160 meter page
|Photo of matching system.
(Click for large image w/text)
|Diagram of system|
This is how I am getting onto 160! The system shorts both sides of the G5RV's twinlead together, making it a large "T". The coils and cap work together as a tuned RF transformer to match the impedance to the radio. (My 80-10 antenna tuner has an "Alternate" jack, which bypasses the internal tuner. This allows use of an external tuner and an alternate antenna. It is worked against a water pipe ground. All of the plumbing and the baseboard heater system in the house become a "counterpoise". While this is not extremely efficient, it DOES get a somewhat useful signal onto the airwaves. If you hear me on 160, this is what you have heard! :)
The capacitor tunes the 2" coil to resonate with the antenna. The alligator clip is moved on the large coil to give a spot where the SWR is minimal. Touch-up the tuning capacitor to "zero" the SWR, and you're ready to go! Tuning is fairly sharp, so I can only move a few Khz before needing to touch it up. Once the big alligator clip is set, the tuning cap is all that needs adjustment.