Philco 60 restoration

[leadlike]

Anyone ever try filling those wet lytics with borax solution again?

[bandersen]

Not that I know of. Sounds like an interesting experiment.

[Reece]

I think people have done that and then reformed the plates and all but...nice experiment, but I don't think I'd leave one in a radio.

[compucat]

Originally Posted by leadlike

Anyone ever try filling those wet lytics with borax solution again?

When I restored my 1937 Philco 610 the original electrolytics still had liquid in them. I drained it out, sealed the ends and installed replacement caps under the chassis. It amazes me how some of this stuff worked when new.

[bandersen]

I've finished rebuilding the tone control. There are two capacitors mounted inside a little box. They're connected together at one end that goes to the output tube. The other end of one is grounded. The other cap can be switch in parallel or left disconnected. I potted it with black hot glue and polished it all up with Simichrome.

Kinda complicated for a two position tone control if you ask me!

[PaulOF]

Wow! That is just beauteousful.
Paul

[bandersen]

Thanks! I also spent a looooong time masking off the chassis and gave it a couple coats of Rustoleum Specialty metallic Chrome.
I followed that up with a couple coats of clear semi-gloss enamel. It's a pretty good match to cadmium plating I think.

I'll let it cure for a couple days then i can finally start putting this all back together!

[leadlike]

Well, at least your tone control will work-mine is shorted out to the chassis, so it only works on the one setting. I'm guessing there should a be a fiber spacer or something on the control shaft that failed on mine. The set certainly lacks that 1930s "booming bass" that I'm used to.

[bandersen]

Originally Posted by leadlike

Well, at least your tone control will work-mine is shorted out to the chassis, so it only works on the one setting. I'm guessing there should a be a fiber spacer or something on the control shaft that failed on mine. The set certainly lacks that 1930s "booming bass" that I'm used to.

The shaft should be ground it's the little contact pad that needs to be insulated. I think if that's shorted to the chassis (ground), you'll have a larger capacitance on the output which will filter out the lower frequencies.

I suppose you could just snip the wire to that switch contact.

[bandersen]

The painted chassis has cured up real nice so it's finally time to put it all back together.
Good thing I took loads of reference photos

[bandersen]

I removed the speaker from the cabinet for closer inspection.
It looks fine from the back - not so much from the front.
I measure 432 on the output transformer which is close to the 400 on the schematic. The voice coil is dead on at 1.14 K.
Unfortunately, the VC seems to be open I'm not sure if it would be more practical to hunt for a new speaker or get this one repaired

[bandersen]

It took me longer than it should have to realize that this speaker has been reconed - or at least someone attempted to recone it.

The new cone is off center, the surround is just scraps of cone material, and the spider and VC are missing


I figure it should look just like this speaker from a Philco 38-10.


I'm all for trying to recone it myself, but have never done it before.

I found Weber Speakers sells all sorts of reconing parts but am not sure what to order. Does anyone even sell spiders that screw on like these old Philcos ?

Or maybe I'm in over my head and should just send it out for repairs. Any suggestions ?

[leadlike]

You're lucky in that this speaker was used in many Philco cathedral models. A few months ago, I fixed three Philco cathedrals for someone else, and they all used that speaker. And for all the changes the model 60 went through, the speaker seems to have stayed the same.

[GuyIncognito]

This article about the restoration of an Atwater Kent 206 describes (among other things!) a method for making a new voice coil/cone (look about half way down):

http://ludens.cl/Radiohis/ak206/ak206.html

(It seems implied to me that he fashioned a new spider out of card stock)

While his restoration wouldn't bear up to scrutiny of a concourse-type inspection, you certainly can't fault this guy's ingenuity. The lengths that he goes to to revive this old set are nothing short of inspirational!

Since you have all the other bits and pieces of the speaker, perhaps a similar method could be improvised...? He had access to a lathe, but maybe a somewhat less precise "former" could be attempted with a vertical fixed dowel rod and a concentric circle marked on the work table as a guide for the outer edge of the cone?

[GuyIncognito]

The quickest "fix" (term used generously) is to find a smaller PM speaker that will fit in the steel "basket" and secure it there. You can retain the field coil and output transformer and won't have to make any modifications to the radio's circuitry, plus the radio will appear more or less original from the back.

Of course, the sound won't be quite as nice--but acceptable. A working radio runs circles around a silent one!