[Milsurplus] [Boatanchors] BC-348 E-M-P

[John Hutchins]

Dennis, Joe
"After trouble shooting I found that about 5 or 6 of the 30 or so 
alignment APC trimmer caps located in the Ant,RF,Det and Osc boxes had 
shorted. They had slipped on the shaft someway and shorted the plates 
together."

Slipping shaft - I do wonder how the plates could move;  Could it be 
corrosion buildup, pushing the shaft?
Any how thanks for the detailed analysis,  Something to look for.

Hutch

On 5/13/2011 12:08 AM, mac wrote:
> Bad APCs......   Yep, had a 348 full of those and have heard of other
> instances of the problem.  Don't know if anyone has traced the problem
> back to particular manufacturers/models/contracts etc. or not.  Can't
> help you on the silver mica.
>
> Dennis D.  W7QHO
> Glendale, CA
>
> *************
> On May 12, 2011, at 5:47 PM, Joe Walden wrote:
>
>> Hello members of the various reflectors,from Joe w5jdy in Okla.....
>> I want
>> to share an experience I am having with a BC-348-P receiver.  This
>> radio had
>> been setting in a dry temperature controled environment for about 40
>> years.
>> It was working when it was stored.  Upon reviving the external power
>> supply
>> and connected it to the radio,it didn't play hardly at all.  Some
>> bands were
>> partially dead and others were entirely dead.  After trouble
>> shooting I
>> found that about 5 or 6 of the 30 or so alignment APC trimmer caps
>> located
>> in the Ant,RF,Det and Osc boxes had shorted. They had slipped on the
>> shaft
>> someway and shorted the plates together.  In all the old parts I
>> have I will
>> be able to replace most of the bad ones (I hope) but during removal
>> of one
>> of them the lead broke off of a 50pf mica cap right up next to the
>> case.
>> Too close to repair.  My 2 questions are:   Has anyone else
>> experienced
>> trouble with the trimmer alignment caps in other BC-348?   And can
>> anyone
>> help me with a silver mica 50pf at 400 volts 1%.    Pleas contact me
>> off
>> list at   w5jdy at cox.net    Thanks, Joe
>>
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