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
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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