1953 Arvin 8213 Restoration

[Gleb]

I'd better install a single 10w resistor. BTW, why are you replacing all the resistors? Are they all out of tolerance?

[Crist Rigott]

Originally Posted by Gleb

I'd better install a single 10w resistor. BTW, why are you replacing all the resistors? Are they all out of tolerance?

Mostly. This chassis is proving out just like most of them. About 2/3 are clearly out of tolerance, 1/6 are just in tolerance, and the final 1/6 are within tolerance. So having 5/6 of the resistors out of or just with in tolerance, I change them all. The last thing I want to do is go back in and change a resistor that's causing problems in the future. Another thing, my 1W resistors cost a whooping 4 cents each from Mouser. Why take the chance with a 65 year old resistor?

[Notimetolooz]

About installing a 10W wire-wound for the group of three carbon, I would check the schematic to see how that resistor is used. The WW of course has a bit of inductance, so if it is used as a plate load in the video amp it could effect the flatness of the bandwidth. I've seen high wattage carbons used this way. Another place you don't want a WW is in the RF and IF circuits.

[dieseljeep]

Originally Posted by Crist Rigott

Mostly. This chassis is proving out just like most of them. About 2/3 are clearly out of tolerance, 1/6 are just in tolerance, and the final 1/6 are within tolerance. So having 5/6 of the resistors out of or just with in tolerance, I change them all. The last thing I want to do is go back in and change a resistor that's causing problems in the future. Another thing, my 1W resistors cost a whooping 4 cents each from Mouser. Why take the chance with a 65 year old resistor?

Some of those resistors look a little tired.
BTW, what procedure do you use to remove all the old leads and solder from the terminal strips? On occasion, I use a desoldering iron like used on PC boards.
As usual, amazing work!

[Crist Rigott]

Guys, here is the schematic of those 3 resistors. R131,R132, R133. Looks like I could use a wire wound resistor there...right?

[Gleb]

Originally Posted by Crist Rigott

Looks like I could use a wire wound resistor there

Yes you can use any type there; it's just a current limiter for the 2nd grid of the horizontal output tube (V23). It seems that three usual carbon resistors were simply cheaper than a single wirewound one.

[Notimetolooz]

I agree that a wire wound should be OK there. Seems odd the way they have the other side of C123 connected to the cathode instead of ground, as if there was some AC signal to be transferred from one to the other.

[Crist Rigott]

I installed the wire wound.

[Crist Rigott]

Originally Posted by dieseljeep

Some of those resistors look a little tired.
BTW, what procedure do you use to remove all the old leads and solder from the terminal strips? On occasion, I use a desoldering iron like used on PC boards.
As usual, amazing work!

I usually clip the component free leaving about 1/4 to 3/8 inch on the terminal strip. I then use solder wick to get as much solder off. Then I remove the old leads and again solder wick for final solder clean up. Then using a cut down acid brush, I brush with some acetone to clean off the old resin and make the terminal nice and clean. Then on to installing the new components.