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Philco 37-660
03-02-2012, 09:56 PM
Post: #1
Philco 37-660
I just brought home a 37-660 and although I've worked many radios I would like some input from anyone who has tackled one of these. It is obvious sections of the radio will need to be removed in order to access caps/resistors that need to be changed.

Any suggestions as to where to begin? Seems like one will almost have to replace most of the caps/resistors before firing the thing up (not one or two and then check operation). Also any hints/problems on removing the dial etc?

I have the schematic from NA and my quick review of things find different values for some caps. Are there different versions?

BTW, this particular radio has never been serviced except for tube replacement. All of the compnents are original. Must not have been played for a long time.
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03-02-2012, 10:10 PM
Post: #2
RE: Philco 37-660
Hi Marv and welcome to The Phorum!

Changing all caps is a must and also checking and replacing any resistors that are outside the +/-20% of nominal values, as listed in the parts list for the set. A great performer when back running again.

Make sure you have a good schematic and alignment info, including Production Change Notes, many which Rider's failed to re-publish. Your set also could be a different Code version chassis. Components many times were changed in different Run numbers as well.

Chuck

Chuck Schwark,
The Philco Repair Bench
[Image: philog3tiny.gif]
http://www.philcorepairbench.com
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03-02-2012, 10:41 PM
Post: #3
RE: Philco 37-660
Hi Marv
Just want to stop by and say welcome to the Phourm.
As to where to start well where ever you want. There's
lots to fix but I would start with the caps. You got one of those set with a sub chassis (most of the 1937 models) which is kinda pita to service.
Terry








(03-02-2012 09:56 PM)marv Wrote:  I just brought home a 37-660 and although I've worked many radios I would like some input from anyone who has tackled one of these. It is obvious sections of the radio will need to be removed in order to access caps/resistors that need to be changed.

Any suggestions as to where to begin? Seems like one will almost have to replace most of the caps/resistors before firing the thing up (not one or two and then check operation). Also any hints/problems on removing the dial etc?

I have the schematic from NA and my quick review of things find different values for some caps. Are there different versions?

BTW, this particular radio has never been serviced except for tube replacement. All of the compnents are original. Must not have been played for a long time.
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03-02-2012, 11:15 PM
Post: #4
RE: Philco 37-660
Hello, Marv: I just happen to be working on a 37-660 right now, which is very similar to your 665.

Caps #60 and #68 are .003mFd, 1000V rated caps. Rather than take a chance with my poly 630V caps, I ordered some .0033/1600V replacements. I don't think you need to go any higher than 1000V, but the 1600Vs were available to me so I went with them.

The rest of your paper caps should be fine replaced by the 600/630V varieties offered by many vendors. Your electrolytics should be fine replaced by 450V varieties. NOTE that in addition to the two 8mFd electrolytics located near the power transformer, you also have a small electrolytic can on the RF deck that houses 1, 2, and 3mFd caps. I strongly recommend you replace these, as all 3 are in contact with B+.

In order to replace the can and the paper caps in/on the RF deck you will have to remove the deck to get at them. This is not a simple task. Make sure you diagram and mark the wires as you de-solder them.
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03-03-2012, 01:17 AM
Post: #5
RE: Philco 37-660
Thanks to all. Technically I'm a new member because it has been a long time since I logged on and had to re-registor. I used to know where to find the info on the bakelite caps but have forgotten. Can anyone direct me to it? Thanks again. Also thanks for the heads up on the high volatage caps.
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03-03-2012, 02:09 AM
Post: #6
RE: Philco 37-660
http://www.philcoradio.com/tech/blocks.htm

http://www.philcorepairbench.com/bblokcap.htm

Info on how to rebuild these:
http://www.philcorepairbench.com/capbuild.htm

--
Ron Ramirez
Ferdinand, IN
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03-03-2012, 05:28 AM
Post: #7
RE: Philco 37-660
(03-02-2012 11:15 PM)TA Forbes Wrote:  Hello, Marv: I just happen to be working on a 37-660 right now, which is very similar to your 665.

NOTE that in addition to the two 8mFd electrolytics located near the power transformer, you also have a small electrolytic can on the RF deck that houses 1, 2, and 3mFd caps. I strongly recommend you replace these, as all 3 are in contact with B+.

In order to replace the can and the paper caps in/on the RF deck you will have to remove the deck to get at them. This is not a simple task. Make sure you diagram and mark the wires as you de-solder them.

Since the small electrolytic can is located in the hard to access RF deck it may be an idea to substitute poly film caps for the small electrolytics so they don't have to be dealt with again, if you have the room or can stuff them inside the can.
Regards
Arran
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03-03-2012, 09:17 PM
Post: #8
RE: Philco 37-660
Thanks for the information. Am currently identifying/locating all of the parts so I can get my order out.
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03-03-2012, 10:40 PM
Post: #9
RE: Philco 37-660
I see there is a service bulletin 257 for the 37-660. To increrase base response they changed C77 from .008 to .006 and changed resistor R36 from 51k to ??? I cannot find the value for the new part number 33-340339. Can anyone help?

marv
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03-04-2012, 07:56 AM
Post: #10
RE: Philco 37-660
Not a major concern.
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03-04-2012, 01:31 PM
Post: #11
RE: Philco 37-660
(03-03-2012 10:40 PM)marv Wrote:  I cannot find the value for the new part number 33-340339.

It's right there in the part number:

340 = 40,000 ohms. The multiplier, in this case being 3 for three zeroes, followed by the first two digits of the value, 40. 339 means 1/2 watt.

Read about it here:
http://www.philcoradio.com/tech/resistor.htm

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Ron Ramirez
Ferdinand, IN
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03-14-2012, 09:29 PM
Post: #12
RE: Philco 37-660
I'm in the middle of replacing parts and have come across two resistors around the 2nd detector/AVC circuit that don't agree with the schematic. Resitors 44 and 46 (according to the schematic) should be 99k and 490k respectively. What is there are two 240k. Do I stay with those values?

http://www.nostalgiaair.org/PagesByModel...013220.pdf
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03-15-2012, 01:24 AM
Post: #13
RE: Philco 37-660
Thanks for providing a quick link to the schematic.

Go with what is in the radio. Generally the best policy. In this case it appears with both resistors at 240K, it gives better filtering/removal of the RF component with a slight reduction of the audio component reaching the volume control.

Richard
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03-15-2012, 01:50 AM
Post: #14
RE: Philco 37-660
Thank you Richard. Was going to mention that when stuffing one of the 8ufd lytics, when I cut into the can to my suprise it was FULL of electrolite. I never saw this before in a 75 yr radio. This can't be too common can it?
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03-15-2012, 06:31 AM
Post: #15
RE: Philco 37-660
(03-15-2012 01:50 AM)marv Wrote:  Thank you Richard. Was going to mention that when stuffing one of the 8ufd lytics, when I cut into the can to my suprise it was FULL of electrolite. I never saw this before in a 75 yr radio. This can't be too common can it?

Yeah, hook up one of these up backwards and sure am glad I had glasses on. Don't take chances like that anymore.
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