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

Replacement output transformer for speaker conversion
#1

Hello all,

I recently acquired a model 20 speaker that I am planning on using for my model 70.  I have read the article on converting the 20 model speakers to use in both the 70 and 90 models.  I am searching for a new output transformer and wanted to ask if anyone that has made this conversion has a preferred brand or source for them?  I am wanting the new transformer to fit in the old transformer frame.  I was thinking of the 125ASE from radio daze. Any thoughts or concerns? 

Thanks
#2

Hiya Kid,
Well after consulting my 1947 RCA toob manual I find that plate load resistance for the push-pull 71A's is close the resistance the singe ended 47. Meaning that you could just rewire the xformer you've got. I won't hurt anything as the current is less with the 47 than the two 71A's. So what you would do is connect the plate of the 47 to one end of the primary and the HV to the other end. The center tap is left unused.

Terry
ps You didn't state if your xformer is good on the model 20 spkr ,I assumed that it is...
#3

Terry,

Thanks for the information! The transformer I have is good.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
6TPZ and 5TPO Radio Help
OK, so 18 and 19 as they should be. What is "everything else?" Try to be more specific in your descriptions:...morzh — 12:44 PM
6TPZ and 5TPO Radio Help
Yeah, I'm still on 5TPO. Sorry, my bad, points 1 and 2 should be points 18 and 19 (easy mistake  :think: )  X7 is shown ...R3Sons — 11:42 AM
Philco 40-120C Filament Wiring
Hi folks, I'm in the process of restoring a Philco 40-120C and I'm finding the wiring to be a bit puzzling. According to...bluecap — 11:28 AM
462ron
Hi Levi, here’s just a thought. Most radios run the oscillator higher than the dial setting. Say you set your radio to 1...462ron — 10:10 AM
1930s Stewart-Warner Tombstone Radio need help identifying model number
Another Update: I found a couple of damaged coils inside this radio that might have something to do with why this radio ...captainclock1988 — 10:51 PM
6TPZ and 5TPO Radio Help
If you are still on 5TPO, you lost me there. What X7? What Points 1 and 2?morzh — 08:37 PM
6TPZ and 5TPO Radio Help
Quick progress report: X7 is broken. Only one leg soldered, the other missing and the diode is cracked. I've replaced...R3Sons — 05:05 PM
6TPZ and 5TPO Radio Help
Oh...and you have electrolytic caps there. All need to go and be replaced.morzh — 04:36 PM
6TPZ and 5TPO Radio Help
Thanks, will do.R3Sons — 01:25 PM
1930s Stewart-Warner Tombstone Radio need help identifying model number
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM

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

>