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

Philco 39-40 Voltage Readings Request
#1

Good morning, all. I just finished re-wiring a 39-30 Chassis Code 121 table set and will be firing it up today. I suspect the power transformer is bad, but would like to get
a set of voltage reading specs if anyone has them. They are not in the two service bulletins I have for this set. Anyone have something easy to use, short of having to pull the specs tube by tube from the site that has tube specs and base diagrams?

If it does test bad, anyone have a good transformer to sell? Looks like this one's been replaced by a close substitute many years ago already.

Regards,
Clarence
#2

Pull the 84 and measure the AC from pins 2 then 3 to the center tap of the HV winding. If they are very close, probably OK. With 84 removed do rest of tubes light up OK and transformer not getting hot? Maybe still OK, but filter capacitors at very least must be changed.
#3

codefox1 Wrote:Pull the 84 and measure the AC from pins 2 then 3 to the center tap of the HV winding. If they are very close, probably OK. With 84 removed do rest of tubes light up OK and transformer not getting hot? Maybe still OK, but filter capacitors at very least must be changed.

Hi, Codefox. All the electrolytic and paper caps were replaced. All resistors tested and/or replaced. Replaced all the rubber-insulated wiring (it was really bad). Even replaced the dial lamp (using one from my Studebaker's instrument lamps, which use a nearly identical socket).

I did some basic voltage checks, and got no voltage (with 84 out) to the heaters.
Put the 84 in, and no voltage to the heaters or plates.
No tubes lit at all.

Since it measures 70 Megs resistance on the primary, pretty sure the power transformer is toast. I posted a Wanted ad for one on the Phorum. I hope I can get one, since this set has a nice cabinet and I've redone all the rest of the insides. It's a keeper for myself--I've put about 150 hours into it but had fun doing it and learned a few things along the way.

Regards,
Clarence




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
The list of my radio & TV collection!
Hi Richard. Yes, we are waiting for warm weather. I have more than a dozen hulls waiting to be painted.RadioSvit — 11:06 AM
6TPZ and 5TPO Radio Help
Then it is even easier. Yep, my GE guide also says "Silicon".morzh — 09:43 AM
462ron
Mike, according to my ECG replacement guide, the AR107 & AR108 both cross reference to a ECG 123A as does a GE-10. T...462ron — 09:41 AM
Atwater-Kent 84, restoration.
The 66 Ohm filter in the 1st detector's plate circuit. Look in the early version sch. Here it is, the spiral that ma...morzh — 09:11 AM
6TPZ and 5TPO Radio Help
Ron yes, that was found. The problem is trying to find GE-10 for AR107/108. I could not find even mentioning of it. ...morzh — 09:06 AM
462ron
Your output transistor X6 cross references to a GE-3 transistor and I’ve used that before. There are a few here on eBay…...462ron — 07:58 AM
Atwater-Kent 84, restoration.
Mike; Where was this RF choke located? I remember seeing on a few sets that had detector-amplifiers ahead of the powe...Arran — 02:29 AM
6TPZ and 5TPO Radio Help
Thank you very much. I'll let you know how it goes.R3Sons — 11:00 PM
Atwater-Kent 84, restoration.
Hello mike, Nice job hopefully it works and I am sure it will. Sincerely Richardradiorich — 09:15 PM
The list of my radio & TV collection!
Hello Peter, I am glad you got the radios and I too have that same zenith in my collection ! I am also waiting for the...radiorich — 08:52 PM

[-]
Who's Online
There are currently no members online.

>