When the bands are terrible…do this.
The most recent POTA activation caught me off guard. You see, I failed to check the space weather and just went to a park all willy nilly expecting to make tons of contacts without much effort. What happened was very different from that.
I had dropped off the wife and daughter at the airport for a trip they were embarking on and wanted to get some CW time in. So the nearest park that I wanted to activate was US-0716 (Chickamauga Battlefield National Park). I head down to the park and get off the main road to one of the side roads to get away from any stray RF hash that might be around. There was some on the main road on one of my previous trips here. I found this little pull off you see here for a trail head and get the truck situated so that my radials wont be in anyone’s way and start setting up the radio stuff.
Today sees the deployment of the telescoping whip / vertical again, but this time I wanted to do some testing before getting on the air…turns out I didn’t need to be in any hurry as the bands were terrible and I just didn’t know it yet. So once the antenna is up, I connect the nanoVNA directly to the antenna connector and start tinkering with the antenna to see what it would end up at as a native impedance.
What you see above is the antenna on the mount I made for the hamsticks that I have been using, but without any radials installed at all. It is very broadbanded and at 14.000mhz it is about 104 ohms of impedance. So to use it as is, the antenna would need a 2:1 transformer. Using the calculator on this website will give you the turns ratio you will need and you can work out the number of turns based on just playing with the info a little. I am tempted to make a transformer and see if it corrects this like I am thinking. I have some cores to work with so it is possible. I just need some time to sit down and do it.
Till then I will simply add some radials to help balance the system to see what I can do that way instead. As you can see below, I was able to work out the impedance issue to the point of usability but just playing with the radials for about 5 minutes. This also gives the RF something to “push against” so to speak so the antenna should perform much better than using it with just a transformer and no radials. That is my understanding anyway, and to be honest, RF energy is kinda dark magic anyway and does things that break the laws of electricity… I played with it some more and got it down a little better to right at 60 ohms of impedance before I stopped and got the radio out. 70 ohms seemed to be where this antenna likes to be with a couple of radials attached to it, so we will be making up a test transformer soon to see how this will work. I am genuinely curious at this point to see.
The radials don’t seem to make a lot of difference if they are not tuned to the frequency of the RF past a certain amount. They will always make a difference, but non-resonant radials seem to only help so much. Like you see below on the VNA. I ran them away from the truck as well as along side it to see how much the truck body interacts with the radials and it is quite a bit. So this system is honestly never deploy-able without some tuning due to the interaction with the truck body. This is fine with me, but it could be a deal breaker with others trying to setup super fast.
So I setup in the truck cab again today and used the Ten Tec Scout since I wasn’t going to go past 20 meters, I didn’t even get out the other band modules this time, I was just going to hop on 20 and have some fun. I soon found out that not even the vaunted 20 meter band was doing well today…due to the sun.
Paired with the Ten Tec Scout is my Begali Traveler key and my Hamgadgets Picokeyer. This combination is a joy to use for POTA and I look forward to using it when I can. The Traveler is a great key and I really like how the fold out feet are designed to protect the paddle blades when the key is stored. As you can see, I got the case for the Ten Tec Argonaut 5 out and used it for a table to hold up the radio and get it out of my way. This permitted me the space to be able to use my new-to-me Dell Inspiron 14” computer I bought for logging POTA ops with. This tiny little machine works great and can get me by in a pinch for photo and video editing too, even if it struggles a little with those tasks. I have about 160$ in this machine and I figure that isn’t too bad for a great little logging machine.
My cell phone plan is so old that I don’t have the wireless hotspot feature on my plan so I don’t have internet on the computer when in a park. because of this, I only use it to log the contacts and then when I get home, I will get online and upload them at that point. The 14” version is small enough to fit in the area you see here and lets me log in real time so now I am not having to key in all the times and all that. It is nice to log with a pen and paper logbook, as it doesn’t need a battery to retain the information, but I no longer worry about that as the electronics are much more reliable now.
This solar activity report shows you how bad things were. Yes, I know some of you have probably seen worse, but for me this is pretty bad. I could only work about 20 CW contacts in almost 2 hours, I would normally be able to work over 100 in the same time frame for a point of reference.
When I took the time to check the space weather, I found the screen shot above and then realized why there wasn’t anyone on the bands…they were there, I just couldn’t hear them. So I plugged along and with short band openings I was able to work a little over 20 stations. This was still fun and relaxing since I didn’t have anywhere I had to be and I could take as long as I wanted to play radio today. I got to thinking about how POTA will drive me to stress if I let it. POTA wants me to get the activation as quickly as possible so that I can have the security of knowing the activation is “valid” even though there is no tangible reward for securing it. This is all psychological in nature only. There are not even any tangible rewards at all, not even paper certificates, only PDFs that you can download and print if you want. So why am I so driven to get that first 10 QSOs in the log? I really don’t know, but I know that I am driven… strange isn’t it?
Once I had cleared the band of contacts and started to get a little hungry, I decided to break down the radio set and take a look at the two information plaques that were stationed at this location. It is always interesting to me to see what happened in the place I am at in the past. I have always loved history for some reason. The older Iget the more I like it too…lol. These two plaques describe military actions from both armies and how they interacted at this location. We need to remember the history so we don’t end up repeating it…
So there you have it, a trip to a park, some terrible band conditions and what I did to learn something about my antenna that I didn’t know before. Hope you enjoyed this little adventure and I will see you soon.
73
WK4DS - David