Two Stupid Questions

FrizzleFried

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(1) Battlezone centering mod instructions indicate a .1 uF capacitor to be used. I am not seeing a standard barrel type cap at that size... am I to assume that I am supposed to use one of those little squareish type caps?

(2) what is the band colors for a 220k resistor and what direction is it supposed to be installed in?
 
1) I never used a cap to center the monitor in my BZ. Normally they tell you to just disconnect the signal and then adjust it the dot, but I always adjusted it with the picture up so I could try to get the radar in the circle properly.

2) 220k-ohm = red red yellow gold - and it doesn't matter which way it's installed.

For other resistor value questions, bookmark this:

http://www.dannyg.com/examples/res2/resistor.htm
 
I am doing the BZ Centering pot mod... I'm adding two pots to the board to add adjustable centering. Atari implemented the feature but never populated the required spots (1 220ohm resistor, 1 .1 uf cap, and a 50K pot.

Now, I went to radio shack and bought 2 .1uf ceramic disk caps... they say they're up to 50WVDC... but they also had only ONE .1uf Metalized-Film Cap...which has a rating of 250WVDC.

Can I use the ceramics or am I going to have to acquire another metalized-film cap?

Does anyone know what voltage that area of a BZ uses? I do note that the metalized-film caps seem to be utilized in the SIZE circuit...

What is the difference between the two (other than max VDC)?

Thanks...

EDIT: Here is a link to the mod I am doing... page 25...

http://www.crazykong.com/tech/bw_vector_monitor_faq.pdf

EDIT: Another stupid question ... Are these two types of caps bi-polar? If not... how do I determine what is positive and negative?
 
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Looks like the circuit from the description should only have a 30V swing, so the cap you have should work. The cap will probably only see 15V at a time when you are adjusting the pot in either direction.


I just noticed your second question about the capacitor differences. The ceramic cap you have is probably a Z5U type which has a 22% to 56% tolerance rating. The metalized film caps are much better on tolerance and are usually rated between 1% and 10%. Doesn't look like your application requires that kind of tolerance. At least it should have been specified if it did.
 
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These Radio Shack parts will work for your application:

272-1053 Capacitor, .1 uf @ 250 volt axial

272-1069 Capacitor, .1 uf @ 50 volts radial

272-135 Capacitor, .1 uf @ 50 volts ceramic disk

271-1132 Resistor, 220 k @ half watt

You'll probably want to use the 272-1069 capacitor as it's the closest to what Atari would have used.
 
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