CT-100 S/N B8002601 is Operational

[Tim]

Hi folks and thanks for the coils Terry.

The repaired field neutralizing pot seems to be holding OK.

I have had some time to work on it and I resolved the purity problem. I discovered that when I installed the fuse I had put the coil wire on one side of the fuse and the pot on the other. The potential difference across the 3 ohm fuse meant that there was always current flowing through the purity coil, even when the pot was full ccw. Moving the wire allowed the purity to be adjusted. I have to remove the CRT again so I did not dial it in 100% but it is very good.

Then I went on to convergence and I found that, after much twiddling, I cannot get the top and bottom as close as I would like. Blue will not converge with the green and red. I have attached a shot of what it looks like. I also have to have the focus control full CW and feel like i'd like it to go a very slight bit more. Focus voltage is 3kv at this setting. I'd be interested in others experiences in this area.

The only other major issue is that depending on content, the HV swings from about 16KV to 20KV. The focus voltage sometimes drops to zero when the HV is minimum and the screen becomes a massive blur. It then recovers when the screen content becomes darker. The focus and HV regulator tubes are NOS and the HV shunt regulator tests good but I do not have another to sub it. Could this be possibly caused by driving it direct from cable and the front end is being overloaded? The test generator also causes this same problem. I have not yet tried another source. Any comments on this phenomena would be appreciated.

The set is very watchable from a distance and I am pleased with the progress so far. I have attached some screen shots. My camera is not accurately displaying the color of the bars though. The Yellow looks more yellow on the screen and the blue is darker than the camera shows. I also cannot see the moire' on the screen that the camera is picking up.