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

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

Poss. OSC Problems Philco 34
#2

Marty,

A lot of unnecessary effort there, unless you just want to use it as a teaching tool.

First thing you want to do is to check all the resistors in the LO circuit and replace any that are out of tolerance. This is assuming that you have already replaced all the paper caps in the radio.

Next, remove the oscillator coil and inspect it for broken wires, corrosion, etc. Oscillator coils generally go open due to corrosion on the feedback side of the coil. This is pretty easy to rewind, as a rule. Or you can have someone else rewind it for you.

Also, try subbing in a new tube, as a weak or gassy tube my fail to oscillate while still being able to pass some RF through it.

Another fun thing you can do to test whether the circuit is working as a first detector is to feed in a signal from a generator into the oscillator section (chassis ground and the LO section of the tuner is a good injection point). Choose a strong local station, add 460 KHz to their frequency, and inject that. Tune the tuner to their frequency on the dial, you should hear the station.


Messages In This Thread
Poss. OSC Problems Philco 34 - by marty - 08-16-2013, 12:08 AM
RE: Poss. OSC Problems Philco 34 - by BrendaAnnD - 08-16-2013, 02:10 AM
RE: Poss. OSC Problems Philco 34 - by marty - 08-16-2013, 10:16 AM
RE: Poss. OSC Problems Philco 34 - by Arran - 08-16-2013, 07:42 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-16-2013, 08:37 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-17-2013, 09:43 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-17-2013, 10:23 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-19-2013, 02:48 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-19-2013, 04:13 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-26-2013, 01:38 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-26-2013, 03:12 PM
RE: Poss. OSC Problems Philco 34 - by marty - 08-31-2013, 07:02 PM
RE: Poss. OSC Problems Philco 34 - by marty - 09-02-2013, 10:34 AM
RE: Poss. OSC Problems Philco 34 - by marty - 09-02-2013, 02:28 PM
RE: Poss. OSC Problems Philco 34 - by marty - 09-02-2013, 09:34 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
PT 6 chassis screws size???
Hello bridKarl, that sounds right or maybe 8/32 . Sincerely Richardradiorich — 01:00 AM
PT 6 chassis screws size???
Have this done except for missing chassis screws. It looks like 1 inch 6/32 sheet metal screw may work but can anyone s...bridkarl — 10:32 PM
Philco model 38 code 121 not receiving signal.
Hello Stormlord, Well done on rewinding that coil it turned fairly good for your first one. Sincerely Richardradiorich — 09:12 PM
Philco model 38 code 121 not receiving signal.
Well here it is. It ain't pretty, but hopefully it'll work. I checked it with my DMM on continuity and it keeps and r...Stormlord5500 — 08:56 PM
Philco 42-345 Restoration/Repair
Yes, 57 is an electrolytic cap that should be 12 mfd 400 volts according to the parts list from the Phorum library schem...RodB — 06:01 PM
Philco 42-345 Restoration/Repair
Looks like if I am reading it correctly it looks like the silver capacitor#57 that appears to be a replacement is of a l...osanders0311 — 05:09 PM
Philco model 38 code 121 not receiving signal.
Thanks Arran. Yeah this plastic is pretty thin. It's a little thinner than the original stuff. It kinda reminds me of p...Stormlord5500 — 04:37 PM
Testing a speaker and output transformer Trutone A2-G
The equivalent of one short turn is basically the same as that of a shorted load. If it is the primary's turn, then the ...morzh — 03:53 PM
Testing a speaker and output transformer Trutone A2-G
I've never had an output transformer become shorted, the failure mode is usually an open primary, or in a center tapped ...Arran — 03:52 PM
Philco model 38 code 121 not receiving signal.
As long as the plastic sheeting isn't too thick, I think that the thickness of photographic film would be just about rig...Arran — 03:19 PM

[-]
Who's Online
There are currently 731 online users. [Complete List]
» 1 Member(s) | 730 Guest(s)
Avatar

>