Same octal pinout and similar beam tetrode characteristics, but 350B draws 1.6A heater current vs 0.9A for 6L6 — heater transformer must be rated accordingly
The 350A, 350B, and 367A have essentially identical static characteristics but differ in lead-out arrangement and basing.
Heater current is 1.6A — nearly double that of the 6L6 (0.9A). While the pinout is identical to the 6L6 family, the 350B is not a drop-in replacement in circuits designed for 6L6 heater current without verifying the heater supply can handle the additional load.
Maximum grid circuit resistance differs by bias type: 0.1 MΩ for fixed bias, 0.5 MΩ for cathode bias.
Developed by Bell Telephone Laboratories and manufactured by Western Electric for AT&T telephone system applications. The USN-CW-350B is the US Navy designation for this tube.
Pin Layout — Octal
1No Connection
2Heater
3Anode (Plate)
4
Socket-Compatible Tubes ⚠ Not electrically compatible