[1000mp] Bad Antenna Relay?

Tue, 14 Oct 2003 22:18:20 -0600

I haven't seen this problem with my MP or my Mk V, but I use them heavily
only on FD, so maybe the infrequent use has helped. However, I do have a
suggestion. I work in the electronics industry, and I once designed an
instrument that had a lot of multiplexer relays in it (Tip, if you're
reading this - it was the ASRU in the 3060!). These relays could, over time,
get dirty and foul up the measurements. We eventually wrote a program that
we gave customers that cycled the relays a bunch of times (hundreds of
times, rapidly) as a way of cleaning them. Since the FT-1000 is a
programmable rig, you could easily write a simple VB program that would
cycle the A/B/Rx relay(s). See my article in Feb, 2002 QST on The Return of
the Slide Rule Dial for a sample VB program that shows how to communicate
with the rig. I don't have time to write it, but perhaps someone else in
this group does. It would be pretty simple. (Also remember that relays have
a finite number of cycles, usually around 10 million, so you don't want to
overdo it either!)

Brian, W0DZ

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Earl W Cunningham
Sent: Tuesday, October 14, 2003 7:16 PM
To: [email protected]
Subject: Re: [1000mp] Bad Antenna Relay?

Barry, N1EU wrote:

"So yet again, I offer up my contrary theory that it has nothing to do
with relays but is a problem with the way the MP controls rf/if gain.  As
I've noticed several times on my MP, the receiver can be deaf and then
slowly the gain comes back up over the course of several seconds while
I'm just listening without keying the rig or touching anything."
==========
When my MP had the intermittent "deaf receiver" problem, it never had the
gain slowy return to normal.  The gain would never come back until I
re-keyed the rig momentarily or until I toggled the A/B or RX front panel
antenna selector pushbutton.  It was always quite evident that the
problem was an  intermittent relay contact connection in one of the
switching relays in the receive signal path.

The problem occurred less and less frequently as time went on.  I haven't
experienced the problem since the radio was about two years old (bought
new in 1998).  I assume that, after hundreds of tx/rx cycles, the
offending relay contacts eventually burnished themselves clean and
therefore the problem went away.

73, de Earl, K6SE
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