NEC LD7215D, LD7215C, LD7215 Datasheet

DATA SHEET

HIGH POWER TRAVELING WAVE TUBE

FOR GROUND TERMINALS

LD7215, LD7215C, LD7215D

6 GHz, 3 kW, HELIX TYPE, PPM FOCUSING,

HIGH POWER GAIN, FLAT GAIN VARIATION

GENERAL DESCRIPTION

The NEC LD7215, LD7215C and LD7215D are PPM-focused traveling wave tubes designed for use as the final

amplifiers in the earth-to-satellite communications transmitter.

These are capable of delivering an output of 3 kW over the range of 5.85 to 6.425 GHz.
They provide a high power gain of 46 dB at an output power of 3 kW, and flat gain variation of 2.5 dB by LD7215,

1.0 dB by LD7215C and LD7215D at small signal level in the full frequency range.
Furthermore, they are of rugged and reliable design offering long-life service.
Both LD7215 and LD7215D are fully compatible with TH3640.

FEATURES

™ High Power Gain

The power gain is typically 52 dB at small signal level and 46 dB at 3 kW Ievel.

™ Simple Cooling System

All the tubes are forced-air-cooled, so that the cooling system is greatly simplified.

™ PPM Focusing

The tubes are PPM (Periodic Permanent Magnet) focused, and eliminate entirely the requirement for focusing
power supplies and interlock circuits.

™ Long Life and High Stability

The tubes employ 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 use in 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. ET0139EJ5V0DS00 (5th edition)
Date Published August 1998 M
Printed in Japan

©

1991

GENERAL CHARACTERISTICS

ELECTRICAL

Frequency ……………………………………………… 5.85 to 6.425 GHz
Cathode ………………………………………………… Indirectly heated, Impregnated

Heater Voltage …………………………………… 6.3 V
Heater Current …………………………………… 3.9 A

MECHANICAL

Dimensions …………………………………………… See Outline
Focusing ……………………………………………… Periodic Permanent Magnet
Electrical Connections ……………………………… Flying Leads (LD7215, LD7215D)

RF Connectors

Input ………………………………………………… Type SMA Female

Output ……………………………………………… Mates with CPR 137 Flange
Mounting Position ……………………………………Vertical (cathode down) or Horizontal
Weight ………………………………………………… 30 kg approx.
Cooling ………………………………………………… Forced Air

LD7215, LD7215C, LD7215D

AMP LGH 863023 Plug (LD7215C)

ABSOLUTE RATINGS (Note 1, 2, 3 and 4 )

ELECTRICAL

Heater Voltage……………………………………… 6.0 6.6 V
Heater Surge Current
Heater Current
HeaterWarm-up Time
Collector Voltage
Helix Voltage
Accelerating Anode Voltage
Collector Current
Helix Current
Accelerating Anode Current
Collector Dissipation
Helix Dissipation
Reflected Power
Load VSWR

MECHANICAL

Collector Temperature
Cooling Air Temperature (Inlet)

Cooling Air Flow

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Min. Max.

–8A
35A

300 – s

8.0 9.5 kV

12.5 13.7 kV

10.0 13.0 kV
– 1.5 A
–30mA

–0.5 1.0 mA

– 13.3 kW
–400W
–100W
– 1.5:1

–300°C

–20 45 °C
720 – kg/hr

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