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CV2659 / 3D21 beam tetrode

This valve measures 118x45mm overall and has an octal base

This is a beam tetrode intended for pulse modulator or blocking oscillator service

Heater voltage12.6 (series) or 6.3V (parallel)
Heater current850mA (series) or 1.7A (parallel)
Max peak anode current (a)5kV
Max DC anode voltage (b, c)3.5kV
Max screen voltage (c)850V
Max peak negative control grid voltage (a)220V
Max peak positive control grid voltage220V
Max anode dissipation15W
Max screen dissipation3W
Max control grid dissipation500mW
Max heater cathode voltage±150V
Max pulse length (d)10µs
Anode current (e)31.5mA
Screen current (e)2.5mA
Mutual conductance (e)5.2mA/V
Max acceleration (continuous operation)1.0g
Max shock (short duration)500g
Cin nom17pF
Cout nom10pF
Ca,g1 max1.2pF

(a) including transients
(b) with a max screen voltage of 400V and when no transients are present a max DC anode voltage of 4500V may be applied.
(c) series resistance must be inserted in the power supply to limit the DC short-circuit current to less than 500mA
(d) total pulse length in any 240µs period shall not exceed 12µs
(e) measured at Va=600VDC, Vg2=300VDC, Rk=825 ohms

The valve needs to be mounted vertically

1Heater centre tap
4Screen grid
6Control grid

CV2659 / 3D21