On Mon, 05 Jan 2009 09:54:36 -0500, Scott Dorsey wrote:

Richard Knoppow wrote:
The 50L6 is NOT a relative of the 6L6. It is a pentode
power tube with 10 watts of plate dissipation compared to 19 watts for a
6L6. The 6L6 puts out about 2.5 times the power when operating as a
single tube Class-1A aplifier. Other characteristics are also different.

Yeesh! That is not good at all! That is a very misleading number in
that case.

What about the 25L6 then? I have pitched a lot of 25L6 tubes over the
years because they showed low transconductance compared with a 6L6.
--scott

AFAIK the numbering -- other than the filament voltage, and other than
suffix letters -- is almost completely arbitrary; any similarities in
functions between similarly numbered tubes in a marketing, rather than an
engineering, decision.

Even then, as Richard pointed out, the filament voltage sometimes isn't,
and a 'G' variant of a metal tube often has different interelectrode
capacitances than the parent tube or the 'GT' variant.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html