After blowing up the antenna transfer board on my FT990 as a result of a
very close lightning strike, I built up a relay switcher which (a) grounds
the Beverage RX feed from the remote switch box when power is turned off
and likewise grounds the RX-only input jack on the radio (b) grounds the
RX-only jack and the Beverage line feed during TX. The contact spacing on
the radio's
RX-only changeover relay is very small...the relays I am using have 10A
contacts with wide spacing. I use a "Y" jack to the amplifier's PTT line
for control.
Nothing difficult here...just a couple of relays and a selector switch.
Perhaps a couple of diodes would be a good idea to deal with any spikes
which jump the relay contacts (but then...if they can do that, diodes would
probably be ineffective and I would be buying a new radio!!)
Bill, VE3NH
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