Russian tetrode tube GU-82B
Svetlana
eq. 4CX800A But more powerful .
I have two GU-82B .
This tube is better and more powerful than tube GU-74B .
Russian tetrode tube GU-74B and GU-82B are direct replacements for use in some of the best-built RF power amplifiers, including Alpha 99, 91B, 8100; ACOM 1000, 1006, 1010, 2000A. Fully equivalent to the modern 4CX800A tube.
http://www.cqham.ru/forum/showthread.php?23094-%C0-%E1%FB%EB%E0-%EB%E8-%EE%ED%E0-(%C3%D382%C1)
http://www.cqham.ru/forum/showthread.php?19049-ACOM-1000-%ED%E0-%C3%D3-82%C1/page4