GU-81M

Pentode for application as power amplifier or oscillator in self-excitation mode.

General information:

Cathode: directly heated, carbonized thoriated tungsten.

Envelope: glass,with base.

Height: max 26 mm.

Diameter: max 202mm.

Mass: max 1kg

Electrical parameters:

Heater voltage V ................................................................ 12.6

Heater current, A ........................................................... 11

Mutual conductance (U_a= 2kV. U_grid2 = 600V, I_a=200mA), mA/V..........4.5-6 5

Gain (U_a= 2kV, U_grid2=600V and 500 V,I_a=200 mA)........................ 2.5-4

Bias voltage (U_a= 2kV, U_grid2=600V), V ................................................ 116-160

Interelectrode capacitance. pF:

input .................................................................................. 25-32

output ................................................................................ 21-26

grid 1-anode ...................................................... 0.1

grid 1-grid 3 ..................................................................... 1-4

Output power (U_a= 2 kV, U_grid2=600V. U_bias= - 200 V. U_grid1 (amplitude)=300V. I_a= 450

I_grid1=20mA,I_grid2=220mA) ........................................................................... 700

Limit operating values:

Filament voltage, V................................................................ 11.6-134

Anode voltage. V:

at frequencies under 6 MHz.............................................................. 3

at frequencies under 24 MHz......................................................... 2.5

at frequencies under 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

Power dissipation, W:

anode .............................................................................. 450

anode (peak value)............................................................ 600

grid 2.................................................................................. 120

grid 1.................................................................................. 10

Envelope temperature, °C 350