Posts: 90
Threads: 32
Joined: Oct 2011
City: Nipomo
State, Province, Country: CA
Hi,
I have a M Ward 62-319 that went dead on me. Doing some signal tracing I found the suspect 2nd I.F. transformer and in it an open coil. What do I do with this?? Finding an exact replacement would seem impossible. Does someone rewind these things for a reasonable cost? I removed the can so I could check the coil itself finding it open and no visible wire break.
Thanks,
Alan
Posts: 7,323
Threads: 270
Joined: Dec 2009
City: Roslyn Pa
Hi Alan,
Well there's a few choices. Hunt down a 465kc IF output transformer, try Play Things of the Past. Back in the day there where companies that make replacement IF transformers. Or If you have a slug tuned 455kc can you can use it but you'll need to open it up and change the value of the internal tuning caps to get it to resonate at 465kc. Or you could use a rf choke in place of the secondary coil and a small cap connected to the plate of the IF amp tube to coule the signal over to the diode plate. This will make the if rather broad and will loose some gain.
Some of the older Philcos have 460kc if cans you maybe able the get one to go up to 465
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 it!
Terry
(This post was last modified: 08-01-2016, 11:33 PM by
Radioroslyn.)
Posts: 90
Threads: 32
Joined: Oct 2011
City: Nipomo
State, Province, Country: CA
Thanks for the response Terry. So as long as it's a 465 kc it should do the job? And something close may be able to be tuned to 465 simply with the padders?
Alan
Posts: 7,323
Threads: 270
Joined: Dec 2009
City: Roslyn Pa
>So as long as it's a 465 kc it should do the job?
Your a little better off if it is a output transformer.The secondary has a low impedance to match the diode load. The input transformer secondary matches the grid of the IF amp tube which is high impedance.
> And something close may be able to be tuned to 465 simply with the padders?
That's why I mentioned the 460 and the 470kc Philco transformers.
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 it!
Terry
Posts: 28
Threads: 5
Joined: Aug 2016
City: Baton Rouge, LA
I have used this method of bypassing before; it works pretty well.
Here is the link to the writeup.
http://antiqueradios.com/chrs/journal/transformers.html
I have also carefully unwound the open coil, made the repair, and wound the wire back on.
Posts: 90
Threads: 32
Joined: Oct 2011
City: Nipomo
State, Province, Country: CA
(08-11-2016, 07:28 AM)kc5gym Wrote: I have used this method of bypassing before; it works pretty well.
Here is the link to the writeup.
http://antiqueradios.com/chrs/journal/transformers.html
I have also carefully unwound the open coil, made the repair, and wound the wire back on.
This looks great, I'll try it. Thank you!!
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
