NEC LD7217, LD7217W, LD7217S Datasheet

DATA SHEET

HIGH POWER TRAVELING WAVE TUBE

FOR GROUND TERMINALS

LD7217 SERIES

6 GHz, 600 W/700 W CW, PPM FOCUSING,

HIGH POWER GAIN

GENERAL DESCRIPTION

NEC LD7217 series of PPM-focused traveling wave tubes are designed for use as final amplifiers in the earth-to-

satellite 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.

For safe use of microwave tubes, refer to NEC document “Safety instructions to all personnel
handling electron tubes” (ET0048EJ∗V∗UM00)

The information in this document is subject to change without notice.

Document No. ET0190EJ3V1DS00 (3rd edition)
Date Published August 1998 M
Printed in Japan

©

1996

GENERAL CHARACTERISTICS

ELECTRICAL

Frequency

LD7217, LD7217S ……………………………… 5.85 to 6.425 GHz
LD7217W ………………………………………… 5.85 to 6.65 GHz

Output Power

LD7217S ………………………………………… 600 W

LD7217, LD7217W ……………………………… 700 W
Heater Voltage……………………………………… 6.3 V
Heater Current ……………………………………… 1.7 A
Type of Cathode …………………………………… Indirectly heated, Impregnated
Cathode Warm-up Time ………………………… 180 s

MECHANICAL

Dimensions ………………………………………… See Outline
Weight ……………………………………………… 7 kg approx.
Focusing …………………………………………… Periodic Permanent Magnet
Mounting Position ………………………………… Any
Electrical Connections …………………………… AMP LGH-1I
Thermal Switch Connection …………………… Deutsch DM9601-3P
RF Connections

Input ……………………………………………… N-Female

Output …………………………………………… Mates with CPR-137F Flange
Cooling ……………………………………………… Forced Air

LD7217 SERIES

ABSOLUTE RATINGS (Note 1, 2 and 3)

ELECTRICAL

Heater Voltage………………………………………… 6.0 6.6 V
Heater Surge Current ……………………………… – 5.0 A
Heater Current ………………………………………… 1.5 2.5 A
Heater Warm-up Time ……………………………… 180 – s
Helix Voltage …………………………………………10.2 11.9 kV
Helix Current ………………………………………… – 25 mA
Accelerating Anode Voltage ……………………… 0 Note 5 kV
Accelerating Anode Current ……………………… – 2.0 mA
Collector Voltage ……………………………………… 5.7 7.5 kV
Cathode Current ……………………………………… – 475 mA
Drive Power …………………………………………… – 0.1 W
Load VSWR …………………………………………… – 1.7:1

MECHANICAL

Cooling Air Flow ……………………………………… 204 – kg/hr
Ambient Temperature

Storage ……………………………………………… –30 +70 ˚C

Operation …………………………………………… –10 +60 ˚C

Min. Max. Unit

Min. Max. Unit

2