[Swan] Sensitivity and meter on 500

[Jeff]

Thanks Steve!

C202 has been replaced by discrete caps under the chassis, so that 
should rule out one.  I'll replace the 12BE6 as you suggest.

I've also removed the grid, plate and load variables and sent them to 
the dishwasher.  I'm getting intermittent faults with them, so might be 
another variable.


Jeff



On 7/3/2017 2:29 PM, Steve Sutfin wrote:
> Hi Jeff,
>  This is in case my response didn't get thru the 1st time.
> Both the 12BE6 2nd IF and the C202 CanCap have an effect on the 
> S-Meter AND the AGC system which could result in low receiver 
> sensitivity. I can see that happening with the 12BE6 after warm up. 
> Something to look into.
> 73,
> Steve k7dna
>
> On Jul 3, 2017, at 7:11 AM, Jeff wrote:
>
>> Hi all -
>>
>> Seeking some advice on a 500.  This seems temperature related, and 
>> I'm having a hard time tracking it down.  I picked up a basket case, 
>> and have been slowly rebuilding it.  I have it transmitting and 
>> receiving OK now, but only when it's cold.
>>
>> From a cold start, the s-meter and receive function works as 
>> expected, with good meter swings on signal peaks.  However, as the 
>> rig heats up, the s-meter deflects less and less until it basically 
>> remains stationary.  I also begin to lose receive sensitivity.  
>> Compressed air blown at spots underneath the chassis doesn't seem t 
>> have any effect, nor does air applied to the air variables.  It 
>> just... dies out.
>>
>> Short of just starting to shotgun everything, does anyone have any 
>> suggestions on where to start looking?
>>
>> Thanks...
>>
>> Jeff
>>
>> WB3JIH
>>
>>
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