[Amps] 3CPX800A7 Not Available (HAROLD B MANDEL)

[Jim Kearman]

From: "Tom Hix" <w4th at charter.net>

> Can someone tell me what makes a 3CPX800A7 is so much better than a plain 
> 3cx800a7 tube?

The P version has the same external dimensions but taller ceramic structure internally, so it can withstand higher anode voltage. Eimac recommends 2250 max for the 3CX, and 3500 max for the 3CPX. For direct substitution in an amp designed for the non-P version there probably isn't much advantage, but for new designs or upgrades the P version allows higher anode voltage, which can give better efficiency and require less drive power. 

73,

Jim, KR1S