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From: mch <mch@...>

I wrote (originally):
One more quick thing on a Mitrek. I have one on 440 I duplexed that is
deaf as a stump until the TX comes up. Then, the sensitivity is great!
As soon as the tail drops, it goes back to being deaf. Here's the
kicker: it ONLY does it when connected to the duplexer. It works
flawless if I connect the RX to an IFR to test the sensitivity.

Then Joe Orrico WB6HRO wrote:

Sounds the the diode that must be removed to keep the voltage on the
rx is not correct, would suspect that rx voltage is not right during
normal rx function.

But how would a receiver connected to an IFR differ in voltage from a
receiver connected to a duplexer? In case I gave the wrong impression,
the unit is still at the repeater site - the only change is that the RX
antenna was 'pulled' from the duplexer and plugged into the IFR. The TX
is still connected to the duplexer, and the power (both TX and supply)
is exactly the same. It's as if the duplexer is severely mis-tuned. And
since I didn't mention this either, it works flawless on a Mastr-II - RX
sensitivity is great both direct and through the duplexer, so the
duplexer is tuned correctly. (In fact, it has never been changed from
the factory)

I will check the voltages, though. The only problem is that the
troubleshooting must be done at the repeater site. The duplexer is the
one in normal use. This is almost like reverse desense - perhaps there
was a slight spur when the TX was inactive that severely desensed the
RX??? I didn't check that.

Thanks for the response,
Joe, KR3P

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