Recently during operation at a warmer location in Florida I went against my personal knowledge and experience while deploying my Buddipole antenna. I have used this antenna many times so I am quite familiar with the performance and configurations of this antenna. My available space consists of a patio in a small yard so the Buddipole antenna used temporarily during my stays there is my antenna of choice. The antenna consists of a T center component, 2 arms that screw into the T in either a dipole or an L configuration. I prefer the L configuration as this makes the antenna a Vertical resulting in better performance without the need to be high above the ground. The antenna also includes a tapped coil on each element and finally, telescoping whips. Depending upon the frequency/band of desired operation, coil tap and telescoping whip length, adjustment is required. Printed instructions included with the antenna specify the coil taps and whip lengths to be used per band of operation for deployment as a dipole. As we all should know, height above ground affects antenna tuning characteristics making it necessary to do some adjustments along with the “L” configuration vs. dipole configuration. My rig is a Yaesu FT100D along with my trusty MFJ antenna tuner. Yes, if the antenna is adjusted correctly the tuner shouldn’t be needed. Anyways, I connected the coax after setting up the antenna and hooked up my NanoVNAA to the tuner and tuned it to a low swr reading. So far so good I thought. Next I connected the radio. I had the antenna adjusted for 20 meters. Heard some activity on cw so tried calling a few cq’s. No response so tried again. Nothing heard so I called cq a few more times with no luck. Must be poor band conditions I assumed. Decided to check the reverse beacon network on the internet. Searching for my callsign resulted in a couple of spots posted. Good, I was getting out but only a couple of spots so band conditions must not be too good. The spots were also showing weak signal levels so must be poor band conditions. More CQ’s with no responses and no additional spots on the network. Enough of my time spent with the radio for the day and darkness will be shutting down 20 meters for the day anyways so enough for now and time to prepare for dinner. The next day I decided to try my luck again. The band should be open now so more CQ’s. Still no luck and no spots from beacons. Maybe the band so I switched to 15 meters. Adjusted the tuner for a low swr on 15 meters and send some CQ’s. No responses and nothing showing up in the reverse beacon spots. What in the world is going on. Just my luck to have such poor propagation. More time trying to raise a response but no such luck. What is wrong. I hear some activity and the radio seems happy with the antenna matching ok. Oh well the weather is great, Sunny and 80. So I guess I’ll go outside and check the antenna connections again. Everything is tight. Back to the radio and everything appears to be in order. Another hour half of an hour goes by and no contacts and no spots showing up. Time for a break and time to check the stock market. At least something is showing success today. While looking at the market it strikes me that I never checked the antenna tuning without the tuner in play so the next day I decided to do things the right way. Rechecked the antenna without the tuner in play. The NanoVNA shows resonance at around 25 MHz so added a couple of coil turns and fine tuned the whip lengths to bring it into a 21 MHz range. A little more adjusting brings resonance and SWR to below 2:1. Hook it back up to the tuner and adjust to 1:1. Hooked it back up to the radio and make a final adjustment to 1:1 again. Now for the moment of truth. Call some CQs and see many spots with my callsign on the reverse beacon network with good snr numbers from many of the stations. And now I actually start making some contacts. Things are good again! I should know better than trying to rely on the tuner. After all some of my professional career was involved with antenna design and characterization. A dummy load looks good to the VNA but does not put the power at the antenna where it needs to be. Taking shortcuts can waste time in the long run. The rest of my stay in Florida resulted in numerous contacts around the world with 60 watts and a Buddipole antenna.
Next time I hope to not make the same mistake.
KC0INP