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

38 116 RF tube
#1

I gave a 38 116 to my cousin. I have replaced all caps and out of tolerance resistors.  It played well over a year.

Recently it died so I drove out to see him over the weekend. 

Cheking tubes, the RF rube was dead. I also had no voltage on the plates of the first audio and oscillator (6N7 and 6A8). All components there were correct and not shorted or open where appropriate.   While we wait for a new tube, would a dead RF tube cause the radio to go silent?  I think so but would like an expert opinion to help with troubleshooting if that's not it.

Thanks 
Steve
#2

You might check the resistor numbered 117 on the schematic. This is a chassis mounted wirewound resistor that drops plate voltage to the oscillator and AF tubes. If it opens you will lose plate voltage to the affected tubes.

Also filter cap 70A could be shorted, causing resistor 117 to open.
#3

Thanks. I was thinking that.  I'll check that resistor next trip out there. I need to bring an iron and some tools with me then.

The filter caps are good. All the voltages were close and all they are all new.




Users browsing this thread:
[-]
Recent Posts
Model 70 Cabinet Trim
musar , Well if you have any more questions feel free to post away . Sincerely Richardradiorich — 08:56 PM
Model 70 Cabinet Trim
Although I have not made any cabinets or cabinet parts for a couple of years, I still have some parts left over, includi...Steve Davis — 06:26 PM
philcorepairbench.com - shadow-meter
Thanks Ron.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM

[-]
Who's Online
There are currently 564 online users. [Complete List]
» 2 Member(s) | 562 Guest(s)
AvatarAvatar

>