GU84b 
Tetrode 
The GU84B tetrode is used for power amplification in
travelingwave and singlesideband signal amplifier circuits and as power amplifiers
in RF equipment up to 250MHz.

GENERAL  
Cathode: indirectly heated, oxidecoated.  
Envelope: metal ceramic.  
Cooling: forced air  96 m^{3} / hr ( just under 57 CFM) at 30mm H2O for 1600W dissipation  
Height, mm, at most:  115 
Diameter, mm, at most:  99 
Mass, Kg, at most:  1.5 


ENVIRONMENTAL OPERATING CONDITIONS  
Vibration loads: 

frequency, Hz  180 
acceleration, m/s²  50 
Multiple impacts with acceleration, m/s²  150 
Ambient Conditions:  
Temperature, °C  10 to +55 
Relative humidity at up to +35 °C, %  98 
NOMINAL ELECTRICAL PARAMETERS  
Heater voltage, V  27.0 
Heater current, A  3.7 
Mutual conductance (V_{a} = 750V, V_{g2} = 375V, I_{a} = 2A, change in V_{g1} = 1V), mA/V:  71 
Negative bias (V_{g1}) with V_{a} = 750V, V_{g2} = 375V, I_{a} > 2A, V:  1050 
Negative cutoff bias (V_{g1}) with V_{a} = 2KV, V_{g2} = 375V, I_{a} = 20mA, V:  150 
input capacitance, pF  102.5 
output capacitance, at most, pF  20.5 
transfer capacitance, pF  <0.2 
Warm up time, s:  <180 
AB_{1} Output, V_{a} = 2KV, V_{g2} = 375V, I_{g1} < 0mA, I_{g2} > 80mA, frequency 0.11 MHz, KW:  >1.5 
Designed Tube Life (hours)  >1500 
ELECTRICAL PARAMETER LIMITS  
Heater voltage, V  25.628.4 
Heater current, A  3.44.0 
input capacitance, pF  90115 
output capacitance, pF  1823 
Maximum CW Anode voltage (V_{a}), KV:  2.2 
"Maximum" Control Grid voltage (V_{g1}), V  150 
Maximum Screen Grid voltage (V_{g2}), V  400 
CW cathode current (I_{c}), A:  2 
Peak cathode current (I_{c}), A:  6 
Anode Dissipation, W:  2500 
Screen Grid (G2) Dissipation, W:  30 
Control Grid (G1) Dissipation, W:  1 
Temperature at envelope (hottest point), °C  200 
Frequency, MHz:  <250 
Averaged GridAnode Characteristic Curves: U_{f} = 27V; U_{g2} = 400V 
Averaged Anode Characteristic Curves: U_{f} = 27V; U_{g2} = 400V 
Averaged AnodeGrid and Grid Characteristic Curves: U_{f} = 27 V; U_{g2} = 400 V; _____ I_{a};    I_{g2} 