[VHFcontesting] pre-amp hookup help

[Chris Lumens]

Hey, everyone.  I've been thinking about this for some time but haven't
gotten it figured out.  It's only mildly off topic for this group.

The extremely short story is that I want to add a 70cm mast mount preamp
for my home satellite setup.  That doesn't seem too hard - sequencers,
bias tees, etc. - but of course it's the details that make it difficult.

I have two antennas and two radios.  The radios are an FT-818 and an
IC-7000.  Several years ago while roving, I broke the headphone jack on
my IC-7000 and according to Icom, fixing it requires replacing the whole
face place, which is expensive.

Therefore, instead of what most people do, I have a TX radio and and RX
radio.  Some sats have a 2m downlink/70cm uplink, and some have the
reverse so that means I have to switch the cables back and forth between
the two radios.

That is what makes adding a pre-amp hard, as far as I can tell.  It
could potentially be hooked up to either radio and that could change
several times in a given day.  That means I don't want to have a manual
step involved, because one day I will forget to do it and that'll blow
up the pre-amp.

I could fix this by buying a replacement face plate ($), a second FT-818
($$), or an IC-9700 ($$$) but I really don't want another radio right
now.  If I could get the pre-amp out of the way by simply sending a
signal down the coax, I could probably fix this by also buying a 2m
pre-amp, ensuring there's always a pre-amp that needs to get out of the
way.

My other concern is: I'm not sure a sequencer alone is gonna fix my
problems.  When I key up the mic, there will be RF present on the coax
before the sequencer has gotten time to act.  I don't believe the
IC-7000 has any sort of TX inhibit, so I don't know how to tell the
radio to not actually transmit until things have switched over.

Any clever ideas for dealing with these two problems?  Thanks!

-- 
Chris Lumens - KG6CIH
Hike * MTB * XC Ski * Haskell
Research - Experimentation - Testing - More Testing