GU72
TETRODE
The GU72 tetrode is used for singlesideband power amplification at frequencies up to 100 MHz in RF transmitters.
GENERAL
Cathode: indirectly heated, oxidecoated.
Envelope: glasstometal.
Height: at most 115 mm.
Diameter: at most 67 mm.
Mass: at most 320 mm.
1, 4, 8  cathode and heater; 2, 5, 9  grid 1; 3, 7, 10  grid 2; 6  heater; A  anode; I  contact surface
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  10200 
acceleration, m/s²  39 
Multiple impacts with acceleration, m/s²  343 
Single impacts with acceleration, m/s²  1,470 
Relative humidity at up to +40 °C, %  98 
BASIC DATA Electrical Parameters 

Heater voltage, V  26 
Heater current, A  0.851.05 
Mutual conductance (at anode voltage 300 V, grid 2 voltage 250 V, grid 1 voltage change ±2.5 V, anode current 270 mA), mA/V  1523 
Gain coefficient (grid 1grid 2) (at anode voltage 300 V, grid 2 voltage 200250 V, anode current 270 mA)  712 
Negative cutoff voltage, V, at most  220 
Interelectrode capacitance, pF:  
input, at most  37 
output  510 
transfer, at most  0.1 
Output power under conditions of class AB (at anode voltage 800 V, grid 2 voltage 300 V, anode current 68 mA), W, at least  70 
Output power over 1,000 h of service, W  26 
Limit Operating Values  
Heater voltage, V  2227.2 
Anode voltage, kV:  
DC  1.3 
peak value  1.8 
Grid 2 voltage, V  700 
Negative grid 1 voltage, V  250 
Cathode current, mA:  
DC component  250 
peak value  750 
Dissipation, W:  
anode  85 
grid 2  15 
grid 1  1 
Operating frequency, MHz  100 
Warm up time, s  2 
Envelope temperature, °C  250 
Averaged Anode Characteristic Curves:
U_{f} = 26V; U_{g2} = 300V
Averaged Anode Characteristic Curves:
U_{f} = 26V; U_{g2} = 400V
Averaged AnodeGrid and Grid Characteristic Curves:
U_{f} = 26V; U_{g2} = 300V;
————— (I_{a});
   (I_{g2});
— • — (I_{g3})
Averaged AnodeGrid and Grid Characteristic Curves:
U_{f} = 26V; U_{a} = 400V;
   (I_{g2});
— • — (I_{g3})
Averaged GridAnode Characteristic Curves:
U_{f} = 26V; U_{g2} = 300V;
_____ (I_{g2});
   (I_{g1})
Averaged GridAnode Characteristic Curves:
U_{f} = 26V; U_{g2} = 400V;
_____ (I_{g2});
   (I_{g1})