(!!) (Best used single #1) 5998 Tungsol branded IBM black plates used/good 1960 rattle inside base (75/74ma) 1-3% section balance Title: 5998 Tungsol

5998 Tungsol branded IBM black plates used/good 1960 in white box – rattle inside bas from dried glue particles – best triode section balance

1 section) 75ma Gm=12,700

1 section) 74ma Gm=12,800

Good Ma range 60-80ma

Good Gm range 10,000 – 12,000