Posts: 14
Threads: 6
Joined: Jul 2023
City: Sammamish
State, Province, Country: Wa
Hi all, I'm restoring a Model 41-610 which was missing it's electro-dynamic speaker assy model 36-1524. I found a Fairbanks-Morse with similar specs at a reasonable price as a suitable replacement. My problem is figuring out which of the 4 wires coming out of the chassis connect to which of the 4 wires from the speaker assy (output trans and field coil). The schematic is all I have but I struggle with trying to trace wiring and the connector is not specifically called out on the schematic. Any suggestions on how to decipher? I VERY MUCH APRECIATE ANY help. Thanks.
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
The wires from the original speaker: the field coil will have connection to the rectifier's filament and both electrolytic caps. Then you take care of the output xfmr wiring.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 14
Threads: 6
Joined: Jul 2023
City: Sammamish
State, Province, Country: Wa
OK, that does clear things up a bit. I think you helped get me on the right track. I know I have to get this step right before attempting any power or risk destroying all the work and $$ I've put it so far.
Thank you! Much appreciated.
Posts: 7,295
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
I'm pretty sure on that set the output transformer is mounted to the chassis and is wired the 41 tube's plates and screen grid. The secondary and field coil are connected thru the speaker plug. Two of the connection should show a low resistance against each other (opt 2ndy). Like a an ohm or two. The other two should show a short the one or the other filter cap. Have Fun!
https://philcoradio.com/library/download...20Book.pdf
GL
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
(This post was last modified: 08-31-2023, 04:50 PM by
Radioroslyn.)
Posts: 14
Threads: 6
Joined: Jul 2023
City: Sammamish
State, Province, Country: Wa
Oh my gosh, you're right. I've lost my mind. Yeah, the OT is in the chassis, I stare at it every day and I highlight it on the schematic then I promptly forget it all when I see an OT attached to the speaker. Thanks so much for pointing that out. I definitely do not need to hook up two OTs.
I believe I get the field coil connections now but forgive me, I didn't quite follow the second part of your description. Were you saying the remaining two of the 4 speaker plug pins should show a short to one or the other filter cap?
Lord help me, I'm definitely going to slow walk this one....
Posts: 16,476
Threads: 573
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Even easier, if the xfmr is on the chassis.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 7,295
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Sorry 1 pin should show a short to the + side of 91 and the other a short to the + side of 43A. That's where the fc connects. The other two are the vc.
The diagram is not drawn properly it looks like plate and fc connection are connected thru the plug but they aren't. I wouldn't know this except I have a 41-300 which the same set up. OBTW check the resistance from the screen grid to the plates of the 41's to see if the pri is good. Sometimes 1/2 or both sides are open.
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
(This post was last modified: 08-31-2023, 09:50 PM by
Radioroslyn.)
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
