GI6b 
Triode 
The GI6b triode is designed for use in microwave oscillator circuits with no external
feedback, providing continuous wave or pulsed operation with anode modulation in the
decimetric wavelength range. This tube was originally developed by the Germans during
W.W.II for selfoscillating radars, and it was copied by the Russians after the war for use
in radar, even as recently as the beginning of 1970's. The original tube designation
for the LD6 or GI6B was either LD11 /GI11B or LD12/GI12B, and it is useless as an amplifier
in the decimetric wavelength range because it has very high internal capacitive coupling 
three wires welded to the cathode going through holes in the grid and forming a capacitor to
the anode. The tube is being used quite successfully as an amplifier at 50MHz, however,
and some say it is useful even as high as 432MHz. As with most Russian power triodes,
the heat sink on the GI6b is removable.

GENERAL  
Cathode: indirectly heated, dispenser, oxidecoated.  
Envelope: metalceramic.  
Cooling: 24 m^{3}/hr forced air.  
Height, mm, at most:  with heat sink: 110.5 
without heat sink: 97  
Diameter, mm, at most:  with heat sink: 65 
without heat sink: 36.3+  
Mass, gm, at most:  with heat sink: 330 
without heat sink: 170 
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequency, Hz  5600 
acceleration, m/s²  59 
Multiple loads with acceleration, m/s²  342 
Single impacts with acceleration, m/s²  1,465 
Linear loads with acceleration, m/s²  490 
Ambient Conditions:  
Temperature, °C  60 to +100 
Relative humidity at up to +40 °C, %  9598 
NOMINAL ELECTRICAL PARAMETERS  
Heater voltage, V  12.6 
Heater current, A  1.925 
Mutual conductance (V_{a} = 1.2 kV, I_{a} = 150 mA, change in V_{g} = 1V), mA/V, at least  22 
Operating point (negative V_{g} with V_{a} = 1.3KV, I_{a} = 150mA), V  9 
input capacitance, pF:  11.1 
output capacitance, pF:  4.6 
transfer capacitance, pF:  0.25 
Warm up time (V_{a} = 400 V), at most  90 
Output power in CW operation (V_{a} = 1.05 kV, I_{a} = 300 mA, wavelength 18.5 cm), W  >30 
Output power in pulsed operation (at peak V_{a} = 9 kV, I_{a} = 7.5 A, wavelength 10 cm, 1/pulse duty factor 1,400150, pulse duration 310 ÷s), KW  >11 
Designed Tube Life (hours)  >650 
ELECTRICAL PARAMETER LIMITS  
Heater voltage, V  1213.2 
Heater current, A  1.82.05 
Mutual conductance (V_{a} = 1.2 kV, I_{a} = 150 mA, change in V_{g} = 1V), mA/V, at least  1826 
Operating point (negative V_{g} with V_{a} = 1.3KV, I_{a} = 150mA), V  612 
input capacitance, pF  1012.7 
output capacitance, pF:  45.2 
transfer capacitance, pF  0.20.3 
Maximum CW Anode voltage (V_{a}), KV:  2.5 
Maximum Instantaneous value Anode voltage (V_{a}), KV:  5 
Instantaneous value Grid voltage (V_{g}), V  300 to +80 
Maximum CW Cathode current (I_{c}), r.m.s./key down, A  0.6 / 0.4 
Anode Dissipation, W:  350 
Grid Dissipation, W:  7 
Temperature at anode lead, °C  200 
Temperature at radiator, °C  160 
Temperature at cathode leads, °C  100 
Temperature at grid leads, °C  200 
Temperature at external ceramic parts, °C  250 
Minimum wavelength in CW operation, cm  22 
Minimum wavelength in pulsed operation, cm  18 
Averaged PulseOperation Characteristic Curves: U_{f} = 12.6V; U_{g2} = 200 V; T_{imp} = 1 ÷s; frequency 1,000 imp/s; _____ anode;    gridanode 
Averaged PulseOperation Characteristic Curves: U_{f} = 12.6V; U_{g2} = 200 V; T_{imp} = 1 ÷s; frequency 1,000 imp/s; _____ anode;    gridanode 
Averaged Characteristic Curves Showing
Oscillator Output Power versus Anode Voltage in ContinuousWave Generation: U_{f} = 12.6V; L = 25cm;    (P_{a max}) 
Averaged Anode Characteristic Curves 
Averaged Characteristic Curves Showing Oscillator Output Power versus Anode Voltage in ContinuousWave Generation: U_{f} = 12.6V; L = 50cm;     (P_{a max}) 
Averaged AnodeGrid Characteristic Curves 