[Icom] Strange IC-765 40 meter problem

[Colin]

Hi Joe.

I had a not too dissimilar problem yesterday. I found (on 160) that if I
keyed the TX (IC-746) with a 5 watts drive level, the noise level on the RX
dropped. At full power it restored the normal noise level. Also running at
the 5 watt power level I was slightly distorted on TX (local station
reports). I took the ATU apart, I took my vertical apart in the garden!!
Nothing found. Eventually I removed a 90 degree 259/239 Elbow connector I
had in the shack AND THAT WAS IT! Obviously there was something in that
connector that was a bit "iffy". I had only installed it a week or two
before.

I'm only telling you this as trouble sometimes emanates from the least
suspect sources. I would be interested to see what you find!

73, Colin GW3WSU

gw3wsu@ntlworld.com

----- Original Message -----
From: "Joe Stepansky" <joe@microserve.net>
To: <icom@mailman.qth.net>
Sent: Sunday, July 28, 2002 11:43 AM
Subject: [Icom] Strange IC-765 40 meter problem


For brief background, I began noticing something interesting with my
IC-765's performance on 40 meters earlier this year.  The receive level
would occasionally reduce considerably and suddenly (i.e. one second the
band sounds normal, the next it's severely attenuated).  After hitting the
keyer, even briefly, everything returned to normal.  I noticed this
happened more in windy conditions than not, so assumed it was my 40 meter
beam.  Also noticed that sometimes the SWR would go up to 3:1, then back to
a more normal 1.4:1.

Decided to replace the balun and coax on the beam.  Also checked everything
else out while we were up there.  All looked fine.  Came back down, fired
things up, had a 1.2:1 SWR.  Stations sounded fine.  Then the receive
problem kicked in again, and the SWR is now > 3:1!!

Is it possible this is something with the 765??  Has anyone seen or heard
of this happening?  It's so bad that even the antenna tuner won't knock the
SWR down.  I don't have another rig to test it with, so now I'm
stumped.  But we've replaced virtually everything that can be replaced on
the 40 meter beam, so I'm now out of ideas.

Any suggestions will be more than welcome.

73, Joe KQ3F