[Amps] 4cx800a

[gdaught6 at stanford.edu]

Let me throw my experience(s) into this.  Not God's word, just my own personal 
experience.

Svetlana made the GU-74B (I don't want to fuss with Cyrillic letters here) which was  
used in some commercially built amps.  Svetlana USA offered the tube as a 
4CX800A, not 4CX800, not 4CX800A7.  I used a 4CX800A in my Dentron MLA-
2500B conversion (QST, May 1996).  I may still have a tube or two around.  I have 
the data sheet (Svetlana) for the 4CX800A which has been posted on :

http://www.g8wrb.org/tetrodes/

Since Svetlana USA got out of the business, and the Svetlana (St. Petersburg) quit 
making them, the 4CX1600B (which I also used in an amplifier.  See ARRL 
handbooks 1999-2004.  Since publication, the 4CX1600B is unobtanium.  The 
4CX800A may have the same status.  There are a few (fewer and fewer!) GU-74B's 
around, and prices are climbing. 

Moral:  if K6GT wrote about it, it's about to become extinct!

73,

 George T Daughters, K6GT
CU in the California QSO Party (CQP)
October 2-3, 2010