GU-72

TETRODE

The GU-72 tetrode is used for single-sideband power amplification at frequencies up to 100 MHz in RF transmitters.

GENERAL
Cathode: indirectly heated, oxide-coated.
Envelope: glass-to-metal.
Height: at most 115 mm.
Diameter: at most 67 mm.
Mass: at most 320 mm.

1, 4, 8 - cathode and heater; 2, 5, 9 - grid 1; 3, 7, 10 - grid 2; 6 - heater; A - anode; I - contact surface

BASIC DATA Electrical Parameters
Heater voltage, V	26
Heater current, A	0.85-1.05
Mutual conductance (at anode voltage 300 V, grid 2 voltage 250 V, grid 1 voltage change ±2.5 V, anode current 270 mA), mA/V	15-23
Gain coefficient (grid 1-grid 2) (at anode voltage 300 V, grid 2 voltage 200-250 V, anode current 270 mA)	7-12
Negative cutoff voltage, V, at most	220
Interelectrode capacitance, pF:
input, at most	37
output	5-10
transfer, at most	0.1
Output power under conditions of class AB (at anode voltage 800 V, grid 2 voltage 300 V, anode current 68 mA), W, at least	70
Output power over 1,000 h of service, W	26

Limit Operating Values
Heater voltage, V	22-27.2
Anode voltage, kV:
DC	1.3
peak value	1.8
Grid 2 voltage, V	700
Negative grid 1 voltage, V	250
Cathode current, mA:
DC component	250
peak value	750
Dissipation, W:
anode	85
grid 2	15
grid 1	1
Operating frequency, MHz	100
Warm up time, s	2
Envelope temperature, °C	250

Averaged Anode Characteristic Curves:
U_f = 26V; U_g2 = 300V

Averaged Anode Characteristic Curves:
U_f = 26V; U_g2 = 400V

Averaged Anode-Grid and Grid Characteristic Curves:
U_f = 26V; U_g2 = 300V;
————— (I_a);
- - - (I_g2);
— • — (I_g3)

Averaged Anode-Grid and Grid Characteristic Curves:
U_f = 26V; U_a = 400V;
- - - (I_g2);
— • — (I_g3)

Averaged Grid-Anode Characteristic Curves:
U_f = 26V; U_g2 = 300V;
_____ (I_g2);
- - - (I_g1)

Averaged Grid-Anode Characteristic Curves:
U_f = 26V; U_g2 = 400V;
_____ (I_g2);
- - - (I_g1)