GU66A
TRIODE
The GU66A triode is used for power amplification at up to 30 MHz in groundedgrid or groundedcathode circuits in stationary RF transmitters.
GENERAL
Cathode: directly heated, carbonized thoriated tungsten.
Envelope: metalceramic with ring leads of cathode and grid.
Cooling: forced (water for anode, air for stem).
Height: at most 420 mm.
Diameter: at most 183 mm.
Mass: at most 16 kg.
OPERATING ENVIRONMENTAL CONDITIONS  
Ambient temperature, °C  10 to +55 
Relative humidity at up to +25 °C, %  98 
BASIC DATA Electrical Parameters 

Filament voltage (AC or DC), V  13.5 
Filament current, A  200250 
Negative cutoff voltage (at anode voltage 10 kV, anode current 0.1 A), absolute value, V, at most  300 
Mutual conductance (at anode voltage 2 kV, anode currents 6 and 12 A), mA/V  95125 
Gain coefficient (at anode voltage 4 kV, anode current 8 A)  3953 
Output power (at anode voltage 10 kV), kW, at least  100 
Interelectrode capacitance, pF:  
input, at most  160 
output, at most  3 
transfer, at most  55 
Limit Operating Values  
Maximum filament voltage (AC or DC), V  14 
Filament starting current, A  360 
Anode voltage (DC), kV  10 
Cutoff voltage (instantaneous value), absolute value, kV  1.5 
Dissipation, kW:  
anode  60 
grid  1.3 
Operating frequency, MHz  30 
Temperature at stem and metaltoceramic seals, °C  200 
Averaged Characteristic Curves:
U_{f} = 13.5V;
_____ anodegrid;
_ _ _ grid
Averaged GridAnode Characteristic Curves:
U_{f} = 13.5V