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

Restoring a 40-180
#1

Hello folks ,and thanks again for adding me. I am in the beginning stages of trying to revive a 40-180 for an old friend. His grandparents bought it new  ,and I'm really hoping I can get it working for him. I have just started replacing ,caps , resistors. I was told I could use larger value electrolytics ,so I'm using 22uf. 
I have a couple of questions here in the early stages.
#1: How can I safely remove the pushbutton ,and coil assemblies so I can access the components underneath?
#2: The OT on this unit really confuses me. I'm used to OTs on guitar amps. This one has primary wires ,but no secondary wires to the speaker. How does that work if I need a replacement? 

Thanks in advance ! Tom
#2

Can you post a photo showing the wiring for the output transformer from beneath the chassis? You should have four wires going to the speaker - two from the transformer for the voice coil and two from the power supply for the field coil.

Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/
#3

DaleHCook, There are only three wires ,and a ground I see on the OT.  Two go to the power tube plates ,and the center goes to 16uf cap ,and the field coil according to the schematic.


Attached Files Image(s)
       
#4

Actually, there are three insulated wires, a bare wire, and another bare wire which you may not see since it is soldered to the frame (side) of the audio output transformer (56).

The three insulated wires are the primary of the output transformer.

The bare wires (one you see, one you don't) are the secondary of the output transformer.

See partial schematic below.

   

--
Ron Ramirez
Ferdinand IN
#5

Thank you Ron. I thought it was just the one bare wire. (thought that was just a transformer ground) Would make more sense now.  I thought I checked those ,and the both showed ground ,but I'll check again.  I know the resistance reading on the primaries is low compared to what the schematic says ,but the leads are still soldered.


Attached Files Image(s)
   




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco Model 38-7: what caps & resistors do fail typically?
Since you stated earlier, you have a console 38-7XX.  They also had a 38-7T (table), and 38-7CS (chairside).  A very nic...GarySP — 01:18 PM
Part numbers to model cross
That I wouldn't know, but sometimes the radio document itself shows one, same as the capacitor cans' etc pinouts.morzh — 12:46 PM
Part numbers to model cross
Thank you morzh, that is exactly what I was looking for. Now , is there some where that shows pinouts for Philco power ...Jim Dutridge — 11:37 AM
Restoration of the Canadian General Electric A-87
Thanks for your help Michael. In fact, this video is only an intermediate result. Later I had to apply another tinting l...RadioSvit — 09:01 AM
Restoration of the Canadian General Electric A-87
Great job on the cabinet. PS. In the US notation, "kenotron" refers to specific type of tubes; we call re...morzh — 08:24 AM
Part numbers to model cross
This document has at least some tables of models and parts used. Example: Choke 32-7572, used in 604 radio. Search f...morzh — 08:19 AM
Restoration of the Canadian General Electric A-87
I also checked all the radio tubes on my Hickok 530 tube tester. The 5Z3 kenotron turned out to be faulty, all the other...RadioSvit — 08:02 AM
Restoration of the Canadian General Electric A-87
Well... While the varnish is drying up, I started repairing the chassis... Of course I started by replacing the pa...RadioSvit — 07:12 AM
Philco Model 38-7: what caps & resistors do fail typically?
Hello Martin, Welcome aboard our little community what great Model 38-7 Sincerely Richardradiorich — 12:30 AM
Philco Model 38-7: what caps & resistors do fail typically?
Welcome to the Phorum Martin. I count about 9 paper caps, the 3 electrolytic caps and 2-Y2 safety caps to replace th...RodB — 09:44 PM

[-]
Who's Online
There are currently 1493 online users. [Complete List]
» 1 Member(s) | 1492 Guest(s)
Avatar

>