[Eric Smith]

Can anyone explain why Philco used bakelite containers for their capacitors? I have never understood the logic of that because it makes replacing those capacitors far more difficult than I think it needs to be.

[morzh]

Eric,

so not to repeat ourselves, we just had that discussion about a week ago right here.
Maybe Ron can find it and direct you to it.

[Steve Davis]

http://www.philcoradio.com/phorum/showth...?tid=14486  

Steve

[Ron Ramirez]

Well...

The previous discussion was about resistors inside bakelite blocks. Eric's question is about bakelite blocks in general.

Hi Eric!

I think Philco did this for several reasons. I can think of a few, perhaps others will chime in with their opinions as well.

1. When Philco started producing the bakelite blocks in 1930, radio was still relatively "new" and manufacturers were still secretive about the components inside their sets. Placing capacitors inside bakelite shells added to the mystery somewhat.

2. Bakelte blocks allowed for convenient tie points for wiring including points to ground in many cases.

3. It was thought at the time that sealing the paper capacitors in high temperature wax would add to their life. Indeed, those capacitors often lasted for several decades. Of course, 80+ years on, they have all gone bad by now and require replacement. (And the wire resistors that were put into some blocks are often still good!)

That's all that I can think of right now...

Yes, they can be a pain in the you know what to replace, but the nice thing is that we can now clean out the old guts, pop in new yellow film capacitors, put the blocks back in place and you can't tell they have been touched save for the new solder on the terminals.

[klondike98]

Also, while its a bit more of a job for us to restuff those blocks today, back in the day when you could simply buy the appropriate replacement block, it would be easy to drop in a new one.

[morzh]

Also popping them out is in fact easy.
We have thread on it here too.

Except the cases where for some reason the eyelets were flooded with solder. Just had one of those in 38-12. The only backelite block there. Funny thing was, no wires protruding through the eyelets when the solder was removed, and inside there were wide foil leads connected to the rivets. That caused some cleaning to be left to do after the broken apart block was extracted. Usually though this is not the case.

http://philcoradio.com/phorum/showthread.php?tid=9107

[Ron Ramirez]

Of all the Philco radios I have worked on over the years...and I've worked on hundreds...I have observed that Philco started filling the eyelets with solder sometime in 1936. These appeared in 1937 model Philcos and continued until they discontinued the bakelite block altogether shortly after World War II.

At the same time...1937 models Philcos were the last to use lots of bakelite blocks. 1938 models began to make more use of the conventional tubular paper capacitors; by the 1939 season, generally only one bakelite block is found: the AC line bypass.

[morzh]

Yep, that was the bypass in 38-12.

And in 37-116 all blocks (quite a few) had eyelets filled. Wasn't too bad, but this does complicate the process just a little.

[Eric Smith]

Also, while its a bit more of a job for us to restuff those blocks today, back in the day when you could simply buy the appropriate replacement block, it would be easy to drop in a new one.

I never thought of that; namely that Philco sold the bakelite units individually with the proper capacitors already in place.  That would serve to make replacing the capacitors that much easier.  Thanks.