[Premium-Rx] WJ 8617 Synthesizer Problem (?)

[David Schofield]

Hi all,

Sorry. I should have read all of the post before replying. I can now see 
that Rye already has the manual.
Sorry again for wasting resource.

Dave.S.


David Schofield wrote:
> Hi Rye,
>
> I think this may be some kind of "stock fault". My receiver behaves 
> exactly the same as you describe whilst cold. As soon as it reaches 
> operating temperature after being on for 10 min or so everything is OK. 
> Have you tried letting yours warm up and seeing if it returns to normal?
> With this sort of fault I would strongly suspect capacitor failure 
> either within the PSU or the synthesizer itself.
> I have a copy of the technical manual which can be obtained from 
> http://www.vintagemanuals.com/ do a search for the 8618B essentially the 
> same Rx.
> I can scan small sections for you if it will help you locate the fault.
> I am also going to take a look at mine in the near future so will let 
> you know what I find. So far I have been lazy and just left it on to 
> warm up before use but would like to get to the bottom of it.
>
> Cheers,
> Dave.S.
>
>
> Rye Gewalt wrote:
>   
>> I'm wondering if anyone on the list had any experience with the synthesizer
>> in the Watkins Johnson WJ8617?
>>
>>  
>>
>> I have a lovely B-17 model that has suddenly lost the ability to tune in
>> anything under 1 MHz steps.  The display shows the full frequency and all
>> other functions seem to be working so  suspect that the problem is
>> associated with the second LO --- probably out of lock.  In fact, the radio
>> is kind of 'drifty' in that when I listen to signals at the 1 MHz  steps --
>> I can hear them drifting around as if the VCO is not being disciplined, but
>> is running.
>>
>>  
>>
>> Perhaps one of you have had experience with such a fault or could point me
>> to somebody who might be helpful.  I've got the manual and all (most?) of
>> the extender cards etc. and a pretty good shop but, I'm kind of reluctant to
>> dig into the radio until I've checked with the experts to see if this is a
>> problem that has a known fix methodology.    --- no point in reinventing the
>> wheel and maybe screwing up something else in the process...
>>
>>  
>>
>> Any help would be greatly appreciated.  
>>
>>  
>>
>> In the meantime, I will spend some time checking supply voltages etc.
>>
>>  
>>
>> Rye
>>
>>  
>>
>>  
>>
>>  
>>
>>  
>>
>>  
>>
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>>   
>>     
>
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