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Home | Products | High-Power Helix Travelign Wave Tubes (TWTs)
Peterson AFB photo.
High-Power Helix Traveling Wave Tubes (TWTs)

L3 Electron Devices manufactures a line of ring bar TWTs in UHF and L-Bands with output powers up to 200 kW. These TWTs are used in long-range array radars such as the FPS-108 Cobra Dane system, the PARCS space surveillance radar, U.S. and foreign shipboard surveillance radars, and airport surveillance radars.  Specifications on high-powered TWTs.

Frequency
Product
Number
Frequency
MHz
Output
Power
Peak
kW
Output
Power
Average
Watts
Cathode
Voltage
kV
Cathode
Current
Amps
RF Duty
Cycle
%
Basic
Electronic
Efficiency
%
L-4920 420-450 175 10,500 40 14.0 6 40
L-4922 1200-1415 140* 6,000 40 13.0 3.6 35
L-4923 1175-1375 175 10,500 42 14.0 6 33
L -4950 3100-3500 125 2,500 40 12.0 2 35
L-4966 1250-1350 155 6,000 40 14.5 3.6 36
L-4995 850-1050 150 6,000 40 15.0 3.75 32
*Peak power levels of 200 (kW) are available in this frequency range
Prime Power Considerations
Product
#
Cathode Volt. kV Cathode Cur. Amps Grid Drive Volt. V Grid Bias Volt. V Grid Cur. mA Heater Volt. V Heater Cur. Amps 1st Stage Col. Cur. kV 1st Stage Col. Cur. Amps 2nd Stage Col. Volt. kV 2nd Stage Col. Cur. Amps
L-4920 40 14 1,300 -750 25.0 28 4 -12 12 -5 2
L-4922 40 13 1,250 -750 10.0 28 4 0 12.8 N/A N/A
L-4923 42 14 1,200 -750 14.0 28 4 -9 10 -3 4
L-4950 40 12 1,200 -750 10.0 28 4 0 11.8 N/A N/A
L-4966 40 14.5 1,400 -750 14.0 28 4 0 14.3 N/A N/A
L-4995 40 15 1,300 -750 14.0 28 4 0 14.8 N/A N/A
Electron Beam Focusing
Product # Method Solenoid
Volt. V
Solenoid
Cur. Amps
Slenoid Resistance
Ohms
Max Prime
Power Watts
Max DC
Intercept Cur. mA
Max RF
Intercept Cur. mA
Coolant
L-4920 INTEGRAL 72 13 5 1200.0 250 1250 WATER
L-4922 INTEGRAL 80 13 4.5 1100.0 200 400 WATER
L-4923 EXTERNAL 20 20 N/A 500.0 100 200 WATER
L-4950 INTEGRAL 50 13 5 1000.0 200 500 WATER
L-4966 INTEGRAL 80 13 4.5 1100.0 100 150 WATER
L-4995 INTEGRAL 80 13 4.5 1100.0 100 350 WATER
ExtendedRF Parameters
Product # Small
Signal
Gain dB
AM
Noise dB
PM
Noise dB
Noise Poer
Output
dBm/MHz
2nd
Harm. dBc
Insertion
Loss dB
Max RF
Intercept Cur. mA
Coolant
L-4920 40 -80 -80 -107 -26 90.0 2000 25
L-4922 40 -80 -80 -107 -26 90.0 70 5
L-4923 40 -80 -80 -107 -26 90.0 2000 2
L-4950 40 -80 -80 -107 -26 90.0 500 2
L-4966 40 -80 -80 -107 -26 90.0 70 5
L-4995 40 -80 -80 -107 -26 90.0 300 10
Physical Description
Product # RF
Input Con.
RF
Output Conf.
Overall
Length inches
Body
Diameter inches
Weight
lbs
RF Output
Press. psia
Coolant
con.
L-4920 SC 3-1/8 Coax 140 12 350 15 Quick
Disconnect
L-4922 N WR650 76 10 240 20 Quick
Disconnect
L-4923 N WR650 -Half Height 68 9 110 15 Quick
Disconnect
L-4950 N WR284 55 10 120 20 Quick
Disconnect
L-4966 SC WR650 76 10 240 25 Quick
Disconnect
L-4995 SC WR975-Half Height 76 10 235 25 Quick
Disconnect

Design Notes:

  1. All tubes are control grid modulated and also incorporate a shadow grid to assist in the suppression of grid emission and grid intercept current.
  2. All L3 Electron Devices' TWTs are inherently capable of dual-stage collector depression should it be necessary to fulfill a particular system requirement.
  3. A mod anode connection is provided on all TWTs and may be utilized to accommodate system sensing circuits and also reduce the potential damage incurrred by cathode-to-anode high-voltage arcs. This protection is accomplished through the incorporation of an external anode-to-ground resistance of two kilohms.
  4. All cathode and collector voltages are referenced to ground.