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

116X plummeting B voltage
#1

Hello,
Foolishly, I was attempting to align this radio with a screwdriver and shorted something in the process. I was very close to finishing and now, there is no sound, the wirewound resistor(part96), transformer (part 92), and one of the 6A3s all get very warm almost hot to touch. When I power up the radio, I observe the B voltage at the input filter(part103) climb to about 280vdc then there is a pop in the speaker and the voltage drops in a hurry to about 150vdc and things start to get warm.The power transformer seems to be ok. Live and learn, as I should have known better. Where should I look to troubleshoot this problem, please point me in the right direction. Thanks, in advance.
Marc
#2

Check for negative voltage on the grids of the 6A3's. Should be about -60v. If you don't have it on both grids Check the center tap of the driver transformer (92) If you got it there replace 92. Check for plate voltage on the # 42 tube. If is is low replace (92) Also try removing the #42 and watch the b+ to see if it drops as the set warms up.
Terry
#3

Thanks. I really appreciate this information. Through no effort on my part, the B voltage has resumed normal values...so the problem may actually an intermittent one. I will follow through. Marc.
#4

Glad to hear it seems to be OK. You may want to put a small fuse in the CT of the HV winding of the power transformer. Just to be safe. Should be a great sounding set! I've got the 37-116.
Terry

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#5

I edited the topic title to avoid confusion. There is no such thing as a 36-116X. The correct model number is 116X.

Intermittent problems can be the toughest ones to solve. Terry's given you some excellent advice, Marc; best of luck with your set.

--
Ron Ramirez
Ferdinand IN




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Battery-WWII vintage
My younger sister went to SUNY Plattsburg NY, (BS, MS, RN) in the late 1970sabout 10 min from the Northern NY / Canada b...MrFixr55 — 07:59 AM
Philco Battery-WWII vintage
Hello Bob, What Amazing find! Sincerely Richardradiorich — 10:19 PM
Testing a speaker and output transformer Trutone A2-G
Hi Murf, Do this: Monitor between ground and one plate of the rectifier while playing the radio.  Do the same with ...MrFixr55 — 09:51 PM
Philco Battery-WWII vintage
Mike; I take it that Soviet cars did not come equipped with block heaters, hence the hot oil change? Where I lived in...Arran — 08:42 PM
Philco 42-345 Restoration/Repair
The more the better. (Within reasonable limits.) 2-5 times more is no problem in this case.Vlad95 — 03:50 PM
Philco 42-345 Restoration/Repair
Thanks, RodB and Vlad95, I was mainly trying to figure out this capacitor to locate a replacement, Vlad thank you for...osanders0311 — 03:44 PM
Testing a speaker and output transformer Trutone A2-G
Would an output transformer if weak, cause the problems I am seeing with lower B+ voltage? murfmurf — 01:22 PM
Testing a speaker and output transformer Trutone A2-G
Hello murf! I merged the threads. Please do not start new threads regarding the same radio. Take care, - GaryGarySP — 10:21 PM
Philco 42-345 Restoration/Repair
Regarding picture 5 on page 1 of this thread this capacitor is #40 on scematics diagram - 4mF+4mF. Black wire is "-...Vlad95 — 09:01 PM
Philco 42-345 Restoration/Repair
That's a dual 4 MFD, red and green are both 4mfd and black is common negative. You should be able to see them in the pow...RodB — 08:58 PM

[-]
Who's Online
There are currently 329 online users. [Complete List]
» 2 Member(s) | 327 Guest(s)
AvatarAvatar

>