[ICOM] Icom IC-761

[Frank A. Ellis]

Sounds more like the PLL is unlocked. The frequency displayed on the digital display is simply the "commanded" frequency from the digital Logic Unit to the PLL. The PLL is not following this frequency as it is unlocked. Your post seems to imply that the behavior you describe is evident on all bands. For this to be, all (4) trimmers in the PLL would have to failed simultaneously, which is doubtful. If you take a couple voltage measurements around the PLL you will probably locate the problem quickly. It may be the PLL regulator, which is a very common problem. A service manual will help you greatly locating a few key test points as well as the PLL alignment procedure. BFO problems are always mode-specific, e.g LSB, USB, CW/RTTY. Keep that in mind while troubleshooting.

Good Luck!

73 Frank W3UHF



On Feb 3, 2011, at 1:46 PM, jeff partington wrote:

> change the bfo/vfo caps
> 
> --- On Thu, 2/3/11, TVComlGuy at aol.com <TVComlGuy at aol.com> wrote:
> 
> 
> From: TVComlGuy at aol.com <TVComlGuy at aol.com>
> Subject: [ICOM] Icom IC-761
> To: icom at mailman.qth.net
> Date: Thursday, February 3, 2011, 12:57 PM
> 
> 
> 
> Good morning to the group,
> 
> I'm new to the list and I hope someone can help me out with my  IC-761.  
> The VFO's seem to work fine, at least they give a proper readout  when tuned, 
> but the transmitter transmits at anywhere from 8 to 13 mc and the  receiver 
> receives at about 15 mc no matter where the VFO is set.  Obviously  the 
> VFO's are not talking to the rest of the radio.  Any suggestions would  be 
> appreciated.
> 
> 73//Ron, KB0WAR
> 
> 
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> 
> ----
> Your Moderator: Dick Flanagan K7VC: icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
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73, Frank A. Ellis, W3UHF