GI-70BT (original box)

The GI-70BT (ГИ-70БТ rus.) triode is used for continuouswave or pulsed operation with anode modulation, as an oscillator and an amplifier. The triode is available in two variants differing in the type of cooling: the GI-7BT with a heat sink for forced air cooling and the GI-70BT with no heat sink for other systems of cooling.
Forced air cooling 24 м³/h.

Stamp of technical control department of the manufacturer “ ОТК “ 

GI – letters defining the type of tube: GI – generator pulse;
70 – the number of the ordinal number of the development of this type of tube;
B – a letter indicating the type of forced cooling: B – air;
T – design of the product.

Technical specifications:

• Heater voltage: 12.6V
• Heater current: 1.8A – 2.05A
• Mutual conductance (at anode voltage 1.2 kV, grid voltage change by 1V, anode current 150 mA): 20mA – 26mA
• Operating point (negative grid voltage at anode voltage 1.3kV, anode current 150mA): 12.5V – 7.5V
• Interelectrode capacitance: 10pF – 12.2pF
• Interelectrode output: 0.055pF – 0.095pF
• Interelectrode transfer: 4pF – 5.2pF
• Warm up time (at anode voltage 400V): at most 90 s.
• Output power in CW operation (at anode voltage 1.05kV, anode current 300mA, wavelength 18.5 cm): at least 40W
• Output power in pulsed operation (at peak anode voltage 9kV, anode current 7.5A, wave length 10 cm, 1/pulse duty factor 1 ,400 – 150, pulse duration 3 μs – 10 μs): at least 12kW
• Output power over 650 hours of service: at least 32W

 Limiting performance:

• Heater voltage: 12V – 13.2V
• Anode voltage:
• in pulsed operation 9kV
• instantaneous value in CW operation: 5kV
• DC in continuous operation: 2.5kV
• DC with cold cathode: 3kV
• Grid voltage:
• instantaneous value in continuous operation -400V to 80V
• in pulsed operation: -900V to 600V
• Cathode current:
• r.m.s. value 0.6A
• DC component under conditions of class В without modulation: 0.4A
• instantaneous value under conditions of class В without modulation: 1.25A
• Anode current (DC component in pulsed operation): 7.5A
• Dissipation anode: 350W
• Dissipation grid: 7W

Operating time not less than 1000 hours.