[INRAD] Icom band decoders

[K4RO Kirk Pickering]

I've been trying to send this to George and Dave directly,
but there seems to be some kind of problem with an anti-
spam filter rejecting my domain.

I am having two different problems with Top Ten band decoders.

The first problem is that they will not consistently engage
the 160m meter position when decoding an older Icom radio. I 
have encountered this before with other Icom rigs, and it had 
to do with the decoder's break point between 80 and 160 being 
too close to the cross-over point of the analog band voltage 
coming from the rig.  At one time I added a small battery in
series with the band-voltage line to the decoder to bump it 
up by 0.5 volts. That was enough to ensure consistent 160m
operation.  This was a crude kludge, but it worked.  Is there 
a more elegant way to get TT band decoders working with the 
IC-781 and IC-765 series radios?

The second problem started happening a few months ago on one
band decoder only. The symptom is that one band position (80m)
does not go to full high (12V) when NOT selected.  Instead,
7 to 8 volts is present when measured at its corresponding
six-way relay box 80m terminal.  The terminal sinks to ground
(~1V) properly when 80m is selected, but it does not go full 
high (12V) when not selected.  The result is erratic behavior,
with high SWR on all bands and antennas, perhaps from two 
antennas being selected simultaneously.  When I swap out a
different TT band decoder, the problem goes away.

Any insight to either of these problems would be much appreciated.

Thanks,

-Kirk  K4RO