GMI-27B

The GMI-27B (ГМИ-27Б rus.) pulse modulator tetrode is a glass-to-metal design with an indirectly heated oxide cathode and forced-air cooling. It is designed for use in pulse modulators with anode voltages up to 10kV and anode pulse currents exceeding 20A. It is manufactured in a glass-to-metal design with an external anode. It operates vertically.

Cooling – forced air:
– anode – 50 m³/h
– pin 20 m³/h

• Stamp of technical control department of the manufacturer ” ОТК “

Electrical Parameters:

• Filament current: 6,25 ± 0,5A
• Anode pulse current: min 20A
• Anode pulse current (at Un = 12V): max 18A
• Second grid peak current: max 2A
• First grid peak current: min 3A
• First gird negative cutoff voltage: max 500V
• Warm-up time: max 3 min
• Interelectrode capacitance, pF:
  – input 70±10
  – output 13±3
  – transfer max 1

Maximum Ratings

• Filament voltage: 12 .. 13,8V
• Anode voltage: 10kV
• Second grid voltage: 1kV
• First grid negative voltage: 0,8kV
• Firstgridpeakvoltage: 150V
• Anode dissipation: 250W
• Second grid dissipation: 15W
• First grid dissipation: 3W
• Peak cathode current at 1/duty factor up to 500: 34A
• Impulse duration: 30us
• Tube temperature: 150°C
• Operating ambient temperature range from -60°C to +85°C

Operating time not less than 1000 hours.