[-] [ICOM] 746 pro auto tuner problems

[Paul Playford]

OK, you seem to have eliminated the antenna as the problem.

Now confirm you really have power output from the radio using an external 
wattmeter with and without the tuner and ensure you can control the output 
power with the RF POWER control.

If you have rf output but cannot control the level try operating the receive 
attenuator and test again.

If the problem goes away with the attenuater operated you have the 
(in)famous IC151 oscillation problem.  This oscillation can occur at wierd 
frequencies and drive your antenna tuner nuts.

And I would try a cpu reset.

If still no joy then I suggest you obtain a service manual and start by 
checking the detector diodes in the antenna tuner.

de Paul, W8AEF

ZF2JL/ZF2TA  FO8DX/FO8PLA  8Q7AA  XZ0A  VU7RG




----- Original Message ----- 
From: "Ed Yeary" <w4tey at bellsouth.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Tuesday, September 11, 2007 2:08 AM
Subject: Re: [-] [ICOM] 746 pro auto tuner problems


> Ok when tuned into a dummy load no joy there either. It doesn't even begin 
> to tune. I switched antennas and it still wouldn't tune. Tunes 6 fine 
> (apparently) but won't do it on the rest of the hf bands and I have tried 
> them all. It starts to tune with the click click but then the swr shoots 
> high and the tuner kicks out in all trials.
> Ed  W4TEY