GU70B
TETRODE
The GU70B tetrode is used for linear power amplification and power amplification at frequencies up to 500 MHz in stationary and mobile RF equipment.
GENERAL
Cathode: indirectly heated, oxidecoated.
Envelope: metaltoceramic.
Cooling: forced air.
Height: at most 64 mm.
Diameter: at most 41.5 mm.
Mass: at most 150g.
1  grid; 2, 4, 6, 8  cathode; 3, 7  heater; 5  vacant; C1  grid 1; C2  grid 2; A  anode; I  contact surfaces
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  160 
acceleration, m/s²  20 
Multiple impacts with acceleration, m/s²  147 
Ambient temperature, °C  10to+55 
Relative humidity at up to +25 °C, %  98 
BASIC DATA Electrical Parameters 

Heater voltage (AC or DC), V  6 
Heater current, A  3.13.7 
Mutual conductance (at anode voltage 1.75 kV, grid 2 voltage 400 V, grid 1 voltage change ±2.5 V, anode current 200 mA), mA/V  1428 
Gain coefficient (at grid 2 voltages 400 and 350 V, anode current 200 mA)  918 
Negative bias voltage (at anode voltage 1.75 kV, grid 2 voltage 400 V, anode current 200 mA), absolute value, V  1428 
Negative cutoff voltage (at anode voltage 2 kV, grid 2 voltage 400 V, anode current 10 mA), absolute value, V, at most  60 
Interelectrode capacitance, pF:  
input, at most  29 
output, at most  7.5 
transfer,at most  0.06 
Output power under conditions of class AB_{1} (at anode voltage 2 kV, grid 2 voltage 400 V, grid 2 current at most 20 mA, at frequency 0.11 MHz), W, at least  250 
Output power under conditions of class Â (at heater voltage 6 V, anode voltage 1.9 kV, grid 2 voltage 400 V, anode current DC component 250 mA, frequency 500 MHz), W, at least  125 
AB_{1}, over 1,000 h of service, W, at least  200 
Relative level of combination components (at heater voltage 6 V, anode voltage 2 kV, grid 2 voltage 400 V),dB:  
thirdorder components, at most  30 
fifthorder components, at most  30 
Output power under condition of class 
Limit Operating Values  
Heater voltage (AC or DC), V  5.76.3 
Anode voltage, kV:  
DC  2.0 
instantaneous value  3.5 
Negative grid 1 voltage, absolute value, V  
150  
Grid 2 voltage (DC), V  400 
Cathode current (DC component), mA  360 
Dissipation, W:  
anode  350 
grid 2:  
at frequencies up to 250 MHz  8 
at frequencies above 250 MHz  6 
grid 1  2 
Operating frequency, MHz  500 
Temperature at the hottest point of envelope, °C  200 
Averaged Anode Characteristic Curves:
U_{f} = 6V; U_{g2} = 400V
Averaged AnodeGrid Characteristic Curves:
U_{f} = 6V; U_{g2} = 400V
Averaged Characteristic Curves:
U_{f} = 6V; U_{g2} = 400V;
_____ grid 2anode;
_ _ _ grid 1anode