Sub for a 25XP22

[kvflyer]

Does anyone know if there is a sub for a 25XP22? I have my mom and dad's set from the late 60s. It was our first color set when I was in High School. The CRT reads very low on all three guns and when you elevate the filament voltage to 8 volts, it shows an H - K short. Also, it is the original kinescope and has a bad case of cataract. I think it a CTC-28.

Here is a thread that I started a long time ago on ARF:

http://www.antiqueradios.com/forums/...c.php?t=137346

Thanks!