RCA Magnetic Focus Issue
 

I have an RCA set with a KCS47 chassis that I've been working on. This is the first set I've had where I encountered a mechanical magnetic focus system. After my initial recap and general clean up I brought the set up on a variac and it had a nice bright raster. The focus didn't look too bad, but it was very hard to adjust. There was a lot of "gunk" on the metal sleeve that slides back and forth on the neck of the crt (16GP4) to adjust the focus. I decided to remove the magnet/focus assembly and clean it. The magnets are all glued in position on one end so they were not disturbed. I cleaned it up and put it back together. BIG SURPISE.....the focus is terrible now and adjusting the control does little or nothing to help. I've tried just about everything I can think of, but the focus is quite poor now.

I saw another thread on AK regarding another set with this same issue and the solution seemed to be to remagnetize the three magnets. Problem is....the specific instructions for doing so are kind of vague and I don't have access to a high amperage 24 volt DC power source.

Just wondering if anyone else has come up against this and found a different solution? Also wondering if anyone has a spare magnet assembly I might buy and try?

The set has a great picture, it's bright and stable, but very blurry.

Attached are a few pictures of the assembly from my set.

Thanks.
Bob

Bob:

See if you can move all the magnets closer to the CRT neck. It looks like there's some play in the assembly.

I remember the consensus on these is don't take them apart, once you do they no longer work right without remagnetizing them.

I have one sitting in front of me from a 47 that I scrapped, no telling if the magnets are any better but it's yours for postage if you want it.

Hi Don;
If you look closely at the second picture you can see that there is a depression in the metal where the magnets sit. They are all sitting in as close to the neck as the depression allows.
Bob

Correction Don...it's the third picture.....
Bob

Hi Eric;
I wish I'd read that "consensus" before I had the urge to clean this one up. I'll take you up on your offer, I'll have nothing to lose but the cost of postage.

I'll PM you my address.

Thanks!
Bob

I have a PM magnet assembly also, yours for postage, + I'll throw in the yoke.

Hi John;
Thanks...PM sent.
Bob