GI25
TRIODE
The GI25 triode is used as an oscillator with pulsed anode and grid keying in the centimetric and decimetric wavelength ranges.
GENERAL
Cathode: indirectly heated, oxidecoated.
Envelope: titaniumceramic.
Height: at most 37 mm.
Diameter: at most 25.5 mm.
Mass: at most 25 g.
KP  cathode and heater; P  heater; C  grid; A  anode
OPERATING ENVIRONMENTAL CONDITIONS  
Vibration loads:  
frequencies, Hz  20600 
acceleration, m/s²  59 
Multiple impacts with acceleration, m/s²  490 
Single impacts with acceleration, m/s²  2,940 
Linear loads with acceleration, m/s²  490 
Ambient temperature, °C  60 to +100 
Relative humidity at up to +40 °C, %  98 
BASIC DATA Electrical Parameters 

Heater voltage, V  6.3 
Heater current, A  0.891.01 
Mutual conductance (at anode voltage 250 V, grid voltage change —1 V, anode current 30 mA), mA/V  1830 
Operating point (negative grid voltage at anode voltage 250 V, anode current 30 mA), V  1.04.5 
Negative cutoff voltage (at anode voltage 250 V, anode current 200 mA), V, at least  10 
Interelectrode capacitance, pF:  
input  3.55.5 
output, at most  0.08 
transfer  1.62.3 
Warm up time, s, at most  45 
Peak output power (at pulse 1/duty factor 1,000, pulse duration 1µs, peak anode voltage 2.8 kV, peak anode current 2.5 A, wavelength 7.5 cm), W, at least  900 
Peak output power over 1,000 h of service, W, at least  700 
Limit Operating Values  
Heater voltage, V  66.6 
Anode voltage, kV:  
DC with grid keying  1.3 
peak value (with pulse duration at most 3 µs)  3 
Peak grid voltage, V  120 to 0 
Grid voltage in pulsed grid keying mode, V  80 to 0 
Peak anode current (with pulse duration at most 3 µs), A  2.8 
Peak grid current, A  0.7 
Overshoot of modulating pulse leading edge (with duration at most 0.2 µs), %  20 
Dissipation, W:  
anode in pulsed operation  12 
grid  0.25 
Wavelength (with anode modulation), cm, at least  5.5 
Pulse 1/duty factor, at least  800 
Cathode heating time, s  60 
Envelope temperature, °C  200 
Averaged Characteristic Curves in Pulsed Operation:
U_{f} = 6.3V; t = 1µs; pulse frequency 1,000 imp/s;
_____ anode;
_ _ _ gridanode
Averaged Characteristic Curves in Pulsed Operation:
U_{f} = 6.3V; t = 1µs; pulse frequency 1,000 imp/s;
_____ anodegrid;
_ _ _ grid