GM4B
TETRODE
The GM4B tetrode is used in highvoltage regulators
GENERAL
Cathode: directly heated, carbonized thoriated tungsten
Envelope: glasstometal.
Anode cooling: forced air.
Height: at most 287 mm.
Diameter: at most 144 mm.
Mass: at most 6 kg
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  10120 
acceleration, m/s²  59 
Ambient temperature, °C  65 to +85 
Relative humidity at up to +40 °C, %  9598 
BASIC DATA Electrical Parameters 

Filament voltage (AC or DC), V  5 
Filament current, A  3543 
Resistance of unheated cathode, Om, at most  0.012 
Negative grid 1 voltage (at anode current 0.8 A, anode voltage 1.5 kV), V  2240 
Grid 2 voltage, kV  1 
Cathode emission current (at peak anode and grid voltage 300 V), A, at least  8 
Grid 2 current (at anode voltage 1.5 kV, anode current 1 A), mA, at most  75 
Inverse grid 1 current (at anode voltage 9 kV, anode current 1 A), µA, at most  100 
Mutual conductance (at anode voltage 1.5 kV, anode currents 0.8 and 1 A), mA/V  1927 
Gain coefficient (grid 1 grid 2) (at anode voltage 1.5 kV, grid 2 voltages 1 and 1.2 kV, anode current 1 A)  1015 
Interelectrode capacitance, pF:  
input, at most  85 
output, at most  16.5 
transfer, at most  0.5 
Limit Operating Values  
Filament voltage (AC or DC), V  4.55.25 
Filament starting current, A  60 
Anode voltage, kV  9 
Anode voltage over 0.1 s at overload up to 30 kW, kV  20 
Grid 2 voltage, kV  1.2 
Dissipation, W:  
anode  9x10³ 
grid 2  80 
grid 1  50 
Warm up time, s  20 
Temperature, °C:  
anode  250 
glass and glasstometal seals  150 
Averaged Characteristic Curves: U_{f} = 5V; U_{g2} = 800V;
_____ anode;
_ _ _ gridanode;
—— • —— P_{a max}
Averaged Characteristic Curves: U_{f} = 5V; U_{g2} = 1kV;
_____ anode;
_ _ _ gridanode;
—— • —— P_{a max}
Averaged Characteristic Curves:
U_{f} = 5V; U_{g} = 1,2kV;
_____ anode;
_ _ _ gridanode;
—— • —— P_{a max}
Averaged Characteristic Curves:
U_{f} = 5V; U_{g2} = 800V;
_____ anodegrid;
   grid 1;
_ . _ grid 2
Averaged Characteristic Curves:
U_{f} = 5V; U_{g2} = 1.2kV;
_____ anodegrid;
_ _ _ grid 1;
_ . _ grid 2
Averaged Characteristic Curves:
U_{f} = 5V; U_{g2} = 1.2 kV;
_____ anodegrid;
_ _ _ grid 1;
_ . _ grid 2