GU73 B
TETRODE
The GU73B tetrode is used for singlesideband power amplification at frequencies up to 250 MHz.
GENERAL
Cathode: indirectly heated, oxidecoated.
Envelope: metaltoceramic.
Cooling: forced air.
Height: at most 150 mm.
Diameter: at most 101 mm.
Mass: at most 150g.
K  cathode; P  heater; C1  grid 1; C2  grid 2; A  anode; I  contact surfaces
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  580 
acceleration, m/s²  25 
Multiple impacts with acceleration, m/s²  118 
Linear loads with acceleration, m/s²  88 
Lowest permissible ambient temperature, °C  60 
Relative humidity at up to +40 °C, %  9598 
BASIC DATA Electrical Parameters 

Heater voltage (AC or DC), V  27 
Heater current, A  4.555.15 
Anode voltage, kV  1.7 
Grid 2 voltage, V  250 
Negative grid 1 bias voltage, V  1840 
Negative cutoff voltage, V, at most  120 
Anode current, A  1.5 
Grid 2 current, mA  130 
Mutual conductance, mA/V, at least  65 
Gain coefficient (grid 1 grid 2)  37 
Voltage level of combination frequencies of third and fifth orders (at anode voltage 3 kV, grid 2 voltage 300 V, anode current 750 mA, grid 2 current at most 110 mA), dB, at most  30 
Warm up time, s, at most  210 
Oscillatory power under conditions of class AB 
2.5 
Interelectrode capacitance, pF:  
input  190 
output  27 
transfer  0.2 
Limit Operating Values  
Heater voltage, V  24.727.3 
Anode voltage (DC), kV  3 
Grid 2 voltage (DC), V  325 
Negative grid 1 voltage, V  150 
Anode dissipation, kW:  
singlesideband signal amplification  2.5 
TV signal amplification  3.5 
Grid 2 dissipation, W  35 
Grid 1 dissipation, W  5 
Cathode current (DC component), A  2.2 
Anode current (instantaneous value), A  7 
Operating frequency, MHz  250 
Temperature at anode, stem and seals, °C  200 
Averaged Anode Characteristic Curves:
U_{f} = 27V; U_{g2} = 300V
Averaged Grid and AnodeGrid Characteristic Curves:
U_{f} = 27V; U_{g2} = 300V;
_____ anode;
_ _ _ grid 2;
_ . _ grid 1
Averaged GridAnode Characteristic Curves:
U_{f} = 27V; U_{g2} = 300V;
————— (I_{g2});
   (I_{g1})