RCA 630TS Need IF Coil - IF Osc. Issue

I'm new to vintage TV restoration and this is my first post to this forum.
I'm currently restoring an RCA 630TS television and have just completed
a full re-capping (minus the micas) and some resistor replacement. The
chassis powers up fine and all voltages are close to what is stated in
the service manual voltage chart.

I had to perform a complete video IF alignment because the 3rd IF coil
was destroyed by mice. I was able to replace the damaged coil with a
Merit TV-102 and I was able to achieve a decent swept video response
with one exception, I'm getting RF interference on channel 7 that seems
to be fed back through the tuner. The Merit coil did tune broadly during
alignment and I suspect possible IF parasitic oscillation.

Does anyone know what might be going on here? I would like to locate
a stock replacement 3rd IF coil, RCA p/n 71426. Suggestions on where
I might locate one is most appreciative. To rule out a possible source of
external RF interference, other televisions in my house do not exhibit
the Ch. 7 interference on the same coaxial line. Thanks for any and all
assistance with this most perplexing problem.

Mark G.

[Old1625]

Although I haven't seen such a thing you need perhaps in that app to examine the varmint-chewed part for a possible tertiary winding in that coil that may have served as a trap for this malady you mention. They do have them in TV sets to trap the sound subcarrier. There may be one for each the high and low VHF bands sprinkled throughout the IF chain...

Sometimes in my dim dark past of doing old TV resto the best solution in IF chain work was to reconstruct the old coils rather than to try to make the aftermarket "hammer-to-fit" coils do the same job with satisfactory results. Usually in my experience I was sometimes happy, and mostly not with the results--sorry to say.... Something makes me want to remember that in a lot of TV sets I've encountered that the final IF can is sometimes critically designed...

At the very most I may have provided a nugget of a hint at your solution, but I am tending to doubt it. At least I have bumped you back up the scale for wiser heads to get a look-see.

Been a long time (try over 30 years) since I've delved in TV resto, so please forgive me if I preach to the choir here. Good luck in your sleuthing, and may others more well-informed apply here.

[bgadow]

You can try emailing Moyers

http://www.moyerelectronics.com/

as they have lots of NOS parts. I know the 630 can be a little flaky as far as tuning. Mine isn't perfect but I don't feel up to doing an alignment.

Thanks for the info Bryan. With the two 6BK4s you must be ready to work
on a color chassis or two. I'm keeping my eye open for an early one.

-Mark G.