ГУ81М

PENTODE
The GU-81M pentode is used in self-excited oscillation and power amplification circuits of RF equipment.

GENERAL
Cathode: directly heated, carbonized thoriated tungsten. Envelope: glass, with base. Height: at most 260 mm. Diameter: at most 202 mm. Mass: at most 1kg.

OPERATING ENVIRONMENTAL CONDITIONS
Ambient temperature, °C ............... -10to+55
Relative humidity at up to +25 °C, % ............... 98
BASIC DATA Electrical Parameters
Filament voltage, V .................. 12.6
Filament current, A, almost ................. 11
Mutual conductance (at anode voltage 2 kV, grid 2 voltage 600 V, anode current 200 mA), mA/V ........... 4.5-6.5
Gain coefficient (grid 1 - grid 2) (at anode voltage 2 kV, grid 2 voltages 600 and 500 V, anode current 200 mA) ........ 2.5-4
Bias voltage (at anode voltage 2 kV, grid 2 voltage 600 V), V .............. 116-160
Interelectrode capacitance, pF:
input ............. 25-32
output ............. 21-26
grid 1 -anode, at most ............. 0.1
grid 1-grids .............. 1-4
Output power (at anode voltage 2 kV, grid 2 voltage 600 V, bias voltage - 200 V, grid 1 drive voltage amplitude 300 V, anode current, at least 450 mA, grid 1 current at most 20 mA, grid 2 current, at most 220 mA), W, at least ........ 700

Limit Operating Values
Filament voltage, V ........... 11.6-13.4
Anode voltage, V:
at frequencies not above 6 MHz ............ 3
at frequencies not above 24 MHz ............... 2.5
at frequencies not above 50 MHz .............. 1.5
Grid 2 voltage, V ................ 600
Anode current (average value), A ............... 0.6
Grid 1 current (average value), A ............... 0.02
Grid 2 current (average value), A ............... 0.2
Dissipation, W:
anode ............. 450
anode (momentary dissipation) ............... 600
grid 2 ............. 120
grid 1 .............. 10
Envelope temperature, °C ............ 350