs! That is awesome for me!

Logbook looks good with a good spread of contacts today with several from Canada in the log for a change. I usually only get one or maybe two Canadians and today I think there are at least four! This was with only about an hour on the air too. That is really good for me since I run QRP power. The map below shows how far 5 watts into a wire vertical will reach with a little understanding of how to use it. All in all I really like the TR-35 from Penntek, it a great little QRP radio that fits into what I enjoy doing in amateur radio, low power CW operating…

So if you have not done it yet, please like this blog post and if you have a RSS feed, you can sign up there too. I really appreciate your reading along today and if you have not done it yet, get your gear out!!!

Thanks and 73

David - WK4DS