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Bakelite block 3903AH info. - Printable Version

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Bakelite block 3903AH info. - Guest - 09-06-2007

I'm doing a recap on a Philco 80, there is a 3903AH bakelite block that I can't find the lug diagram. I have the list of all available here and it's not there, I believe there is one .01mfd inside but at what terminals. Any help would be appreciated.

- Chuck Schwark - 09-06-2007

A twin 0.09uF. (or 0.1uF, 630 v.) block. Mouting hole Lug #1 and Lug #8 tied together, as you see, is the common for both caps to ground thru the mounting screw obviously. One cap goes to Lug #7, the other to Lug #6. See lug diagram on my site in PARTS section for Bakelite Block Consensers.

- Guest - 09-06-2007

I have looked on that chart and it dosen't show a 3903AH. I can do as you said, but am I missing something? does it show it and I don't see it? Thanks for the quick response. Also on my shematic parts list ti shows the 3903AH with a .01mfd. so now i'm really confused.

- Chuck Schwark - 09-07-2007

No, my charts are not all inclusive. Use the info I have above. Use the little bakelite block LUG picture to dertmine the lug numbering scheme.

- Guest - 09-07-2007

Chuck, I fully understand the lug pattern, but why , if you could explain for my future referance. If the schematic says in the parts values and part numbers The 3903AH takes a .01mfd and you say use a 0.09mfd twin. Don't know if I'm just thick, but if you could explain I would sleep better at night.

- Carl Travis - 09-07-2007

The capacitor in question is item 32 on the schematic:
http://www.nostalgiaair.org/PagesByModel/843/M0013843.pdf
It indeed would be .01 and it should be a safety cap since it goes from line to ground.

- Chuck Schwark - 09-07-2007

I didn't say to use 0.09. That's what the block originally came with. I mentioned that the closest vaule nowadays is 0.1uF in parentheses. Use that value and you'll be fine.

- Guest - 09-07-2007

Ok thanks for the help guys. By the way, Just Radios carries the .09uf 630v.