I once was in need of a random-wire tuner and just didn’t feel like buying one. I knew I would rarely use it… so I built one from junk parts. I had the air variable capacitor and some SO-239 connectors. For the box I just used a metal watch case I found at Good Will for $.50. By the way, Good Will is an awesome place to get metal cases. The coil is just a wrap of 22g magnet wire around a 35mm film canister. The switch is a 12 position rotary contact switch I purchased from a local electronics place. Does it work… YEP! It can tune most random lengths of wire from from 40M to 10M. I have a video of the one time I used it while in Hawaii (Click To Watch on YouTube).
AD7C
Amateur Radio Blog, Log, and Outdoor Adventures
nice set up,any losses with the coil ,and does it get hot
I only use it with QRZ so there is no worry about heat. I can’t comment on any losses with the coil as I never even attempted to try any measurements. However, it does work seemingly well!
Rich
AD7C
Do you have a schematic? I wanted to make a swl receive only antenna tuner – this looks like it would work right.
Thank you! 73′s
Bill
No schematic readily available. It’s just a hand-wound coil on a plastic pill-bottle and a var-cap. However, I referenced this site: http://www.qsl.net/wb3gck/tuner.htm
Rich
Hey nice tuner. Did you use all 12 positions on the rotary switch?