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

[J. Forster]

Hi Joe,

I've never even seen one. I was talking about it from a strictly ME point
of view.

It sounds like they might be repairable, either with a clamp fixture and
solder or superglue.

Also, if you have access to a small lathe, you could get some brass hex
stock and drill it and make replacement pieces to press on, after removing
the existing piece.

FWIW,

-John

================


> Hello John,from Joe in Okla..
> After looking closely at three of the trimmers,they all have a similar
> crack
> running length wise to the shaft..  Do you know of a source for
> replacements..  Joe w5jdy
>
>
>
>
>
> ----- Original Message -----
> From: "J. Forster" <jfor at quik.com>
> To: "jmfranke" <jmfranke at cox.net>
> Cc: <milsurplus at mailman.qth.net>
> Sent: Friday, May 13, 2011 11:16 AM
> Subject: Re: [Milsurplus] [Boatanchors] BC-348 E-M-P
>
>
>> That tells you exactly what the problem is. The tolerances were out for
>> the press fit, causing an excessive hoop stress in the hex nut. A worn
>> or
>> reground drill bit on the screw machine is likely the root cause.
>> It eventually fractured.
>>
>> -John
>>
>> ===============
>>
>>
>> > In all cases I have found the capacitors to be free of corrosion and
>> the
>> > exposed shaft bright and shinny. Examining the hex sleeves, I have
>> > typically
>> > found a single hairline crack running parallel to the shaft axis. Once
> the
>> > hex nut loosens, the three prong spring moves the rotor until the
>> plates
>> > meet and short with the stators.
>> >
>> > John  WA4WDL
>> >
>> > --------------------------------------------------
>> > From: "John Hutchins" <jphutch60bj at gmail.com>
>> > Sent: Friday, May 13, 2011 8:52 AM
>> > To: <milsurplus at mailman.qth.net>
>> > Subject: Re: [Milsurplus] [Boatanchors] BC-348 E-M-P
>> >
>> >> 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
>> >
>> >
>> >
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