POTA tip for a CW op…
Today I activated US-2169 with my trusty TenTec Scout 555 using CW and realized I needed to share a “trick” I use every time I go out…almost. But first I wanted to share an update with the shack…
So, to lead off, my “hunter” station finally went through an update. I tore out the entire system to get the TenTec Omni 6+ station out as it needs some service.
This took three days to get it broken down, sorted and separated and finally reassembled without the Omni 6+ station so it can goto the Radiosmith for repairs. I was going to just sell it for parts, but since posting about it I have had several Hams email me about what is probably the problem. This isnt near as bad as I first thought so I will hopefully be able to use it soon.
This is what it looks like to break down a normal ham shack so you can remove a part THAT IS ON THE BOTTOM! Haha. It figures that the bottom radio would be the one to fail on me first. It was during this transition that I had the Yaesu FT-736 go down too. Coincidentally at this exact time…. Hmmm.
Here is a link to a short video about what I found, Link to video: https://youtube.com/shorts/pQbP4yRiXAg?is=4TWSAL9qMet0UAhd
The long and short of it is that I did some troubleshooting with my oscilloscope and found that I had audio coming into the audio processing board at a low level but the board was essentially dead. The audio amplifier IC only had .556 volts instead of 13.8vdc which is what it was supposed to be… So I tore the radio apart and had trouble with the connectors on the board. The connectors were really tight and I was chewing them up to get them to release. Instead of destroying it in the attempt to get it apart, I started looking at the power delivery and found that it was probably a bad solder joint or something like that. I decided to run a fresh power wire and solder it directly to the audio amp IC. I added a 1 ohm resistor as that was in the original print so it would work properly and POOF! It came back to life!
Once this repair was done, I was able to reassemble the stack and get the radios back on the air.
This is what the station looks like right now. Once the Omni 6+ is out of the shop and back in operation, I plan to sell the Omni 7 as I really want an Elecraft rig in the shack. I am thinking a K3 or K3S, but I am without an Elecraft radio at this time and that bothers me a little. I like the Omni 7 but it just doesnt scratch the itch for me like the Omni 6+ does. You can also see the Scout 555 band modules in this photo, I finally got the holder out an added to the shack for those too. Look at all that space that I have now, thanks to a tip from KG4WBI about some adjustable stands, I was able to elevate the radios and that allowed me to store the CW gear underneath them…
On to the park activation!
Today, I chose to operate on just two modes, but. I wanted to run 5 bands. this can be accomplished with just one of the radios I used, the sBitx, but I love using my TenTec Scout 555 for CW so I brought it out for that mode. The sBitx is a joy to use on FT8 now and JJ’s crew has it working even better on the current release of the software package.
Just scroll down a couple of posts to see my thoughts on this new release. I setup on 15 meters first as it looked like it was doing well. I only got one CW and one FT8 contact on that band! Well, deflated by this reailty check, I went to 20 meters to get the activation locked in before I wandered off to the higher bands to play. Well, even 20 meters was not that great, I finally got the ten I needed to lock n the activation while there, but it took a while. A lot longer than it normally takes me to land 10 contacts from Georgia, that is for sure.
After that I moved up to 12 meters where I worked quite a few DX stations as well as several US ops on FT8. I dont remember if I worked anyone on CW, I really dont think I did, maybe one… The bulk of the QSOs was on FT8, I finally decided to give 10 meters a shot… this went really bad. I think I made one contact on 10 meters before I gave up and went to 17 meters to see what I could do. I worked a few stations there and finally called it quits after about 2 hours with 23 calls in the log.
I have absolutely fallen in love with these silly little radios. They make such great CW machines! They also work pretty good for SSB too but I dont use that very often. I think this was a great idea from TenTec and I for one am glad to be able to have a few of these radios.
They do have a fault at this age though. The audio from the speaker is not great for weak signals. All of my Scouts exhibit the same issue. There is a low level “whine” on the audio. Something inside the radio is adding this noise. The answer for this is simple…ear buds and minimum volume. That is my trick. Use earbuds and turn the volume way down… This is an old trick I was taught years ago to be able to hear weak signal CW…….
Could I tear into the radio and find the problem in the radio audio chain? Yeah…is the juice worth the squeeze? Not really when I can use this trick instead. Ear buds work better than headphones as they require a much lower level of power. What happens is the internal radio noise is not amplified in the later audio chain when you do this. It is really neat how the signal will just float to the surface as you get the volume just right. It acts almost like a rf gain of sorts. There is a sweet spot as minimum volume will just show you the audio noise in the radio. But it you look at the volume knob in the above photo, you can see where I was running it at. I also find that if you open up the Jones filter a little, weak signals will get louder too. You can see where I run this adjustment as well in the photo above.
These two photos show the power system and the antenna matching system. The power was delivered via a 36aH LiFeP battery from Amazon, which is plenty of power for a radio running 40 watts. Like 4 hours of constant transmit levels of energy. All day for normal operation…
The antenna tuner is the MFJ941 as it has connections for a wire antenna built into it. I like this tuner as it will match a pretty bad antenna to your radio pretty easily. I use the nanoVNA to set the tuner and just plug the radio back into it when I get the trace happy on the VNA. These things are the best antenna analyzers on the market in my opinion. I can buy litearlly a half a dozen of these instruments for the cost of one commercial antenna analyzer. Not to mention they willl do many more things that a analyzer will not do…lots of things.
Below shows the antenna and I am pointing out where it is attached to the tree. The top of the wire is probably 25’ off the ground and comes down to the corner of the pavilion at about 7’ above grade. This worked well today but I have no idea what the radiation lobes look like. Since the wire is 41’ long, it has to be crazy on 12 and 10 meters but I was able to make some contacts so it was good enough. I like running wire antennas when I can, they seem to pull in weak signals better than my telescoping vertical.
The next two photos show the display of the sBitx running version 5.4 software. There is alot of data, but it isnt too much. I am running the native FT8 application here and the bottom photo shows me working PU7MJD in Brazil on 12 meters. This is why I wanted this radio. When the other modes are dead (no one was running CW on 12 meters) then I can still work someone.
The color coding of the display is great and easy to use!
After a couple of hours of operating, I called it quits for the day and packed up. These are the kinds of activations that I actually enjoy. There was no pile ups today and I made over 20 QSOs too. FT8 is an easy mode to use on the sBitx and allows me to do things like get photos for my blog while it sends CQ and such. I still like to drive the radio though so I dont just let it run free. I need to test the CW keying on my next outing to see how much it also improved.
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Until next time…73,
David
WK4DS