flyback cooling

[Findm-Keepm]

Dave,

Before doing any mods, take a look at RCA's patent for the CTC12 HV cage - there are MANY safety concerns in the design of the enclosure. The US patent is 3273021.

Aside from what has already been proposed, I'd use a solid state HV rectifier, and make sure the regulator was a 6BK4C, not a 6BK4 or 6BK4A. The 6BK4 was the worst of the regulator tube designs - RCA pulled all of them when they brought out the 6BK4A (actually a Sylvania design, improved upon by RCA). The 6BK4C/6EL4A employs all of the improvements. It seems RCA, in an effort to improve the 6BK4's reliabilty, punched holes in the anode to help in outgassing of the tube at manufacture. The holes allowed the escape of X-radiation, so they inserted some baffles to mitigate the X-radiation (6BK4A) and later added both the denser (leaded) glass envelope and improved anode to further deal with the X-radiation threat that exists when the regulator tube is operated even marginally out of it's normal parameters (25KV, 1 to 1.3mA).

Hope this helps in some way,