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CV4501 / VX8121 reliable HF pentode

Size This valve measures 37x10mm overall and has a B8D base.

This valve is based on CV465. The EVS data states (and also for CV4505) "Because of production difficulties these valves should not be used in new design work except possibly for Missile Airborne applications when, if semi-conductors cannot be used, these are the first choice technically. Before any decision to use them is taken the M.O.A. production branch (LP(T)3) must be consulted." - the issue in question dates from the early 1960's.

Heater voltage 6.3V
Heater current 175mA
Max heater cathode voltage 100V
Max anode voltage (Ia=0) 350V
Max screen voltage (Ig2=0) 350V
Max negative grid voltage -100V
Max operating anode voltage 190V
Max operating screen voltage 190V
Max anode dissipation 1W
Max screen dissipation 0.4W
Max cathode current 12mA
Max grid circuit resistance (fixed bias) 250k ohms
Max grid circuit resistance (auto bias) 500k ohms
Max vibration (100 hours duration max) 5g
Max vibration (10 minutes duration max) 20g
Max shock (short duration) 500g
Max bulb temperature 165C
Minimum operating pressure 55mm Hg
Max ambient storage temperature -60 to +85C
Typical operating conditions, at Va=Vg2=100, Vg1=-1.4
Anode current 7mA
Screen current 2.2mA
Mutual conductance 5mA/V
Inner amplification factor 36
Capacitances (shielded)
Cin nom 4.5pF
Cout nom 2.7pF
Cag1 max 0.015pF


Lead Function
1 Control grid
2 Cathode, suppressor grid and shield
3 Heater
4 Cathode, suppressor grid and shield
5 Anode
6 Heater
7 Screen grid
8 Cathode, suppressor grid and shield

This file was last modified 23:10:30, Wednesday February 23, 2022