GU-81M (original box)

Description

The GU-81M generator pentode with direct-heated tungsten carbide cathode.

Designed to amplify power and generate high-frequency oscillations at frequencies up to 50 MHz with an output power of at least 700 W. The GU-81M pentode is used in transmitters, high-power stages of low-frequency amplifiers and in other radio engineering devices.

Socle special with 6 conclusions. Working position vertical, a socle down. Cooling air natural or forced.

Stamp of technical control department of the manufacturer “ ОТК “ 

Technical specifications: (at Un=12.6 V, Ua=2 kV, Uc2=0.6 kV, Ia=200 mA)

• Filament current: no more than 10.5A
• The current of the 1st grid is reversed (at Un=13.6V, Ua=3kV) no more than 50µA
• Permeability of the 1st grid relative to the 2nd grid (at Uс2=0.5kV and 0.6kV) 31.5±4.5%
• The steepness of the characteristic (when changing Us by 10V) 5.5 ± 1mA/V

Oscillatory power:

• at a frequency of 50MHz at Uc1=200V, Ia=600mA, Ic2=200 mA: not less than 400W
• at a frequency of 12MHz at Ua=1.kV, Ia=500mA: not less than 750 W

Limiting performance:

• Heating voltage: 11.8 – 13.5V
• Anode voltageat a frequency of 6MHz: 3kV
• Anode voltage at a frequency of 24MHz: 2.5kV
• Anode voltage at a frequency of 50MHz: 1.5kV
• Anode voltage at anode modulation, peak value: 5kV
• 2nd Grid Voltage: 0.6kV
• Voltage of the 2nd grid in an impulse: 1.2kV
• Power dissipated by the anode for a long time: 450W
• Power dissipated by the anode for 3 min: 600W
• Power dissipated by the 2nd grid: 120W
• Power dissipated by 1st grid: 10V

Operating time not less than 1000 hours.