GENERAL DESCRIPTION
NEC LD7217 series of PPM-focused traveling wave tubes are designed for use as final amplifiers in the earth-tosatellite communications transmitter.
LD7217S and LD7217 are capable of delivering an output power of 600 W and 700 W over the range of 5.85 to 6.425 GHz and provide a high gain of 45 / 54 dB at 600 / 700 W level . In addition, LD7217W is capable of delivering an output power of 700 W with a gain of 54 dB over the range of 5.85 to 6.65 GHz. The LD7217 series provide a flat gain variation of 1.5dB (LD7217S) ,1.0dB (LD7217) and 1.8dB (LD7217W) at any power level.
Furthermore, these are of rugged and reliable design offering long-life service.
LD7217S is fully compatible with VTC6361B3, and LD7217 is also fully compatible with VTC6361B4.

FEATURES
○ High Power Gain
    The power gain is typically 45 dB at 600 W level and 54 dB at 700 W level.
○ Simple Cooling System
    All the tubes are forced-air-cooled, so that the cooling systems are greatly simplified.
○ PPM Focusing
    The tubes are PPM (Periodic Permanent Magnet) -focused, eliminating entirely the focusing power supplies and
    interlock circuits.
○ Rugged Construction
    The tubes are designed to be rugged, therefore they are suitable for transportable systems.
○ Long Life and High Stability
    The tubes employ an advanced impregnated cathode with a low operating temperature for long life.
○ Microdischarge Free
    The tubes are carefully designed to be free from microdischarge in the electron gun for long term operation, therefore they are suitable for digital communication service.