Film vs. Ceramic Caps for higher voltages?

[toxcrusadr]

I'm working up to restoring my first old TV, a '50s Admiral radio/phono/TV console. At this point I just have a list of caps to replace, so I can't tell you where in the circuit I'm referring to, but in general:

Does it matter whether a cap is a film or ceramic type for most applications in TV circuits? Aside from the electrolytics, I'm talking about values like .047@600V, .033@1000V, .02@1600V. At voltages up to 400 or 600, film caps like orange drops are fine, but once you get into the higher voltages they get expensive. Can I replace films with ceramics if ceramic is cheaper?

IIRC, I have these on my parts list because the originals are films and I assumed they needed replacing. I'm guessing I left the ceramics as is for now.

[Kamakiri]

Funny you should ask, I just went through this with my '49 RCA. I used this style. Cheap, and worked great

http://www.digikey.com/product-detai...1353-ND/592929

[toxcrusadr]

Interesting...I was on Mouser (I actually understand their search engine, I remember not liking DigiKey as much) and was avoiding anything that looked like an SMD in the pics, so I probably looked right past these square types. Mouser did have a Cornell-Dub orange drop in this rating for 68 cents, but once you get to something like 0.2@1600V, the only film they list is not kept in stock and is $6.50 a pop.

Thanks for the tip.

[bob91343]

Ceramic capacitors are cheap and probably good enough for nearly any application.

They fall short when the capacitance tolerance is close, when the level is so low that piezoelectric effects are important, or in resonant circuits where there is substantial current through them.

[toxcrusadr]

Since I'm not sure where those conditions will occur in TV circuits, I think I will try to replace film caps with film caps, even if I have to use cheaper ones instead of Orange Drops in a few places. The set is not going to be a daily driver anyway.

[josephdaniel]

I believe one of the places they have problems in is the sweep circuits where they can cause geomorphology problems