[ARC5] BC-348-Q Capacitor Testing

[DSP3]

Well,  having been through about 15 or so (at least) BC-348 receivers, 
half a dozen being mine, I certainly recommend re-capping all paper and 
sealed capacitors.  I started out using Orange Drops a number of years 
ago but have moved over to the smaller and much less expensive types.  I 
have had no issues, whatever.  I absolutely concur that the modules must 
be removed (fairly easy on all but the J, N, and Q models) and re-done. 
Those rear-panel resistors will go, believe me.  The difference in 
operation after a competent re-cap is, generally, noteworthy.  If you're 
doing the job, don't forget to do the few inside the xtal filter and BFO 
cans and don't leave out the ones hidden behind the front panel access 
door on the J, N, and Q models.  I fully appreciate and applaud those 
who want to keep things as original as possible but, from my personal 
point of view, outward appearance and function trump what's hidden 
inside and below-deck.  Re-functioning the AVC switch for use if an a.c. 
supply is installed is a nice touch.  Either one or two sections of the 
3-section (on J, N, and Q) or 6-section switch (all others) are all 
that's required.

Jeep - K3HVG


On 1/29/2016 9:09 PM, John Hutchins wrote:
> Mark, Sudipta
> Please Note the oil filled cans can be unsolder'ed drained of oil, and 
> re-stuffed with modern mylar capacitors. And then remounted.
> Done that with my receivers.
> Hutch
>
>
> On 1/29/2016 6:47 PM, Sudipta Ghose wrote:
>> This mail is very helpful to me. I have only an oil-filled capacitor
>> that I have not replaced in my BC348N.
>> Now armed with the data about the input current requirement it will be
>> a smooth affair.
>> Regards,
>> Sudipta Ghose VU2UT
>>
>> On Sat, Jan 30, 2016 at 5:56 AM, Robert  Eleazer 
>> <releazer at earthlink.net> wrote:
>>> First thing to do is to check the current drain with the receiver 
>>> powered
>>> up.  I have a BC-348N that had a AC power supply installed exactly 
>>> per the
>>> Surplus Conversion handbook.  Fortunately, the owner did no more 
>>> than that,
>>> even using the ON-Off-MVC- AVC switch as the AC power switch and even
>>> leaving the dial light dimming control intact although disconnected.
>>>
>>> After confirming that the receiver worked I rebuilt the power supply,
>>> removing the dynamotor plate it was using and replacing it with a 
>>> 1/8 in
>>> thick piece of AL.  I added some resistors to the AC line and B+ 
>>> line to get
>>> the B+ down to 200VDC (the Surplus Conversion Handbook has you use a 
>>> 300V
>>> transformer) and added an in-line AC switch to keep from having to 
>>> use the
>>> MVC-AVC switch.  Current drain is about 60 ma and I have left all 
>>> the caps
>>> untouched except for the ones in the power supply.  If your B+ 
>>> current drain
>>> either on an AC supply or the dynamotor is more than 60ma you should 
>>> look
>>> for possible cap leakage.
>>>
>>> Wayne
>>> WB5WSV
>>>
>>> _

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