Q1) Would a simple relay disconnecting the vertical wire at the TX antenna feedpoint be good for detuning TX antenna? (I am using a piece of wire attached to 18m Spidermast for the vertical section)
Sounds like a robust relay, just above the feed-point would de-tune the L rather nicely. At least that was my thought. Probably simpler and more straightforward than trying to detune it in the shack.
Short of expensive fast vacuum relays, what sort of readily available T/R (not QSK) relays handle QRO power at non-50-ohm points? If it was purely 50 ohms, I wouldn't feel bad using a big ice cube re
Well, it sounded like Thomas wanted to de-tune the L, so it wouldn't interfere with his receive antenna when receiving. Assuming that he's only using the L for 160, he would be switching at a high-cu
De-tuning an electric fence is something I have thought about (I have some here). Two possible ideas (these are not proven - so I won't say "solutions"). If the fence doesn't need to be active while
Tim The issue with the relay at the antenna is the time to close the contacts and avoid RF hot switch. I'm using a Jennings RJ1A-26S for years, just 4-6 milliseconds to close. Or you can use a sequen
Tom it is a 1/4 wave L, with the vertical section dictated by a 18m Spidermast telescopic rod. A poor man's version of L worked satisfactory for me in 2010 VK9LL operation, without any tuner at the b
Well, Tomas If you are comfortable using Smith Charts, you could work out some reactance for any length of feedline to detune the antenna. Other than your 1/2 wave approach, another approach would be
If the antenna is close to a quarter wave, one rather easy termination is t make the feedline either a shorted quarter-wave or an open half-wave of transmission line. A halfwave of RG8/RG213 for 160M
FYI, I see on the Max Gain site (and local to me) that he is out of the RJ1A series of relays. tnx Mike / W5JR Alpharetta GA The issue with the relay at the antenna is the time to close the contacts
Yes. You might solve that by using PTT from the radio, which for most modern rigs, occurs 8-10 msec before RF, and in some rigs the delay is adjustable (K3, FT1000-series are some I know of). 73, Jim
<<< A poor man's version of L worked satisfactory for me in 2010 VK9LL operation, without any tuner at the base, the bottom terminal of the vertical wire directly connected to the center conductor of
Tom appreciate sharing your thoughts. I see there are different ways. Considering the TX Antenna will most likely be half wave feed away from the radio, the most appealing to me at the moment seems t
Detuning a wire inverted L seems simple and straightforward. Detuning an electric fence is another matter entirely!! :-) 73, Charlie, K4OTV --Original Message-- From: Topband [mailto:topband-bounces@