[Icom] IC-746 built-in Antenna Tuner problems

Tue, 17 Sep 2002 10:46:07 -0400

Al,

I had something similar go wrong with my 756 PRO.  My situation was on all
bands the antenna tuner would tune to 1:1, but as I would speak into the mic
the SWR would creep up to over 2:1. Oddly enough, this would not happen in a
constant carrier mode such as RTTY or in CW. Only SSB.

I called Icom and the tech told me to send the rig in immediately. So they
were aware of the problem.  In any event, it appeared Icom changed the
tolerances for several caps in the tuner from the original specs.  This
affected a limited number of 756 PROs.  All in all, a $0.10 part cost Icom
probably about $150 in shipping and labor to repair the rig.

Again, this may be different issue but I would give Icom a ring...

Harry WE1X
----- Original Message -----
From: "WB8FEQ at Home" <[email protected]>
To: <[email protected]>
Sent: Tuesday, September 17, 2002 9:43 AM
Subject: [Icom] IC-746 built-in Antenna Tuner problems

> Hi all.
>
> My IC-746 has been working great for over 3 years but over the last couple
> of weeks I noticed that the antenna tuner is not locking in propperly.  At
> first I thought it was on all bands but further investigation I find it is
> primarily on ten meters.  I even connected a good 50 ohm dummy load with
> three different jumpers.  It can never find a good match (thought the on
> screen SWR readings do go through a good SWR and back to infinity.  With
the
> tuner out of line the dummy load shows a 1.1:1 reading.  The other bands I
> normally opearte on (75, 40, 20 and 6 meters) seems to be funtioning
> correctly with their respective antennas.  I was wondering if anyone has
> encountered this before and if there is any known "normal" that would be
> seen as the cause of this.   Aany other thoughts/suggestions before I give
> up and send it to a service center (which based on the current size of
> components and my less than perfect eyes may happen even if I find a
> defective component) would be appriciated.
>
> Thanks in advance - Al WB8FEQ
>
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