The HF-140 (AKA 211-D) is a 100 watt triode with a mu of 12 and a maximum frequency for full power of 15 MHz made by Amperex. Length = 9.12" Diameter = 2.62" Max voltage = 1250 Max current = 210 ma Fil voltage = 10 Fil current = 3.25 amps GOTO INDEX