[Icom] 706 MKII keying & using amp???

[W3UIO]

--- Adam Farson <farson@shaw.ca> wrote:
> Hi Larry,
> 
> The HSEND and VSEND lines are bi-directional. When
> you key the IC-706
> transmitter via the mic or key, the line extends a
> ground. When you apply an
> external ground to the line, the IC-706 switches
> from receive to transmit.
> 
> Is it possible that when the amp SEND key is
> depressed, the amp extends a
> ground on its keying line with sufficiently low
> source resistance to key the
> IC-706? This would account for the loss of receive.
> If this is the case, you
> should be able to block the sneak path with a diode
> in the keying line
> (cathode towards IC-706).
> 
I put a 1N4004 in the input circuit of the buffer. It
still keys the amp, but the receive is still cut off
when the Alpha button is engaged. I suspect that
circuit doesn't cut it with the 706, as it is an ICOM
circuit for rigs with the keying relay.

I'm tempted to try it with no buffer. Or I could just
refrain from using the 706 with an amp until my 756
ProII arrives in a couple of weeks. They were out of
stock.

You should all be proud of me for moving from the Omni
VI Plus to the ProII. :-)

=====
Larry, W3UIO

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