Why not use a DPDT relay as a bypass... This would allow the antenna side to be shorted to ground and the preamp input to be terminated into 50 or 75 ohms via a resistor, or in the "other" position the preamp would be connected to the antenna. Essentially the relay would be wired the same way as an in/out setup to switch an attenuator in/out of the signal path.
Just a thought... -Bill KB8WYP > Clarification: Actually what I had in mind was to place the short at > the input of the preamp. I want the preamp protected too. My only > concern is the preamp might want to oscillate with a short on its > input. I don't know whether these low frequency, medium gain preamps > are prone to that or whether it would harm anything if they did > oscillate. The 25+ dB gain, very low noise figure VHF/UHF preamps I > am more used to can get pretty squirrelly with something other than > 50 ohms on the input. > > 73, > Paul N1BUG > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
