CAP installation question - Videokarma.org TV - Video

toolguy · #1 01-13-2013, 04:07 PM

Hey everyone, it's been awhile since I've been here but I got side tracked by two other projects and the warm weather enjoying them. At any rate, I finally ordered all my CAPs for my 1955 GE resto.

Now I've installed many caps in my time from my pinball and arcade game restos, but these caps are a little different looking and I want to make sure In install them correctly.

In my experience, caps matter in what direction they are installed. My question is with the yellow cap in the pic (not my pic BTW) how do I tell what direction to install it?

With some of these yellow caps I got, the one lead is off set, but others it's not. So does the off set lead mean positive?

Is there a general rule such as install the new cap with the writting facing the banded end of the old cap?

Could someone please let me know? Thanks!

vts1134 · #2 01-13-2013, 04:13 PM

These caps are non-polarized, it doesn't matter which direction you install them. Electrolytic capacitors are a different story.

N2IXK · #3 01-13-2013, 04:37 PM

The replacement can go in with either polarity.

The banded end on the old caps denoted the "outside foil", which was usually connected to lower impedance side of the circuit. This somewhat improved the shielding/reduced hum in sensitive circuits.

If you are dealing with really sensitive circuitry (high gain audio preamps), it is possible to determine which end is which using a scope, but for recapping a TV chassis, it generally isn't worth the effort:

http://www.aikenamps.com/OutsideFoil.htm

toolguy · #4 01-13-2013, 05:05 PM

Ok I see.

I did nte the band on the old caps, and then like I said on most of mynew caps, one of the leads is off set from the middle. I also noticed on the first old cap I looked at, it too has one lead off set and was on the banded side.

I suppose this off setting, is just a manf quality issue then and as you said, the caps are non-polarized.

This wil be my first TV resto, so I'm looking forward to it. I already have all known good tubes and the picture tube is good and shows a full pic. I just did not want to run it long without doing a cap kit first.

toolguy · #5 01-13-2013, 04:26 PM

Alright, excellent!

I wondered about that but did not want to assume. Now I know.

Thank you very much!

ctc17 · #6 01-14-2013, 11:51 PM

Not a bad idea to check those yellow chinese caps before you put them in. I have found a few shorted ones and one or two off value like they were mis labeled.
I wont even use that trash anymore. I either used disk caps or the red NTE ones. No problems with those yet.