[Milsurplus] PCB'S??

[Al Klase]

Hi Ross,

Here's my thoughts regarding the presences PCB's in bathtub capacitors.

Poly-Chlorinated Biphenols are a class of oils used in indoor
transformers, etc. because they are nonflammable.  I once saw a pole pig
burn after a lightning strike.  You'd want to avoid that inside a
building.  (If memory serves, PCB's were invented by Reginald Fessenden
when he worked as a chemist for Tom Edison.)

However, I believe that small capacitors as used in receivers do not
usually contain PCB as they just don't pose the same danger as 30
gallons of hot oil in a transformer.

I recently removed an Aerovox bathtub form an RCA AR-88 receiver that
had the sticky red seal syndrome.  I drilled a hole on the case and let
it drain in a plastic cup for a while.  I picked up a sample of the oil
on a Q-tip, took it outdoors, and held a match to it.  It burned pretty
much like fuel oil.  I now feel much better about mopping up the oil
inside the radio without taking annoying precautions.

Your mileage may vary.

Regards,
Al

bavarianradio at comcast.net wrote:
> Hello all, I'm beginning a restoration of an RBA-3 WWII receiver. It appears that ALL of the rubber grommets on the oil filled bathtub capacitors have failed. They appear red in color and are sticky and gooey.  I havebeen careful not to touch these (too much anyway) and I wash thouroughlyafter working on this radio.  The question is....  are these caps filledwith PCB's?  and if so what precautions should I be taking?  On a different note, remarkably the radio was working before I took it apart. I was going to clean all the switches and pots and touch up the alignment, withrecapping occurring after a performance evaluation. When I saw the condition of the seals, I thought I had better recap first.  I have a RBM-5 set here also that plays with the original caps and performs nicely! ( I don't leave the room with it on, however)  The caps in the RBM look like new compared to these.  Any thoughts?? 73's Ross
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-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/