As I write this, I am currently sitting in my hotel room at East Hill Farm. East Hill Farm is a working farm and a family resort in Troy, NH. It is school break, and I am with my family having a blast. At the farm, there are many ways to entertain yourself. You can spend time in the barn, sit by the fire, eat, or just relax. I love spending time in the barn doing different chores and eating (!). On this trip, I decided that I’d play some radio too. Last year when we were here, I had just received my general class ticket, but really didn’t understand the general concepts of radio yet.
Last year, my weakness was the performance of my antenna. I was new to the hobby and understood very little about antenna theory. I used a 4 foot tall vertical on a speaker stand. It had 1:1 SWR on every band I tested it on, and I thought it radiated well. In other words, it was a REALLY good dummy load (with an absurd amount of common mode current)! Since then, that antenna has been destroyed, and I try to laugh at myself for my own stupidity.
Both last year and this year, I set up my station on an extra bed in our hotel room, which has worked well, despite its original design. I use an MFJ manual tuner and my trusty Yaesu FT-450D.
Anywho0, this year I knew I could improve my set-up, and it was not hard to set up better than last year! A dipole 1 ft off the ground would be 20 db louder! I could not assemble a traditional dipole and vertical because the hotel room is not close to any trees, and we do not have a large deck to spread out ground radials, etc. on. However, I had been eyeing the 31 ft Jackite fishing pole for a long time, and decided this project would be a good excuse to buy one. I knew whatever I built or used was going to be a compromise. That is a fact of hotel room operation, BUT I WASN’T GOING TO BE RIPPED OFF FROM BUYING JUNK! My plan was to wind a 9:1 UNUN to use with a long wire. The UNUN would be used to convert the impedance to something easier to match by the radio, and use up at least 3db of my power in heat. Going into the build, I knew the antenna was going to be perfect. Because the antenna is fed at the end, their is a crazy amount of common mode on the feed line. The shield acts as the other half of the antenna. I decided the project was worth a shot and Ebay let me land a pole for 70 bucks.
At this point, I had the pole, now for the antennas. I found the right ferrite in a drawer, and was able to wind it in around 15 minutes. I installed a few banana plugs on a NEMA box, and called it a day. I know this antenna configuration has also been used by my friend, NT1K, and he blogged a lot about building the UNUN, so not going to try to here, because he did a REALLY good job! I built the UNUN a few days before going on vacation. I decided to try it with a few different lengths of wire to see how it performed. Since the pole had not arrived yet, I hauled the wire up into the trees at my house to give it a test. The performance was OK. It was down a few DB on TX and RX relative to my vertical, but I was pleased. Similarly it was noisier too. I think that is due to the common mode, and the noise from my house. It loaded up on 40/30/20/17/15/12/10. After trying different wire lengths, I decided on using a plain old 30ft piece of THHN.
When I arrived at the farm, I was a little nervous about the antenna and the configuration I planned on using, because I had not had time to test it with the pole. At the hotel, set-up went very quick, despite the -20°F degree temperature. I was on the air in less than 10 minutes. Performance is good, considering the antenna. Please don’t whine at me about using an end fed, hey it works! Although my antenna is a big compromise, I have had a fun time operating /P from the hotel and have been able to work DX. Fun is the most important part of ham radio, right?