Digging into the CTC-9

[leadlike]

Well, my next step was to mess with the HV. After getting the spare crt installed, I noticed the HV was normal, but I noticed that I couldn't advance the HV beyond 20kv. The picture looked a bit out of focus as well.

The next day was a bit more humid, and on power up, I heard some spitting coming from the cage. Opening up the cage while under power showed some nice corona all around the 6BK4 cap and lead in. The rubber on the wire was all dried out, and the cap was very crumbly.

Well, the Zenith roundie had provided a good crt, why not some HV hardware, too? I pulled the RCA's lucite HV cup, too-as it was warped. Surprisingly, the Zenith's HV cup went right in-they were a perfect match! While the RCA's 6BK4 cap was like any other tube cap, the Zenith's is a massive insulated sleeve that covers the whole top half of the tube. The wire lead is also heavily insulated. With those in, I could ramp up the HV to just under 40 KV! Not that I kept it there.

Now I have a pretty well-functioning roundie. I can now dig into convergence and color balance. Any tips on these settings? What should HV be set to? Can I damage the crt by cranking up the Drive/G2 controls too high?