KT30

Beam Tetrode — B7G

MO Valve Co.

Known Equivalents & Substitutes

Y13CV3519

Electrical Specifications

Typical Operating

Anode Voltage (typical)Anode Voltage (typical)250V

Screen Voltage (typical)Screen Voltage (typical)250V

Grid 1 Bias VoltageGrid 1 Bias Voltage-12V

Anode CurrentAnode Current40mA

Screen CurrentScreen Current7mA

TransconductanceTransconductance3.9mA/V

Cathode Resistor (self-bias)Cathode Resistor (self-bias)260Ω

Output

Output PowerOutput Power2.7W

Load ImpedanceOptimum Load Impedance7,500Ω

Heater

Heater VoltageHeater Voltage13V

Heater CurrentHeater Current0.3A

Notes

13 V heater at 0.3 A — designed for series-string heater operation in battery receivers.
British 7-pin (M7A) base — an early British base type, not the later B7G miniature.
Very early beam tetrode design from 1934. Found in only 2 radio models at Radiomuseum.
Class A SE at Va=250V, Vg2=250V: Ia=40 mA, Ig2=7 mA, gm=3.9 mA/V, Rk=260 Ω, rl=7500 Ω, Pout=2.7 W.

Pin Layout — B7G

1Anode

2Screen Grid (g2)

3Control Grid (g1)

4