alignment tool - plastic or metal?

[mraroid]

Quick question....

When I buy an alignment tool for the pots on my color classic, do they need to be plastic or some other non conductive material?  I have seen metal hex alignment tools.  But from my days as a kid adjusting my folks old vacuum tube TV, we always used plastic.

Is a non conductive alignment tool the best for the pots on our older Macs?

Thanks

jack

 

[Elfen]

Plastic.

In a few cases, the tool needs to go into a coil and adjust a ferret bead inside, manipulating the magnetic field around the coil. Using a metal tool will interfere with the magnetic field you are adjusting and it will never get properly adjusted.

The other reason, some of these adjustments needed have high voltages. Using a metal tool is just asking for trouble. You have not lived until you improperly discharge a CRT and get a 4KV Shock into your hand from it. The pain will be something you will never forget for the rest of your life and you will give that part a lot more respect than needed.

Finally, a metal tool can break these adjustment points. thing turn from one stop to another (except for coils, you can turn it until the bead comes out and then you need to put it back in!). If you turn it until it stops and it still needs more adjustment, its another component to find and replace, but mentally you will want to turn it until it breaks, and you will. With plastic tool, then you get to that point where it stops, and you try to turn it some more, the tool will bend, telling you to end it there.

 

[mraroid]

Elfen - you have saved my bacon yet again with your wise advice.  Now that I know the correct tool sizes, I will start looking for plastic.

all the best,

jack

 

[uniserver]

yup its kinda funny when i get a/b's in, and the ferrite core of the horizontal deflection coil is busted into about 9 pieces.

if i got a spare i just solder one in, those core's are usully so brittle I don't even try to unscrew a good one out, just desolder and change the whole thing.  most of the time i don't even mention it.

 

[Elfen]

If you hit the junk yards for old TV Sets, you can take their coils and use the beads from them if they are the same size. But that's a lot of TVs to go through.

 

[techknight]

Thats because the ferrite slugs get frozen in there, and they are brittle from the factory new... So you have to be very careful. I had a problem with that on my CC, i broke a slug inside the yoke which I have to match up and replace. 

I did the very same thing with my Zenith round CRT color set from the 60s, on the convergence board... Yuck. 

Penetrating oil would do wonders here. 

 

[uniserver]

i think it was trag that told me those core's can naturally break on their own.  hot/cold,  cracks can form, and they vibrate?

 

[uniserver]

i should use my meter to see µh value is.