(!!) 7199 RCA Black Plates NOS around 1960 era (9/7.8ma)

7199 RCA Black Plates NOS around 1960

pentode section (9ma) Gm=6200

triode section (7.8ma) Gm=2000

Tested on TV-7D/U

73/50 pentode section

54/42 triode section

for: 

- Bogen BD-212
- Dynaco ST-70, SCA-35
- Ampeg B25, B25B
- Heathkit AA-111
- Stromberg Carlson
- Ampex Concerto 1961
- Scott LK 150