717A

Small Signal Pentode — Octal

Western Electric

Known Equivalents & Substitutes

VT-269CV3594

Similar Tubes (Not Drop-In Compatible)

384A

Earlier Western Electric pentode from which the 717A was derived; different base and ratings

Similar sharp-cutoff RF pentode on B7G base with higher gm (5.1 mA/V) and different pinout — not a drop-in

713A

Electrically identical pentode but in 7-pin octal bakelite base — not pin-compatible due to different base

Electrical Specifications

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)180V

Screen Voltage (max)Screen Voltage (max)120V

Cathode Current (max)Cathode Current (max)10.1mA

Typical Operating

Anode Voltage (typical)Anode Voltage120V

Screen Voltage (typical)

Notes

Known as the 'little doorknob' due to its miniature metal-shell envelope (34 mm diameter, 37 mm tall excluding pins).
Suppressor grid (g3) is internally connected to the metal shell (pin 1) which serves as a base shield.
Pins 3 and 5 are both cathode connections — both should be grounded for proper RF shielding.
The 713A and 717A are electrically identical; only the base construction differs.
Manufactured by Western Electric and Tung-Sol during WWII in large quantities for radar service.
Datasheet typical operating conditions use Va=120V and Vs=120V (equal plate and screen voltages).
Grid voltage for Ip = 10 µA (approx. cutoff): -9 V.

Pin Layout — Octal

1Suppressor Grid (shell/base shield)

2Heater

3Cathode

4

References