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) - 5 Average
  • 1
  • 2
  • 3
  • 4
  • 5

46-1201 model 128 restore and question
#16

If resistor 27 is completely open, that will certainly cause a problem, but then you would have no voltage at all on the plate (pin 2). You can try replacing it and see what happens.

I would also try to trace out the wiring to pin 7 and see why there is voltage present there. Pins 4 and 7 should be connected together inside the 7C6 tube, so there should be no voltage between them.
#17

Sooooo, apparently i've made a faux pas. The last 3 tubes i mixed up. Sorry about that. The readings seem much better now. Here's the new readings.

   
#18

That's much better. Now it looks like resistor 27 is really the problem. You only have a half a volt on the plate pin 2 where there should be 55 V.

An open resistor 27 would be the cause since it should supply plate voltage to pin 2.
#19

+1 for Mondail, smarter than me. The new measurements really focus on that tube and #27 resistor. Now the voltage is going low, prior readings were going high.
Jerry

A friend in need is a pest!  Bill Slee ca 1970.
#20

Yup, replaced #27 resistor and lots of volume! had to remove the cone to get all the grit and metal particles out of the center but sounds great now except for some buzzing and humming depending on the station tuned in. Could this just be an alignment issue? I still have some resistors i want to replace because they're over 10% off.




Users browsing this thread:
[-]
Recent Posts
philcorepairbench.com - shadow-meter
Anyone know of a way to recover these files from the repair bench? Thanks. fenbach — 11:16 PM
Philco model 38 code 121 not receiving signal.
That's true. Of course If I were to get a vtvm I'd probably have to sink money in to it to get it working right. Probabl...Stormlord5500 — 08:44 PM
Philco model 38 code 121 not receiving signal.
A DMM is good enough. One rarely has to measure indictance, but if you do, short of getting a serious LCR meter (I hav...morzh — 07:35 PM
Testing a speaker and output transformer Trutone A2-G
You guy's are right on. I found a broken wire on the speaker plug that I replaced and all is well now. Have better volu...murf — 03:43 PM
Philco model 38 code 121 not receiving signal.
I need to get a vtvm. I think that little component tester is just more accurate. Plus it shows the inductance which is ...Stormlord5500 — 03:07 PM
Philco model 38 code 121 not receiving signal.
I use a pair of Mastercraft brand DMMs from Canadian Tire, from what I read most of those DMMs use the same main chip re...Arran — 02:36 PM
Philco model 38 code 121 not receiving signal.
Thank you sir. Yes I feel good and also relieved because this one's been weighing on me a bit.Stormlord5500 — 11:18 AM
Philco model 38 code 121 not receiving signal.
It feels good don't it? Good luck on the rest.Paul Philco322 — 11:06 AM
Philco model 38 code 121 not receiving signal.
I've reinstalled the coil. Now IT'S ALIVE!!!!!! I fired up my TinySA on signal generator mode and set it to 1400Kc and ...Stormlord5500 — 11:01 AM
Philco model 38 code 121 not receiving signal.
Yes, Walmart, right up there with Fluke.RodB — 11:00 AM

[-]
Who's Online
There are currently 2097 online users. [Complete List]
» 2 Member(s) | 2095 Guest(s)
AvatarAvatar

>