[Icom] IC-765 tuner problem

Thu, 09 Jan 2003 17:52:21 -0700

Hi,
Worth going thru the tuner alignment but if you replace those two adj. 
pots with multi-turn ones
it'll be much easier to adjust.  Pots in there are too jumpy. Do you 
have a  noise bridge or dip meter?
Handy items when working on antennas. What is your new antenna?
73,
Tony, VE6CGX

Floyd Sense wrote:

>Check out the 765 tuner adjustment procedure under Icom 765 at this site:
>http://www.mods.dk/
>
>K8AC
>Floyd Sense in Angier, NC
>----- Original Message -----
>From: <[email protected]>
>To: <[email protected]>
>Sent: Thursday, January 09, 2003 4:13 PM
>Subject: [Icom] IC-765 tuner problem
>
>
>  
>
>>Hello,
>>
>>I've noticed that my IC-765 seems to have a problem with its tuner.
>>I was trying a new antenna and noticed that the tuner seemed to
>>stop at an SWR greater than 3:1 (on the 765's meter) with the
>>WAIT LED off and the TUNER LED on indicating a satisfactory match!
>>I switched to a dummy load and the same thing happened.
>>I thought that perhaps one of the motors had jammed so I removed
>>the cover and discovered that both capacitor gears were turning
>>but C17's gear (on the right when viewed from the front of rig)
>>was moving very slowly. So slowly that if I waited 45 seconds
>>it would eventually match the dummy load. No motor noise was
>>evident, so I had assumed that the tuner really had stopped
>>as the LED's indicated. After that I tried switching bands and
>>found that both motors turned at about the same speed. I went
>>back to my old antenna and found that everything seemed to work
>>properly. However, if I switch to the new antenna I can start
>>the whole problem sequence over again!
>>
>>So it seems that the tuner gets into a state where some of it's
>>logic thinks it got a match (even though it doesn't) and C17
>>turns so slowly that it's imperceptible unless directly viewed.
>>That state persists even after a dummy load is connected.
>>
>>The main external symptoms are the WAIT LED going off when the
>>SWR meter still indicates an SWR greater than 3:1. At this
>>point the tuner motor noise stops. The SWR then slowly drops
>>over a period of about 30 to 45 seconds.
>>
>>Before I start taking things apart and adjusting things (i.e.
>>breaking things) has anyone else encountered this problem or
>>does anyone have any suggestions?
>>
>>Thanks and 73,
>>
>>Don
>>
>>ve3hur
>>[email protected]
>>----
>>Your Moderator: Dick Flanagan W6OLD, [email protected]
>>Icom Users Net: Sundays, 1700Z, 14.315 MHz
>>Icom FAQ: http://www.qsl.net/icom/
>>
>>    
>>
>
>
>----
>Your Moderator: Dick Flanagan W6OLD, [email protected]
>Icom Users Net: Sundays, 1700Z, 14.315 MHz
>Icom FAQ: http://www.qsl.net/icom/
>
>  
>

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