Dave, That situation is dealt with routinely by VHF folks with mast mounted preamps. Using a coax relay to connect the amplifier to the antenna and a second relay to connect the preamp to a 50 ohm load will usually provide adequate isolation.
73, Don W3FPR On 4/22/2012 4:03 PM, David Herring wrote: > Hi Everyone, > > Yes, this is off-topic a bit, but I know there are some of you here who will > be able to get me going in the right direction. > > I have a PixelSatRadio RF Pro 1A receive-only moebius loop antenna. It is > being used with a Kenwood TS-440S that does not have the provisions for a > receive antenna like the K3 does. In order to make sure one doesn't fry the > antenna's pre-amp, I need a fool-proof way to ensure that no one ever > accidentally sends RF down the coax to that antenna. > > I have thought about maybe some kind of a PTT enabled antenna switch. > > I have thought about some kind black box with a circuit one could build that > would act as a gatekeeper to allow RF in from the antenna but block any going > out. > > I have searched the 'net and have not yet found anything along those lines > that I could implement. > > So my question to you is, can anyone here recommend such a switch or such a > black box circuit? Or maybe propose something else that I'm not even > thinking of? Any ideas, suggestions, recommendations? > > > > I need this to be on-the-cheap and I'm not opposed to homebrewing something > here, though I only have modest-at-best skills in homebrewing. > > > Many many thanks, > > Dave, AH6TD > > > I now return this reflector to normal programming, already in progress. ;-) > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
