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

TH-3 bad power transformer
#1

Hello

I have a Transitone TH-3. The power transformer has a shorted high voltage secondary winding. The Philco part # is 32-7979M. Is this something I could try and repair. If not is there a replacement that someone may have for purchase or a universal transformer that would work.

Thanks

Troy
#2

The rubber insulation used on the leads of this power transformer contributed to its demise, no doubt. I've seen many 1939 Philco models that had rubber insulation on the power transformer leads; with evidence that the rubber melted, then dried out, then flaked off, causing the wires to short together.

I would go ahead and replace it. The original specifications are:

High voltage secondary: 410 volts center-tapped (205-0-205 V), 42 mA.
Filament: 6.3 V, 2A.

You'll need a vertical mounting transformer, which is easier to find than a horizontal mounting transformer.

Either a Hammond HX-269EX or HX-269GX will serve as a replacement. I think I would go with the HX-269EX; its high voltage secondary is 380 volts center-tapped (CT), compared to the 450 volt CT output of the 269GX. Too much B+ could upset the circuitry of the TH-3; causing squealing/oscillations, etc.

You can buy Hammond transformers from Radio Daze.

http://www.radiodaze.com/

--
Ron Ramirez
Ferdinand IN
#3

I have a Transformer, I bought a chassie for a antenna coil , it has a power transformer , contact me ,BILL




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-345 Restoration/Repair
In some cases the old paper caps can be replaced with ceramic caps, with values such as .001 uf, .005 uf, .01 uf, and ma...Arran — 06:50 PM
1949 Motorola 5A9M
Vlad; I would tend to agree, I only suggested the loop antenna connections since he was already looking at the end of...Arran — 06:18 PM
Philco 42-345 Restoration/Repair
Rod thank you for helping to understand the paper caps and offering the bumblebee caps. I have already ordered film caps...osanders0311 — 03:55 PM
1949 Motorola 5A9M
Bob, this is the wrong sequence to look for problems and setup circuits. Always start checking the signal path from the...Vlad95 — 12:19 PM
Philco J1720 stereo and record player with reverb
The above link takes you to the Delaware Valley Historic Radio club. They are not too far from you and may have sugg...klondike98 — 11:49 AM
Tucker Movie Prop car
Richard: Did you ever check with your friend? About once a year I try to verify if Mr Rhoades really worked on the r...WrenchMonkey — 09:22 AM
Philco J1720 stereo and record player with reverb
>>when turning the knobs This is very broad. There are knobs for tuning and knobs for volume, and possibly f...morzh — 07:36 AM
1949 Motorola 5A9M
Thx Arran, I will check the antenna connections. Right now the loop is alligator clip connected to the chassis since you...klondike98 — 03:58 AM
1949 Motorola 5A9M
Bob; I was just thinking that maybe the 1R5 tube doesn't like being operated at 1.2 volts on the filament, though you...Arran — 12:56 AM
Philco J1720 stereo and record player with reverb
So I just purchased a Philco J1720 stereo and record player. That has some static when turning the knobs. Wanted to see ...PhilcoJ1720 — 12:26 AM

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

>