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

40-180 Output Transformer
#1

The audio output transformer on my 40-180 looks like it's been getting rather warm so I decided to replace it as long as I'm recapping the set.  I went with a Hammond 125C universal push pull transformer but I'm not sure that I understand the wiring diagram correctly. It appears that I would connect the secondary to pins 4&6 to get 12,800 impedance with an 8 ohm speaker.
The existing transformer appears to only have one primary wire coming from the power transformer. The Hammond has 3 wires on the primary side, a red, a blue, and a brown wire.  Not sure how that works ?
 
Here's a link to the transformer;  http://www.hammondmfg.com/125.htm 
 
And the schematic info;  http://www.nostalgiaair.org/PagesByModel...013332.pdf
#2

Hello Tucker,
Blue and brown go to each of the 41 output tubes red goes to the po wer supply 2 and 4 go to 8 ohm speaker.
#3

Well, I just looked at the 4 wires under the existing output transformer and they are ;

Black - goes to pin 2 of a 41 tube

Tan - goes to pin 2 of the other 41 tube

Black/Tan striped - goes to a terminal strip lug that splits off to pin 2 of the 7C6 tube and pin 3 of one of the 41 tubes and it also connects to one of the filter caps.

Bare wire - goes directly to the speaker.

I'm wondering if I wouldn't use the red wire for this radio ?
#4

Got to use the red wire it goes to pin 3 of the 41. With out it you won't have any hv on the plates of either 41 tube

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 think I’m missing something, the existing transformer has 4 wires and the replacement has 5 wires. Does the red wire replace the striped wire ? And does one of the wires to the speaker get connected to the same place the red wire gets connected to ?
#6

Hi Tucker,
Red wire takes the place of the Black and Tan wire, you should have 2 wires that go to the speaker.
Forrest




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
An attempt to remove the Field Coil from a G speaker
So, Q1. Does anyone know where to get the spider. Q2. If there is no such place, what material is best? I doubt tin is...morzh — 09:43 PM
An attempt to remove the Field Coil from a G speaker
Arran The oxidation seems to go deep, a few layers. The break starts right there, but then it will occur on every la...morzh — 07:35 PM
An attempt to remove the Field Coil from a G speaker
Mike, This is just a thought, the are on the coil where the verdigris (green oxidation is) I wonder if that is where ...Arran — 06:32 PM
An attempt to remove the Field Coil from a G speaker
Mike; I've made a one or two spiders by using some card stock, and a razor blade, it took more then one try but they ...Arran — 05:48 PM
Philco 91 Restore Code ??
I wondered about that. Wish there was some place local to get this stuff.dconant — 04:20 PM
Philco 89 indicator light.
Bending the lamp bracket (moving the lamp, that is) can possibly change the shape of the pointer a bit, but not its loca...morzh — 04:01 PM
Philco 91 Restore Code ??
Because the usable power rating of it then is (3,200/20,000)*25W= 4W. Maybe a tad more due to the mass, but not much. Yo...morzh — 03:59 PM
Philco 89 indicator light.
Thank you Dan, that was the trick. I kept trying to rebend the lamp bracket but that wasn't doing anything to help.Jim Dutridge — 02:18 PM
Philco 91 Restore Code ??
20K 25 watt. I thought it was a 20 watt at first.dconant — 01:37 PM
My Philco 37-116 Restore
Nah, too much and not that important.morzh — 01:33 PM

[-]
Who's Online
There are currently 4961 online users. [Complete List]
» 3 Member(s) | 4958 Guest(s)
AvatarAvatarAvatar

>