CTC-4 Director 21

[jr_tech]

Originally Posted by SwizzyMan

Here is what I am working with. Heavy interference and bad purity.

How is the dag on the outside of the CRT grounded? Perhaps there is some arcing that is causing the interference? A fair amount of surface area is needed where the ground connection is made to the dag. Learned this back in my "poor starving young engineer days" where all that we had for a color tv was a small group of 4s that were patched together well enough to sorta work on a rotating basis. One of mine got necked (sliding closet door accident) and all that I could get was a rebuilt 21FBP22. It took a bit of effort to get the jug grounded well enough to stop the interference streaks in the picture.

jr

[Tubejunke]

Originally Posted by jr_tech

Perhaps there is some arcing that is causing the interference?

My thoughts exactly as I looked at those screen shots. I’m by no means a color TV expert, but I do have a Zenith roundie that had the slightest arching in the HV cage. It was hardly audible, but that was exactly what the picture looked like. Turned out that the HV rectifier socket was fried. Replaced that and no problems. In addition, I think that set needs degaussing. Most of us aren’t lucky enough to have a real serviceman’s degaussing ring, so I just use my Weller soldering gun in the same manner that you would use the ring.

[Electronic M]

Originally Posted by Tubejunke

My thoughts exactly as I looked at those screen shots. I’m by no means a color TV expert, but I do have a Zenith roundie that had the slightest arching in the HV cage. It was hardly audible, but that was exactly what the picture looked like. Turned out that the HV rectifier socket was fried. Replaced that and no problems. In addition, I think that set needs degaussing. Most of us aren’t lucky enough to have a real serviceman’s degaussing ring, so I just use my Weller soldering gun in the same manner that you would use the ring.

I've got a real service degaussing coil and I've made spares....Allz you have to do to make one is find a decent sized 20" or bigger BPC set at the curb, steal it's degaussing coil, loop that 3 times around so it becomes a smaller coil ~12-14" in diameter, wrap it in electrical tape so it holds that form, and attach a cord.
...It will get hotter faster than a servicing coil, but one can get about a minute run time (plenty for most sets) out of it before it needs a cool. I made a thread on the process a while back.