Unsual type of transformer in Iskra CRT Tv.

[Bibdid]

I have just started servicing an old Iskra monochrome crt. This tv has inspection stickers from 1981, and is a bit older than what I typically deal with.

I've noticed multiple rectangular shaped transformers, at least what I think are (from board markings). They seem to have wicks at the top of them and I think can be adjusted with a screwdriver.

Does anyone know the name of these, and how they work? Have found little information through the markings.

[alfatv]

Re: Unsual type of transformer in Iskra CRT Tv.

These are adjustable inductors, part of processing circuit after TV tuner used to decode video and audio. The wicks are for holding ferrites in place, so they don't move over the time.
Is TV broken or just needs tune-up?

[Bibdid]

Re: Unsual type of transformer in Iskra CRT Tv.

Just needs a tune up!

Thanks for the information. I've never seen inductors like these before. I suppose they stopped using this type of inductor in the mid 80s?

[petehall347]

Re: Unsual type of transformer in Iskra CRT Tv.

dont go using metal tools the slugs will break ,shouldn't need touching anyway.

[alfatv]

Re: Unsual type of transformer in Iskra CRT Tv.

What kind of tune-up does it need?What exactly is wrong with it?
You need to find schematic or at least understand every adjustment before touching anything.
Some of them can be done only with special equipment.

[CapLeaker]

Re: Unsual type of transformer in Iskra CRT Tv.

Yes, and you need plastic tuning tools too. Stick a metal tool in there and it detunes in a hurry without turning anything. I broke one slug in one of my amplifier repairs, but I was lucky to find a proper replacement slug from a different radio with the same I.F. frequency.

[Bibdid]

Re: Unsual type of transformer in Iskra CRT Tv.

Just needs the yoke realigning. Circuitry is all fine. Was just a bit confused when I saw those inductors as I have never seen anything like that before.

Won't go tweaking them!

[Rajnhl]

Re: Unsual type of transformer in Iskra CRT Tv.

this type of coils are used in RF/IF section and video/color section, no need to adjust them for vertical section.
for vertical there could be 3 presets one for vertical hold (pic rolling vertically), 2nd vertical height and 3rd for vertical linearity.