I have a westinghouse wr-8 (same as RCA radiola 82)with a bad coil in one of the IF transformers. I have read a little about rewinding coils, but don't know where to begin. Anyone have any suggestions?

Hi Mark, I have done this before and its not to difficult. You will need to unwind the original and keep count of how many turns of wire you take off. If your really lucky the break is in the first few turns of the coil and you can just resolder it and away you go.
Its important that your new coil go back on the form in the same position as the original one so make note to its position.
Get yourself some magnet wire thats the same gauge as the original. Crazy glue a couple of fiber washers on the coil form so they will contain the new windings that you will be winding on to the form. You can make them from a cereal box or what ever you have laying around the house.
You can make up a jig to use your eletric drill to turn the form as you keep some tension on the wire with you thumb and a finger, go slow and just scamble wind the new coil and keep count so you get as close to the same number of truns you took off. Dont forget to leave an inch or two of wire off the start so you can attach it. When your done winding paint some of your wifes nail polish on to hold the windings in place.
Its not the easiest thing to do but it does work and I have done it a couple times now with success.
The other way is to find a junk chassis that has a good one and swap it out.

Greg

:I have a westinghouse wr-8 (same as RCA radiola 82)with a bad coil in one of the IF transformers. I have read a little about rewinding coils, but don't know where to begin. Anyone have any suggestions?

I've never tried it, but I read or saw on the web..that you can use a small cheap hand drill available at most HW stores. The crank hande usualy has about a 3:1 or 4:1 turns ratio. It's easier to keep track of turns I guess if you are doing it by hand. And easy to hold it in a vice to make the jig.

Hi

Like mentioned you can rewind IF Transformers. Before you start think of this. Radiola 82 uses a 175kc IF frequency. This requires a lot more turns than 455kc.

You could also add a resistor across the open winding. Then couple plate to grid with a small cap, 200pf or so..

Norm

http://www.nostalgiaair.org/PagesByModel/343/M0040343.pdf

I wrote about this 11 years ago:

http://antiqueradios.com/chrs/journal/transformers.html

:I've never tried it, but I read or saw on the web..that you can use a small cheap hand drill available at most HW stores. The crank hande usualy has about a 3:1 or 4:1 turns ratio. It's easier to keep track of turns I guess if you are doing it by hand. And easy to hold it in a vice to make the jig.

Yes Norm... you are so right...I've done it.
I think I've also suggested this fix several times here in the forum
As soon as I found your article months ago I tried it and it worked great.
The only real headache I had with it was that both my IF were shot ...and so I used the idea for both.
...But although it does work.. the selectivety and sensitivety are very poor then.
But for only one IF it works great!.

:Yes Norm... you are so right...I've done it.
: I think I've also suggested this fix several times here in the forum
:As soon as I found your article months ago I tried it and it worked great.
:The only real headache I had with it was that both my IF were shot ...and so I used the idea for both.
:...But although it does work.. the selectivety and sensitivety are very poor then.
:But for only one IF it works great!.
:

Norm: Thanks for the help. It helps to have an option other than rewinding the coil. However, if I do decide to try and rewind it, how do I know what gauge wire to use? Antique Electronic Supply sells 8 different sizes and it seems that I would have to guess between a couple of them.

I did want to say that I came up with somewhat of a fix for my open coil. I used my meter to locate windings up and below where the break is. Then I used a needle to carefully pull out a bit of the wire at these two places. Then I soldered a piece of wire from one to the other to bypass the break. It was successful and it worked when I fired up the radio. I was able to align it with fairly good results. I don't think my repair will be long term, though. There is a lot of noise if I tap on that IF can and some static occasionally when the radio is operating.
:Hi
:
: Like mentioned you can rewind IF Transformers. Before you start think of this. Radiola 82 uses a 175kc IF frequency. This requires a lot more turns than 455kc.
:
: You could also add a resistor across the open winding. Then couple plate to grid with a small cap, 200pf or so..
:
:Norm
:
:http://www.nostalgiaair.org/PagesByModel/343/M0040343.pdf
:
: I wrote about this 11 years ago:
:
:http://antiqueradios.com/chrs/journal/transformers.html
:
:
:
::I've never tried it, but I read or saw on the web..that you can use a small cheap hand drill available at most HW stores. The crank hande usualy has about a 3:1 or 4:1 turns ratio. It's easier to keep track of turns I guess if you are doing it by hand. And easy to hold it in a vice to make the jig.

If you rewind your transformer, congratulations. I hope you do, and I wish you all the best. Having all original looking parts inside of a radio can't be beat. However, there are tons of very ugly and unwanted 1950s and 1960s radios on eBay all the time. If you need an IF transformer, why not purchase one of these and take its transformers? Usually they are slug tuned, so they can be adjusted for a different frequency. However, they may not be efficient at a frequency other than what they were designed for. If you can get one of these to work in your radio, though, you can probably stash it inside of the radio's transformer can.

Thomas

Hard to find a 50's- 60's radio with a 175 kc IF. But good suggestion otherwise.

As I said before, most of these transformers are permeably tuned, and can be re-adjusted for a different frequency. They may not work terribly efficiently at a different frequency. Never-the-less, they can be re-adjusted. This may or may not prove to be a better solution than resistance/capacitance coupling.

Thomas

:Hard to find a 50's- 60's radio with a 175 kc IF. But good suggestion otherwise.

I will keep this in mind if all else fails. Thanks for the tip. Mark

:As I said before, most of these transformers are permeably tuned, and can be re-adjusted for a different frequency. They may not work terribly efficiently at a different frequency. Never-the-less, they can be re-adjusted. This may or may not prove to be a better solution than resistance/capacitance coupling.
:
:Thomas
:
::Hard to find a 50's- 60's radio with a 175 kc IF. But good suggestion otherwise.

I am not sure for what stage it is used, but I know that there is an aftermarket transformer, may be avail from AES, that is adaptable for use as an interstage transformer for radiolas. Possibly that will help

:I will keep this in mind if all else fails. Thanks for the tip. Mark
:
:
::As I said before, most of these transformers are permeably tuned, and can be re-adjusted for a different frequency. They may not work terribly efficiently at a different frequency. Never-the-less, they can be re-adjusted. This may or may not prove to be a better solution than resistance/capacitance coupling.
::
::Thomas
::
:::Hard to find a 50's- 60's radio with a 175 kc IF. But good suggestion otherwise.

Also, regarding using 1960s IF transformers, if you can't get one of those slug tuned transformers to go down to 175 KC by tuning the slugs, you can increase the values of the capacitors until the transformers will go down to the appropriate frequency. Some of these transformers have the capacitors in the base. In this case, just parallel with 100 to 500 pF (or there-abouts) capacitors until you can get the frequency you want.

Thomas