The PHILCO Phorum
New Member - Newbie question - Printable Version

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RE: New Member - Newbie question - Eric T - 01-26-2013

This sounds like what I've been going through on a 42-1008. The highest value resistor from the HV secondary center tap to ground smokes and opens.

Check the voltages on your rectifier plates to to ground. Please, be VERY careful-- this thing can bite you hard. They should both be roughly the same (~350VAC). If one is really high and the other one is around zero, you have a transformer winding shorted to ground on the HV secondary. That will smoke that resistor in a jiffy. If this is the case, one of the yellow wires coming out of the transformer probably has some bad insulation and is touching the transformer shell somewhere.

RE: New Member - Newbie question - codefox1 - 01-27-2013

Say again:

Replace each and every electrolytic and wax capacitor before carefully powering up slowly with a variac or dim bulb tester.

RE: New Member - Newbie question - Mr Grumpy - 01-29-2013

Quote:Posted by codefox1 - 01-26-2013 11:26 PM
Say again:

Replace each and every electrolytic and wax capacitor before carefully powering up slowly with a variac or dim bulb tester.

Okay, Im going to build a dim bulb tester and start recapping.
Im slightly concerned that ill get heavily invested into this and then not be able to fix the issues to get it working again, but so far the help ive received here is making me feel a bit better about this.

Thanks for all the help so far. will report back once we get to phase 2.

RE: New Member - Newbie question - Mr Grumpy - 02-02-2013

Okay next problem everyone, (newb question)

I'm going through the capacitor list and getting ready to place an order online when I came across a capacitor that I was unsure of. It's listed on the schematic as #81 dual .01-.01 mfd. Below is an image of the schematic and an image of the outline of # 81. It looks like a black plastic terminal strip and is actually visible in the image that Ron posted previously. My question is, is this thing a capacitor or are there capacitors inside of it? How do I replace these two .01mfd capacitors??

[Image: http://i835.photobucket.com/albums/zz278/cacarella/81cropped_zps2609b0dd.jpg]

[Image: http://i835.photobucket.com/albums/zz278/cacarella/81imagecrop_zps6e568411.jpg]

RE: New Member - Newbie question - kporter - 02-02-2013

Yes, there are two .01 uF capacitors inside the bakelite housing. Quite common in many Philco radios of that vintage. You're about to embark on another great adventure in radio restoration. It's actually not hard to do.

And since those two caps are across the power line, you should replace them with "safety capacitors" while your are at it.

Chuck's excellent site tells how to do it: http://www.philcorepairbench.com/capbuild.htm

Safety capacitors are discussed here : http://www.justradios.com/safetytips.html

RE: New Member - Newbie question - Mr Grumpy - 02-03-2013

Brilliant. Thank you so much for the help and pointing me in the right direction.
I'm hoping to get all the caps I need and get this done in the next few weeks.
Hopefully the next time you hear from me I'll have a fully functioning radio and record player
that I can post pictures of.

RE: New Member - Newbie question - Mr Grumpy - 02-10-2013

Hi all, Me again.

I've been replacing all the caps and came across a problem with the electrolytic capacitors that I'm hoping someone will help me out with. It's obvious that there has been a repair and replacement made in the past as two of the wires leading from the capacitor can have been cut and a large cardboard capacitor added to the underside of the chassis. I'm not sure where to begin to describe the issue I have but maybe just a simple answer about what I should be seeing based on the schematic will clear things up for me.

[Image: http://i835.photobucket.com/albums/zz278/cacarella/21a-bElec_zps6c2b1ac2.jpg]

Cap 21B appears to be the one that was replaced. This large cardboard cap has a wire coming out of it that leads to a terminal which is mated to the speaker field coil (76) while the other wire exiting the cap leads to the terminal between the two large resistors on my new Candohm resistor. Cap 21a Looks to still be inside the original can, it has a red wire that comes out of the can and goes to the field coil (and a bunch of resistors) but there is no wire that comes out of the can that leads to my candohm resistor between the 28 and 26 ohm section. Since there was only two wires cut from the original capacitor can which I'm thinking was for 21B, was there never a wire that went to the candohm? The green wire and Black wire seem to be going to the proper places, I'm just not sure what I'm supposed to be seeing here.

Also, based on the schematic above of the Electrolytic capacitor does the little black box represent the positive side?
I guess I was also confused because I always thought the negative side just went to a ground on the chassis.

Any help would be greatly appreciated.

EDIT-- Wait a minute, I think I just figured something out here when reviewing my post, is the Candohm resistor considered a ground because the last 26ohm resistor is connected to a ground? - I told you I was new to this right!?!

RE: New Member - Newbie question - klondike98 - 02-10-2013

Yes the small black box represents the positive side of the electrolytic caps. There was an earlier thread on this topic that might help, see: http://philcoradio.com/phorum/showthread.php?tid=981&pid=4580#pid4580 and http://philcoradio.com/phorum/showthread.php?tid=989&highlight=41-608 .

RE: New Member - Newbie question - Mr Grumpy - 02-10-2013

Thank you again!