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Philco 90 Tone switch caps - Printable Version

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Philco 90 Tone switch caps - Keith Park - 12-27-2007

Anyone have a listing of the values that are in the tone switches?
I have to recap and restuff everything else and leave these, especially when the tone switch seems to do nothing with the old caps.

Thanks

Keith

- Ron Ramirez - 12-27-2007

Hi Keith

Take a look at the schematics I have on my site; these have the parts values added.

http://www.philcoradio.com/tech/schema.htm

All three versions of Model 90 may be found here.

The three capacitors inside the tone control unit are .015, .01 and .01 uF, respectively.

- Keith Park - 12-27-2007

ohhh, thanks! Thats great having the schematics with all the values added... no more going back and forth!

Looks like 2 of the positions had the same tone to them...

THanks Ron!

- Ron Ramirez - 12-27-2007

The individual capacitors add together as they are switched into the tone control circuit. In the first position (Brilliant), none of the capacitors are in the circuit. In the second or "Bright" position, the .015 uF is switched in. In the third or "Mellow" position, both the .015 and the first .01 are paralleled together (.015 + .01 = .025 uF). And in the fourth or "Deep" position, all three caps are in the circuit, paralleled together (.015 + .01 + .01 = .035 uF).

- Keith Park - 12-27-2007

Ahh... I missed that when I looked at it. That makes sense.
This leads me to my next observation., did those speakers EVER give "Brilliant" sound? were the spiders always that stiff even when new?

I often wondered what a 90 would sound like with a good quality speaker attached.....

Thanks again,

Keith

- Ron Ramirez - 12-28-2007

Does your set have a stiff, solid spider like the 1930 Philco speakers? I would have thought all Model 90 sets, whether cathedral or console, would have the open spiders that look sort of like a 45 rpm adapter.

I reconed the speaker in my 370 Lazyboy chairside. Its spider was the open type. Sounds very good with a new cone. Too bad I couldn't find any cones with a paper surround, this one is foam and will require a new surround in about 20 years...but the cone should be good for life, it is made of some type of thin plastic.

If you are adept at reconing and the spider in your speaker is of the solid type, you might consider changing it to an external accordion spider. You'll have to glue it to the speaker frame, behind the cone. You will need to cut out the original solid internal spider, then cover the center hole with felt when the glue dries and the cone, voice coil and external spider are all set. I did that to one speaker and it worked out very well.

- Keith Park - 12-28-2007

Interesting!
Both my 90's had the solid stiff spider... although the speaker in this one I think came from a 70... the one in my 20 deluxe is also the stiff type... I had thought they all were!

Ive reconed some of the larger earlier type speakers from other makes, but since I never found a source for surrounds or cones I really havent done much reconing. Is there a good source for this stuff that I havent found yet??

Thanks

Keith

- Ron Ramirez - 12-28-2007

Yeah, all of the 20 speakers have the stiff internal spider.

Two sources for speaker cones:

http://www.electronix.com/catalog/advanced_search_result.php?keywords=11-75

http://www.matelectronics.com/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2ematelectronics%2ecom%2fcgi%2dbin%2fss000001%2epl%3fRANDOM%3dNETQUOTEVAR%253ARANDOM%26PAGE%3dSEARCH%26SS%3dspeaker%20cone%26TB%3dA%26GB%3dA%26SX%3d0%26ACTION%3dSearch&WD=speaker%20cone&PN=Mat_Electronics_Speaker___Accessories_11%2ehtml%23aPCE_2d12#aPCE_2d12

MAT Electronics also carries external accordion spiders.

There are other sources for these as well, I am sure.

I have yet to find a source for cones suitable for use in the 10-1/2 inch diameter Philco speakers. 10 inch cones are too small, 12 inch cones are too big.

I've only done a little bit of reconing for myself, and only 8 inch speakers so far. I consider my reconing work to still be in the sloppy stage, compared to a pro such as Hank Brazeal, But so far, all but one have turned out really well as far as sound quality is concerned. I'll eventually redo the one that did not turn out so well...

- Keith Park - 12-29-2007

Ahh.. I had never found any! and for pennies! WOW! you never see THAT anymore! I should buy some just to have them in stock. Ive run into many of the later Philco speakers that have damaged cones.

I fixed the open side of the output transformer on this set and its working pretty well now, bit of a slow warmup but Im using all globe tubes in it (except for the rectifier).

Should have the cabinet done tommoro.....

Thanks,

- Texasrocker - 01-11-2008

not trying to hijack this thread. I remember a few yrs back when I restored a nice orig Philco 90 (missing orig spkr & trans), .. I subbed a modern type "musak" type full range 8" paper cone spkr, ( if memory serves me) , I had to make a new baffle-board to accomadate with orig fnt cabinet brass spkr screws?... and add the appropriate 10 watt wirewound resister for missing field-coil, ... but the new PM type spkr sounded AWESOME!! At least I saved a old Philco mod 90 for one of my customers. They found the radio in a barn outside Amarillo,Tx, and it had been hacked badly under chassis as well. Philco 90s sound GREAT with modern type PM spkrs added if you ever have to make that choice in the future!! Sincerely, TxRockr