Philco 37-610 tombstone restoration - Printable Version
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RE: Philco 37-610 tombstone restoration - morzh - 04-05-2018
Repair is not easy. Finding is not easy either. Repair is simpler because you pay to the people who will rewind it for you, like Heyboer.
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-06-2018
Well, today I got some time to check and for the moment the transformer is healthy in ohm values only the primary that should be 5ohm is 6,5-7 ohms also all wires of it go to the correct place as in schematics, the 80 tube I do not know if is possible to check a short somehow with a ohmmeter, between pins #7&8 is little ohms, is this telling something? I am going to remove the #56 Ecap to check it, is easy access and I do not need to remove the can
RE: Philco 37-610 tombstone restoration - Radioroslyn - 04-06-2018
7 and 8 would have some resistance but it's going to several ohms. What you are seeing is the resistance from heater winding ground thru the bias resistor and half of the HV winding.
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Hi Terry, thanks, I explained it bad, the little (3ohms) resistance I found was in the tube not connected, heater pins, this means that the filament is ok or is shorted? By the way I did the full check and @ 100vac (I was little afraid to go full voltage) all tubes changed with old spares I got time ago except the 80 (not installed as was told) and the 6v6 that had no other one, speaker installed again, Ecap #56 changed(was not bad but the tester showed some leaking) raising voltage slow everything was ok, at 100vac only 0,01amp was drained, all filaments in tubes were shining normally and the voltages in the socket of the 80 are 4,6volt for filament pins and 570 for the HV, this means that the rectifier was bad?
Thanks
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Some pictures
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Filaments glowing
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Old tubes for test
RE: Philco 37-610 tombstone restoration - Radioroslyn - 04-07-2018
Ok next step would be measure the resistance from pin 1 to chassis and then pin 4 to the chassis at the 80 socket. Both should show high resistance like 7000 ohms or higher.
If that is ok then measure the resistance across pins 1 and 4 (the two fat ones) on the 80 tube's base (again not installed). Should see a very low resistance just a few ohms. If it's open (no resistance) the tube will need to be replaced as the filament is broken. With a dead tube you can carefully bust the glass off of it and unsolder the wires from the pins. This can be used for a spkr plug or a tube adapter at a later date.
GL
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Ok, checked as you said radioslyn, hope pin one is the same that are you talking about...from pin 1 to chassis I have only 258ohm and pin 4 460ohm... Any hint for a trouble?
Thanks
RE: Philco 37-610 tombstone restoration - Radioroslyn - 04-07-2018
So where is the 80 tube???
Looks like you have a 5Y4. Electrically they are the same but the pin out is different.
80 tube 5Y4 tube
pin 1 = pin 8
pin 2 = pin 3
pin 3 = pin 5
pin 4 = pin 7
Recheck resistances using these pin #'s
pin 1 of the 5Y4 has no internal connection so it must be used as a tie point or you are miscounting them. from the bottom view count clockwise top view count counter clockwise.
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-07-2018
Yes is a 5y4gt, I thought was same, that is the reason I was calling it 80
from pin 8 is the photo I posted before
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-08-2018
From both pin #7&8 of the socket to chasis 258ohm
RE: Philco 37-610 tombstone restoration - Radioroslyn - 04-08-2018
Not liking that too much!
You got a few possibilities. Transformer is misswired. The 5v filament winding and one of the hv wires got connected together. #56 is shorted. Or the transformer is shorted. Seems the yellow/green wire is connected to the blue one. Am thinking that you are seeing the resistance from #54 over on the hv side
I would pull the top cover off of the transformer and check the resistances of the windings vs the ones noted on the diagram. Use this to determine which winding are which. Then check that they are connected to the appropriate connection.
Happy hunting!
RE: Philco 37-610 tombstone restoration - Jeepeto - 04-09-2018
Thanks a lot for the hint! At the end checkingthe schematics and unsoldering the wires that goes to the #56 Ecap gave me the answer for the moment: one wire wrong, I remember to tag that wire "go to #56" but from bias resistor to negative side, and was in positive... Changed it, and now the resistance (after checking that the transformer was not shorted) is arround 70kohm, with all tubes (less rectifier) I tried now with 90vac and looks ok, should I try now to plug the rectifier and check voltages in ecaps?
Thanks again for the help
RE: Philco 37-610 tombstone restoration - Radioroslyn - 04-09-2018
Your probably ok to give it a try just keep an eye on the hv across #56. Would think that it should be at about 300vdc. If much lower (like 200v) I would replace 56.
GL