GI-7B, (GI-7BT)

Originally designed for military vehicles and tanks the rugged GI-7B (GI-70B) microwave triode operates as an oscillator and an amplifier in continuous-wave or pulsed mode with anode modulation in the centimetric and decimetric wavelength ranges.

The triode is available in two variants differing in the type of cooling: the GI-7B with a heat sink for forced air cooling and the GI-70B with no heat sink for other systems of cooling.
Note:  The GI-7BT has the same electrical characteristics but is mechanically more robust with a larger diameter ceramic element.

Cathode: indirectly heated, oxide-coated.
Envelope: metal-ceramic.
Cooling: forced air.
Height: 110.5 mm with heat sink, 97 mm with no heat sink.
Diameter: 65 mm with heat sink.
Mass: at most 330 g with heat sink, 170 g with no heat sink.



KP cathode and heater; P - heater; C - grid; A - anode

Gi-70B (No Heat Sink)

Vibration loads:
frequencies, Hz 5-600
acceleration, m/s² 59
Multiple impacts with acceleration, m/s² 343
Ambient temperature, °C -60 to +100
Relative humidity at up to +40 °C, % 98
Electrical Parameters
Heater voltage, V 12.6
Heater current, A 1.8-2.05
Mutual conductance (at anode voltage 1.2 kV, grid voltage change by 1 V, anode current 150 mA), mA/V 20-26
Penetration factor (at anode voltage 1.3 kV, anode voltage change 200 V, anode current 150mA), % 1.2-1.8
Operating point (negative grid voltage at anode voltage 1.3 kV, anode current 150 mA), V 12.5-7.5
Interelectrode capacitance, pF;
input 10-12.2
output 0.055-0.095
transfer 4-5.2
Warm up time (at anode voltage 400 V), s, at most 90
Output power:
in CW operation (at anode voltage 1.05 kV, anode current 300 mA, wavelength 18.5 cm), W, at least 30
in pulsed operation (at peak anode voltage
9 kV, anode current 7.5 A, wavelength 10 cm, 1/pulse duty factor 1,400-150, pulse duration 3-10 µs),kW, at least
Output power over 650 h of service, W, at least 24
Limit Operating Values
Heater voltage, V 12-13.2
Anode voltage, kV:
in pulsed operation 9
instantaneous value in CW operation 5
DC in continuous operation 2.5
DC with cold cathode 3
Grid voltage, V:
instantaneous value in continuous operation -400 to +80
in pulsed operation -900 to +600
Cathode current, A:
r.m.s. value 0.6
DC component under conditions of class  without modulation 0.4
instantaneous value under conditions of class  without modulation 1.25
Anode current (DC component in pulsed operation), A 7.5
Dissipation, W:
anode 350
grid 7
Wavelength, cm 9
Cathode heating time, s 90
Pulse duration, µs 10
Temperature, °C:
anode end face 200
anode heat sink 160
cathode lead 100
grid lead 200
outer ceramic parts 250
Resistance in grid circuit, kOm 10

Averaged Anode Characteristic Curves:
Uf = 12.6V

Averaged Anode-Grid Characteristic Curves:
Uf = 12.6V

Averaged Characteristic Curves Showing Oscillator Output Power versus Anode Voltage in ContinuousWave Generation:
L = 18.5cm
Averaged Anode Characteristic Curves
Averaged Characteristic Curves:
Uf = 12.6V;
_____ anode;
_ _ _ grid-anode;
Pa max


Averaged Pulse-Operation Characteristic Curves:
Uf = 12.6V; t = 4µs; frequency 350 imp/s;
_____ anode;
_ _ _ grid-anode


Averaged Characteristic Curves:
Uf = 12.6V;
_____ anode-grid;
_ _ _ grid