[jph14]

New to the forum. Just started on a Philco 66S. Wiring in poor shape. Looks like somewhere in the past work was attempted. Bandswitch was gummed up and cracked. Speaker was not wired. The adjusting nut on part 13 was not there- looks like the bolt is broken. This is my first problem- can this be repaired or bypassed or replaced. Original part number is 04000-S.
Thanks,
Joe

[codefox1]

Please post shematic or link. Everything can be repaired, it's just a matter or time and money.

[jph14]

Philco 66.pdf Size: 185.69 KB  Downloads: 231

I completed rewiring the speaker and Hope the bandswitch is good.
Thanks,
Joe

[Radioroslyn]

You should be able to unsolder the broken screw from the back side of the cap and replace it with a new one. You will need a fiber washer and nut to compete the repair
GL
Terry

[jph14]

Thanks. Will give it a try.
Joe

That hopefully worked. Time to clean, check tubes, and replace electrolytics.
Try to handle any problems that now pop up. Anything I should be wary of on this model??
Thanks, Joe

[jph14]

Checked tubes- all good.
Cleaned.
Powered up slowly- steady hum.
Replaced electrolytics- now no hum but nothing else.
Where to next?
Joe

[TA Forbes]

Replace the wax/paper caps and check resistance values. Do you have an AF sig gen to troubleshoot with?

[morzh]

Have you connected an antenna when you were trying to pull stations? It is not likely you will get much except static if you don't have something connected.

[jph14]

All paper caps and resistors replaced.
I do have a Rf signal gen. I did hook up to an outside antenna.
Joe

[Radioroslyn]

Set up your generator to put out a modulated signal at 460KC. Connect it to the grid cap of the 6A7. If the IF and detector are working you should be hear the injected signal.
Terry

[jph14]

Injected signal through grid cap of 6A7 and hear very faint signal.
Should there be some volume control on this signal?
Thanks,
Joe

[Radioroslyn]

Injected signal through grid cap of 6A7 and hear very faint signal.
Should there be some volume control on this signal?
Thanks,
Joe

Yes the volume control should work as usual. Try adjusting the trimmers that are listed to be peaked at 460Kc. All should have a sharp peak. Double check your plate and screen grid voltages on the mixer and IF amp tubes.
Terry

[jph14]

Plate voltages as follows-6A7-231dcv, 78-228dcv, 42-197dcv, 75-58dvc
All seem low especially the 75.

Screen-6A7-81dcv, 78-81dcv, 42-227dcv

All filaments test fine

adjusted all trimmers to max output - still no volume control

Could any of this be a result of incorrectly wired electrolytics? They were not wired and I'm not sure of my accuracy at interpreting the schematic.
Also- on the wire-wound resistor(#44) 22,235 ohms- which terminal does the center tap (9) of power trans. go to?
Thanks,
Joe

[Radioroslyn]

Hmmmm Voltages look ok the CT goes to the terminal that measure 257 ohm from ground. Double check the wiring to the volume control. Seems like you've got something mixed up over there.
Terry

[rghines1]

All voltages are low. The 42 tube may loading down the power supply. Check the G1 voltage on the 42 tube, should be at least -15V.

Center tap of HV winding connects on the 235 ohm resistance side of R44. Otherwise the bias to the 42 tube will be zero overloading the power supply.