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

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

38-116 no sound after recap and was playing after recap
#1

Hi all,

I’m hoping someone can give me an idea how to troubleshoot this problem.

I started to align my 38-116 last night. This is one mentioned in a previous post (I was so busy at work I had to stop for a while and I’m just getting back into things). I finished the recap, and it was playing well about 2 years ago when I got busy at work and stopped.  It played well a few days ago as well but It did have an issue with the automatic tuning, however. The mute function didn't work and interfered with reception, cutting it off and on unless I held it in place manually. So after a while of getting nowhere, I changed the tuning dial mechanism with a spare I had. The issue with the mute was gone. I thought that may be the problem, but it wasn’t although the tuning dial mechanism now works as it should.  I could select stations before but now it’s stuck on 570 am and only if I probe the grid cap on the second IF tube with a wire or my finger, otherwise it is silent. I deoxed all the controls, tube bases and grid caps as well.

All the voltages at the tube bases look good and match the schematic within about 10%.

I also don't get any reception at all when I attach a wire/probe to the antenna post or probe the RF, Mixer or detector tubes along the tuning capacitor. These circuits seem to be inoperative even though tubes are nice and warm.

Someone also put a ground from pin 1 on the 6K7 RF tube (6U7 called for in the schematic but the 6K7 is supposed to be a substitute).

I checked the wire would resistors and they are ok.  Otherwise, I'd like suggestions where else to start, I have an old signal injector I need to check for operation in case it can help troubleshoot.

Thanks for your help,
Steve




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
An attempt to remove the Field Coil from a G speaker
Mike; I've only run into a speaker with an open filed coil twice, and they were on newer speakers from the 1940s. One ...Arran — 12:48 AM
An attempt to remove the Field Coil from a G speaker
Arran Yes, this is my plan for now and what do I got to lose, this is not even the speaker from this radio, but one o...morzh — 10:44 PM
An attempt to remove the Field Coil from a G speaker
Mike;  I would unwrap the field coil, and see if maybe there a break near one of the ends, like where the coil wire att...Arran — 10:23 PM
An attempt to remove the Field Coil from a G speaker
...and this is what I did. I fed a little LT into the screwholes with a small brush, and a little on the rim next to the...morzh — 09:52 PM
Philco 40-120C Restoration
I combined the two 40-120C threads together as we like to keep the discussion of the same radio together. It helps with...klondike98 — 09:36 PM
Philco 40-120C Weak, Distorted Ouput
Just checked were I buy tubes price is four dollars. So living in Florid we have a local source for tubes. David    David — 09:14 PM
Philco 40-120C Weak, Distorted Ouput
The higher voltage may be due to higher mains voltage. My mains run 120-125AC when the set was new mains would be 110-11...David — 09:09 PM
Philco 40-120C Weak, Distorted Ouput
Thank you for your reply. I pulled a speaker from a Philco 41-221 and received the same result. I used a signal tracer t...bluecap — 08:45 PM
Philco 40-120C Weak, Distorted Ouput
Have you tried a different speaker? How did you trace the distortion? How do you know it is weak? What is the reference?...morzh — 08:33 PM
Philco 46-480 Electronic Restoration
Amen to that! Every time I think I’ve captured them all, I realize that there’s another error. My goal is to finish with...jrblasde — 07:00 PM

[-]
Who's Online
There are currently 2226 online users. [Complete List]
» 1 Member(s) | 2225 Guest(s)
Avatar

>