[HAM] Recapping

[David Anderson]

Kon,

I have a 1963 A-100 with the kind of paper capacitors Scott is  
referring to. They don't have wax on the outside, but I've never cut  
one open to find out exactly how they are different inside from  
earlier paper capacitors. It's possible that the cardboard was  
impregnated with some kind of resin for waterproofing.

The real weak spot of the wax-dipped capacitors, however, was the  
unavoidable point where the lead goes through the wax. When wax gets  
warm, it gets soft enough for any movement to open a route for air to  
enter, and it can crack when it gets too cold. I would imagine  
something like a cross-country trip in a truck during the summer  
would not be good for these.

Manufacturers were painfully aware of the shortcomings of this  
technology. In one book from the period on capacitor design, the  
author tells the story of an engineer who designed an early  
television that worked fine in the lab. When used in humid places,  
however, they failed in large numbers. There are stories of repairmen  
who resorted to putting light bulbs inside early TVs  just to try to  
keep them working. The light bulb would keep them warm enough inside  
to decrease the ambient humidity.

But the other point I was trying to make was that you simply can't  
forget history and make generalizations about particular kinds of  
capacitors. Let's use an analogy. You could, for example, have two  
1964 Ford Mustangs: one spends most of its life in the dry climate of  
Arizona, garaged when not driven; the other spends its life outside  
near the ocean, exposed to salt spray. Let's say the first one is  
painted red, and the second one, blue. If someone showed you the two  
cars and didn't tell you their history, would you draw the conclusion  
that red Mustangs seem much more immune to rust than blue Mustangs?  
Would that be sound reasoning?

David

On Mar 3, 2008, at 12:09 AM, Kon Zissis wrote:

> I believe that Scott Hawthorn was referring to the same  particular
> types  wax paper capacitors that I was referring to when he used the
> term ''cardboard covered''.
>
> Thus far I have only seen these types of capacitors on a 1937 BC  
> organ ,
> but Scott has seen them on 1964 organs so therefore I suspect that
> Hammond used them  indiscriminately depending on what batches were
> available at the time of their bulk purchase ordering from the various
> vendors.