Technical specifications: Filament voltage: 6.3 ±0.6V Filament curren:t 350 ±30mA Anode voltage nominal: 90 V Anode voltage limit: 300V Anode current of each triode: 10.5 ± 3mA Reverse grid current of each triode: 0.1μA Power dissipated by the anode, limiting: 1.5W Slope of each triode: 6.8 ±1.5mA/V Gain of each triode: 25 ± 7 Input impedance of the second triode: 1.9KOhm Equivalent tube noise resistance: 0.7KOhm Resistance in the cathode circuit of each triode for automatic bias: 125Ohm Resistance in the grid circuit limit: 1MOhm Operating time not less than 1500 hours.