27
Ham Radio – It Shouldn’t Work!
Filed Under (antennas) by Administrator on 27-02-2010
I had a dentist appointment in Green Bay, Wisconsin recently and the 30 mile or so drive from Appleton, Wisconsin gave me time to do some HF work with my mobile HF radio. Running just 100 watts into a less than sturdily mounted “ham stick” antenna on 20 meters I made an outstanding contact with a ham radio base station in France! For some time after that I nearly gloated to myself about how lucky I was to be able to enjoy this hobby and how everything was working so well. Bad move!
A couple of weeks later I was driving home from work and flipped from 2 meters over to 20 meters. The band was surprisingly quiet! Was it due to low solar activity? AND – there was surprisingly little traffic on the band. A few people, but not many. Hmmm… I started to get a bad feeling… I went to an open part of the band and made a quick transmission with my call sign with one eye on the SWR indicator on the radio’s display mounted on my dash. There it was – a flashing “SWR” – I probably had an antenna problem.
Well, I had mounted the antenna on the trunk in a snow storm and tuned it when it was around zero degrees Fahrenheit… Not a time that LockTite epoxy would work on the mounting set screws. Surely the mount had lost it’s ground connection. So I popped the trunk and checked it out – good tight connections… hmmm…
When I closed the trunk I noticed – the tunable radiating element (the adjustable length whip at the top of the antenna) had become a LOT shorter. A closer inspection showed that the two set screws that held the antenna to the tuned length at the top of the antenna had been shaken or vibrated out. Made sense. That antenna is quite long and whips around in the wind at highway speeds quite a bit. So I presumed I would be in HF withdrawal until I could find someone with an expensive antenna analyzer that could help me re-tune the antenna.
Ahh but I was wrong! On another drive back from Green Bay, Wisconsin I decided to just listen on 20 meters. Surely I would hear nothing, but I was bored… To my surprise I listened to some quite strong and clear traffic between Georgia, USA and Vancouver, Canada during the 2010 Winter Olympics! To my mind – it shouldn’t have worked, but it did… It was quite a surprise. And it gave me cause to check other bands, including shortwave bands, to see what else I was missing!
As of this post, I still have not found the correct size replacement set screws for the antenna… grumble grumble… The good news is that the air temps are warming and it will soon be warm enough to cement the set screws in place once I do acquire them.
Stay radio active!
Jon Kreski, AB9NN

