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37-630 I.F. connections?
#1

Hi all,
I'm kind of a newbie to the radio restoration game and ran across a slight issue with my most recent acquisition, a 37-630 radio. The radio had a very loud hum which was eliminated after replacing the capacitors. However I was still getting no reception. Upon inspection of the wiring, I noticed two small black wires coming out of the 1st I.F. transformer which are not listed on the schematic. The coatings on these wires were cracked off and the wires were disconnected. It appeared as if one may have gone to ground and the other to somewhere on the 6K7G I.F. tube. I removed the can on the I.F. transformer and found that the wires went to the center of the middle coil. Anyways, could somebody please tell me where these thin black wires should be soldered to? Any other things I should specifically look for on a 37-630 for no reception?
Thanks
Dad
#2

Cannot find listing for schematic for 37-630 so please post link for schematic for your set. Also state if there is evidence of tampering with the original wiring.

After restoring the power supply with new filter capacitors, replacing all the old wax capacitors, and probably most of the small carbon resistors that have drifted way up, we work backwards from the speaker to the antenna in order to restore the set.
#3

For some reason, the Philco 37-630 schematic is missing at nostalgiaair. It is in JF Riders vol 7 page 7-57 Philco pages. I did a online search and found a nice readable copy of the 37-630 schematic at freeinfosociety. This should help, see link below:

http://www.freeinfosociety.com/electroni...hp?id=1799

If anyone out there has a link to a actual RCA schematic print & parts list for a 1942 RCA model V-215 (anniversary model) I would appreciate a link or scan if possible. I am working on one and it has been previously hacked. My Riders schematic for the V-215 is vague and I found a couple print mistakes in it also. If anyone has the real RCA printed data for this model V-215 chassis please pm me , it would help alot on my restoration here. Icon_thumbup
#4

Only the first four wires indicated on schematic should be coming out of first IF as I read it. Comes up a lot lately, traps for radio beacons of yore near the IF frequency. Look elsewhere first.
#5

This was a revision to the 37-620 and 37-630; documented in Bulletin 251A.

The extra winding is in the 1st IF transformer. The "long black" lead goes to the suppressor grid (pin 5) of the 6K7 IF amplifier tube; the "short black" lead goes to ground.

--
Ron Ramirez
Ferdinand IN
#6

Thanks all for the reponses and help! I'll try hooking the wires up as you described Ron and let you know. I guess if there is still no reception, I'll replace the resistors.
Thanks again for the assists!!!!!
Dad




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