6AL5
The 6AL5 (European type EAA91) is a high-perveance dual diode vacuum tube with a 6.3 V, 0.3 A heater.
The 12AL5 (European type HAA91) is the same but has a 12.6 V, 0.15 A heater. Both have a B9A (Noval) miniature 9-pin base.
The 6AL5/12AL5 serves as the as the "disconnect diode" in the timebase circuit of many tube-era Tektronix scopes starting with the the 511 in the 1940's and continuing through the 1960's in sweep plug-ins such as the 3B2 and other plug-ins such as Type C/Type CA.
Data and Links
- System: max. 420 V peak, max. 9 mA, 2.5 pF
- RCA 6AL5 Datasheet (PDF)
- 6AL5 / 12AL5 @ radiomuseum.org