Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Restoring a Philco 71 Code 121-No sound
#17

Try using another meter, a VOM is recommended. The readings, now, are not really out of line. Re-solder the terminals of the observed offending coil.

Check the capacitors in the circuit. Schematic seems to indicate four variable condensers. At least two are the main tuning condenser and its (mounted) compression trimmer. Any leakage from damage, corrosion or dust can kill the oscillator.

NOT associated with any particular radio is that the insulators for the stator of tuning variable condensers have been known to leak. Poor electro-mechanical connections to the rotor can also be troublesome.

I see no copper corrosion but, the decaying celluloid can be a source of low resistance by shorting turns of the tickler, unseen on the inside of the winding.

The tickler is at cathode potential, any leakage to the other windings which reference ground, will carry some of the total plate current.

GL

Chas

Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”


Messages In This Thread
RE: Restoring a Philco 71 Code 121-No sound - by Chas - 07-07-2024, 12:22 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Model 80 Antenna Issue?
Hello Hamilton, here is a little information found in our Philco Radio Library at the bottom of the Home page. Hope it ...GarySP — 11:28 AM
Model 80 Antenna Issue?
I did as you suggested and touching the middle of the volume control did nothing so the coil has to be rewound. Any idea...Hamilton — 10:19 AM
1949 Motorola 5A9M
This would be the second portable in the "other radios" forum where I have a similar one in my collection. I h...Arran — 12:41 AM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hi PittsburgTost. The record changer looks like a Garrard or BSR (Likely Garrard). The spindles just pull out and pu...MrFixr55 — 11:57 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hello PittsburghToast , Welcome aboard and it looks like gary may have something for you ! now if I dig through my se...radiorich — 11:35 PM
Model 80 Antenna Issue?
You are kind of on the right path. You can touch the grid cap of the Detector/Oscillator 36 tube. I'm expecting a respon...RodB — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum, PittsburghToast!  I found an old thread that my interest you regarding the quality and worth of P...GarySP — 08:48 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Welcome to the Phorum! :wave: We do not have anything on that unit in our digital library. There is a Sam's Photof...klondike98 — 08:47 PM
Model 80 Antenna Issue?
I’ve replaced all the caps and resistors and the radio is working but minimal volume unless I put my hand near the re...Hamilton — 08:24 PM
Looking for any info: 1977 Ford-Philco Console Hi-Fi Turntable and Radio
Hi there! this is my first time posting. I recently picked up this Ford-Philco Console record player and radio at a yard...PittsburghToast — 07:28 PM

[-]
Who's Online
There are currently 328 online users. [Complete List]
» 3 Member(s) | 325 Guest(s)
AvatarAvatarAvatar

>