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

Philco 76 output transformer #2848
#16

That's sort of an odd design for an output transformer, most of the ones I have seen have the secondary on the outside, not the primary.
Regards
Arran
#17

I tried my best to exact a copy of the original. I dont know that I want to do another. And I have yet to see it in action, so..

Stan
#18

Well I finally got my output transformer stitched up, and back on the speaker. To my surprise it works. I have yet to do the voltage checks, and I'm not real happy with some of the things I had to do in the end. This was my first, maybe the next will come out better. The big thing is, I did it, and it worked!
#19

Well, The radio seems to play ok, but voltage checks have me scratching my head. The voltages all seem to be a bit high(DMM), but I have more than double the listed plate voltage on the Detector tube, and the first AF tube. By the resistance chart things are almost spot on, and PT voltages are good. Tubes good. My new field coil, by the DC resistance is 3245ohm. My rewound OPT is the only thing I can think of that may not be exactly like it should be.
#20

The plot thickens how about the voltage on the 24A's plates? There are fed off of the same line.

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
#21

Keep in mind, these were taken with a DMM.

Stan


Attached Files Image(s)
   
#22

Would check #14 100k resistor. If drifted lower in value this will raise the voltage. Poor ground at #14. Weak 24A. Clean heater contacts on socket & tube (24A det). Just for grins you can try grounding the control grid (grid cap) and check the plate voltage. If the voltage drops to a more normal level you may have a open 2ndry on the rf coil or bad ground.

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
#23
Wink 

Thank you for that Terry. You have given me some things to look at. I am now unstumped, for now.Icon_smile

Stan




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
philco predicta
I found that where I have the 140v B+ there is 50v and the tuner receives 235v through the orange cablecgl18 — 04:14 PM
Philco 91 code 221
Chassis grounds thru rivets is another good place to look. Oh and the stator screws on the tuning cap where the leads at...Radioroslyn — 08:11 AM
Philco 91 code 221
Dirty tube pins and socket, cold solder joint, stray tiny strand of wire, clean the entire area around the oscillator tu...RodB — 08:43 PM
Philco 91 code 221
I have been restoring one of these sets and switched it on yesterday. It didn't exactly spring into life, but after a co...Philconut — 08:26 PM
Philco 50-925 antenna connections
That's super. Glad to hear you figured it out. Paul.Paul Philco322 — 11:11 AM
Philco 50-925 antenna connections
Hello Keith, great news !! Sincerely Richardradiorich — 02:14 AM
Philco 50-925 antenna connections
Finally, got the antenna fixed (repaired some broken wires) and have the radio playing. I've got four different schemat...keith49vj3 — 09:38 PM
1949 Motorola 5A9M
Bob, Nice radio.  I’ve not seen one before.  Keep us updated!Joe Rossi — 07:56 PM
Phioco 90 Power Transformer Wire Colors
Thanks for adding that information.klondike98 — 06:09 PM
Phioco 90 Power Transformer Wire Colors
Although I have used this site as a resource for a number of years this is my first post.   I am restoring a Model 90 si...vincer — 05:02 PM

[-]
Who's Online
There are currently 1462 online users. [Complete List]
» 1 Member(s) | 1461 Guest(s)
Avatar

>