The PHILCO Phorum
Philco 37-650 - Printable Version

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Philco 37-650 - Oldresistor47 - 08-06-2016

I'm new to this site. I need help on locating the on/off, tone control pot for this Philco model. The tone portion is not working properly and the on/off metal piece is fatigued. After changing electrolytics, it still draws too much current.  It'll play fine at 110 volts.  House current is usually 123.  Any suggestions or should I install a limiting resistor? Thanks

RE: Philco 37-650 - Radioroslyn - 08-07-2016

Hi and Welcome,
Been a while since I seen a tone switch on a '37 model. The older ones are some what serviceable so you maybe able to add a little solder to reinforce the contacts. Or place an ad on the Phorum in the Wanted section, or rewire it to use a 250k-1meg pot w/a switch to turn it off and on and serve as a variable tone control.

If you only replaced the electrolytics in the p/s section your asking for low performance and problems. I understand that the '37 models are a bit more work because of the dual chassis but that could very well be your consumption problem.
GL

RE: Philco 37-650 - klondike98 - 08-07-2016

Welcome to the Phorum!
Icon_wave

RE: Philco 37-650 - Oldresistor47 - 08-07-2016

(08-06-2016, 10:22 PM)Oldresistor47 Wrote:  I'm new to this site. I need help on locating the on/off, tone control pot for this Philco model. The tone portion is not working properly and the on/off metal piece is fatigued. After changing electrolytics, it still draws too much current.  It'll play fine at 110 volts.  House current is usually 123.  Any suggestions or should I install a limiting resistor? Thanks

Thank you.  Did try a new pot but it wasn't right. Reinstalled old one, crossing my fingers the metal catch for the off side of switch holds, while I locate one. I understand lixdeslia.

RE: Philco 37-650 - Oldresistor47 - 08-07-2016

Thank You.

RE: Philco 37-650 - morzh - 08-07-2016

Electrolytics are about 20% of work if you rebuild them and 5% if you replace them.
As Terry said, you need full recap. Plus some. But the recap (provided your tubes are good and transformer is not leaky) should take cars of excessive current draw.

RE: Philco 37-650 - Oldresistor47 - 08-07-2016

Didn't mean to infer just the electrolytics were replaced. All but the mica's were changed out and resistors. Had to replace two tubes but the others checked ok. I'll recheck the transformer, initial checks indicated resistances were within tolerances. I'll replace the 5y4 (rectifier) with another good one and see if that helps. Sounds good at 110v. Nothing is overheating.
Thanks for the help.

RE: Philco 37-650 - morzh - 08-07-2016

Well

You did not say what exactly "too much current" stands for vs expected.

If you think it is too much so you have to worry about it, first see if the #59 cap is correctly polarised (plus on chassis).
Then see if your power xfmr draws any really significant current when plugged with the rectifier tube and the rest of tne tubes removed. Then start with output tubes and rectifier together, then keep adding others. See if any of them jumps the consumption.

RE: Philco 37-650 - Oldresistor47 - 08-08-2016

Great advice. Will try it.

RE: Philco 37-650 - Radioroslyn - 08-08-2016

(08-07-2016, 06:02 PM)Oldresistor47 Wrote:  
(08-06-2016, 10:22 PM)Oldresistor47 Wrote:  I'm new to this site. I need help on locating the on/off, tone control pot for this Philco model. The tone portion is not working properly and the on/off metal piece is fatigued. After changing electrolytics, it still draws too much current.  It'll play fine at 110 volts.  House current is usually 123.  Any suggestions or should I install a limiting resistor? Thanks

Thank you.  Did try a new pot but it wasn't right. Reinstalled old one, crossing my fingers the metal catch for the off side of switch holds, while I locate one. I understand lixdeslia.

If the off/on switch is just stiff a little slug of Deoxit may be the fix for it. Just make sure that the Deoxit has dried completely. No fun having the switch go up in flames.

Your very welcome!

RE: Philco 37-650 - Oldresistor47 - 08-08-2017

Thought I had the combo on/off, tone switch repaired but it threw the ball bearing used to lock it into the four positions. Can anyone send me a picture of an original control? Or can you tell me what holds the bearing in place?

RE: Philco 37-650 - Oldresistor47 - 08-17-2017

i can't get any stations on the lower numbers 560-710.  Any advice on where to look for the issue.  I can't seem to get any movement on the antenna adjustments on the sub chassis either.

RE: Philco 37-650 - Radioroslyn - 08-17-2017

>i can't get any stations on the lower numbers 560-710.
If you connect your antenna to the grid cap of the 6A8 can you receive stations at the lower end of the bcb??
A weak 6A8 could cause this situation. Also using a tube extender to access the tube pins from the top to measure the dc voltages at the 6A8.
> I can't seem to get any movement on the antenna adjustments
Don't understand your question. No adjustments on the sub chassis will move your antenna. Pls restate.

RE: Philco 37-650 - Oldresistor47 - 08-18-2017

I have a 6A8 on order. Tube tester shows it as good but suppressor grid voltage falls to 50v with it in the circuit, when it should be 100v.. The compensators 10&4 do not show any movement on the meter when trying to align the Broadcast band. Thanks for the advise.

RE: Philco 37-650 - Radioroslyn - 08-18-2017

< The compensators 10&4 do not show any movement on the meter when trying to align the Broadcast band. 

You can check the rf coils by:
#1 measuring the resistance from chassis ground to red and then the black ant terminals. Both should show a low resistance. Jumper must be in place as shown on diagram.
#2 Measure the resistance from the junction of #'s 6 and 7 to the ant section stator of the tuning cap.
These steps checks the ant coil.  
#3 Measure the resistance from pin 3 of the 6K7 to the ungrounded side of #15.
#4 Measure the resistance from #7 marked B2 on the diagram to the stator of the rf amp section of the tuning cap.
These steps check the rf coil.
Rotate the band switch to measure the coil on other bands. All coil should be under 25ohms or so.

Could have a bad ant or rf amp coil. I remember Ron mentioning something about the 37-650 having a problematic band switch due to arcing and burning contacts.

> Thanks for the advise.
Your welcome!