GS36b 
Tetrode 
The GS36B tetrode is designed for power amplification in distributedgain
amplifiers and singlesideband signal amplifiers at frequencies up to 75 MHz, and for
power amplification at up to 500 MHz in RF equipment. The GS36b tetrode
is generally considered to be similar to the 4CX400A.

GENERAL  
Cathode: indirectly heated, dispenser, oxidecoated.  
Envelope: metalceramic.  
Cooling: forced air.  
Height, mm, at most:  67 
Diameter, mm, at most:  51 
Mass, gm, at most  220 
A  anode; I  contact surfaces; C1  grid 1; 1 & C2  grid 2; 2, 4, 6, 8  cathode; 3, 7  heater 
ENVIRONMENTAL OPERATING CONDITIONS  
Vibration loads: 

frequency, Hz  1600 
acceleration, m/s²  100 
Multiple impacts with acceleration, m/s²  400 
Single impacts with acceleration, m/s²  1,500 
Linear loads with acceleration, m/s²  25 
Ambient Conditions:  
Temperature, °C  60 to +85 
Relative humidity at up to +35 °C, %  98 
NOMINAL ELECTRICAL PARAMETERS  
Heater voltage, V  6.3 
Heater current, A  2.15 
Mutual conductance (V_{a} = 1KV, V_{g2} = 325V, I_{a} = 400mA, change in V_{g1} = 2.5V), mA/V:  26 
Anode current (I_{a}) with V_{a} = 350V, V_{g2} = 325V, A:  >0.4 
Negative bias (V_{g1}) with V_{a} = 1KV, V_{g2} = 325V, I_{a} = 400mA, V:  722 
Negative cutoff bias (V_{g1}) with V_{a} = 2KV, V_{g2} = 325V, I_{a} = 20mA, V:  60 
input capacitance, pF  24 
output capacitance, at most, pF  7 
transfer capacitance, pF  <0.08 
Warm up time, s:  <90 
AB_{1} Output power, V_{a} = 2KV, I_{a} < 25mA, V_{g2} = 325V, I_{g1}<2x10^{3} mA, Freq. 0.11.0 MHz, W:  >250 
3rdorder energy relative to carrier, V_{a} = 2KV, V_{g2} = 325V, dB:  30 
5thorder energy relative to carrier, V_{a} = 2KV, V_{g2} = 325V, dB:  30 
Designed Tube Life (hours)  >1000 
ELECTRICAL PARAMETER LIMITS  
Heater voltage, V  66.6 
Heater current, A  2.953.35 
input capacitance, pF  1830 
output capacitance, pF  59 
Maximum CW Anode voltage (V_{a}), KV:  2.1 
Maximum Instantaneous value Anode voltage (V_{a}), KV:  4 
"Maximum" Control Grid voltage (V_{g1}), V  60 
Maximum Screen Grid voltage (V_{g2}), V  325 
CW cathode current (I_{c}), A:  0.4 
Anode Dissipation, W:  400 
Screen Grid (G2) Dissipation, W:  8 
Control Grid (G1) Dissipation, W:  0.2 
Temperature at envelope (hottest point), °C  200 
Frequency, MHz:  <500 

