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3 base unit connectors, 4 test functions, 5 modulator (dual if) – Comtech EF Data CDM-750 User Manual

Page 36

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CDM-750 Advanced High-Speed Trunking Modem

Revision 2

Introduction

MN-CDM750

1–12

1.4.3

Base Unit Connectors

Alarm Connector

DB-15 male: Form C; Tx, Rx and unit faults; External Tx Carrier Off; IQ test point

Unit Management

• DB-9 male with EIA-232 and RS 485 2W/4W

• RJ-45 Ethernet (Maximum Ethernet packet size 1536 bytes including Ethernet header & CRC)

Tx & Rx IF Connectors

• 70/140 MHz: BNC

• L-Band: Type ‘N’ female

L-Band Monitor

Type ‘SMA’ female

Traffic Data Interface

• 2X RJ45 10/100/1000 BaseT Ethernet

• 1X Optical Gigabit Ethernet (optional)
Note: All Data Gig-E interfaces have a maximum Ethernet packet size of 1632 bytes including Ethernet
header & CRC

1.4.4

Test Functions

Data Test Pattern

2^10-1, 2^15-1 and 2^23-1 compatible with BERT on applicable interfaces

CW

Modulation disabled and CW signal is transmitted

SSB Carrier

Provides suppressed carrier and suppressed sideband

Loopback

Full Duplex only

1.4.5

Modulator (Dual IF)

70 / 140 MHz

Impedance / Connector

Output

Power

Power

Accuracy

50 to 180 MHz in 100 Hz steps, maximum symbol rate is within IF limits
75

Ω / BNC Female. Return Loss ≥ 18 dB

0 to -20 dBm, 0.1 dB steps (70/140 MHz)
±0.5 dB of nominal at 25

°C. Within ±0.5 dB from 25°C value at same frequency

L-Band

Impedance / Connector

Output

Power

Power

Accuracy

950-2150 MHz in 100 Hz steps, modulator maximum symbol rate is within IF limits
50Ω, Type N Female. Return Loss ≥ 15 dB
-5 to -40 dBm, 0.1 dB steps
±0.5 dB of nominal at 25

°C, ±0.5 dB from 25°C value at same frequency

L-Band Monitor

Port Impedance

Port Connector

Port Level

Port Isolation

Monitor Frequency


50

Ω (available in modulator only or modem configuration)

SMA Female
-27 dBm ± 3dBm
20 dB min
70/140 MHz: 900+70/140 MHz, L-Band: same.

Harmonics and Spurs

< 60 dBc/4kHz, modulated carrier. Excludes spectral mask area.

External Tx Carrier Off

TTL Low signal

Quadrature Phase Error and
Amplitude Imbalance

Sideband 35 dB below unmodulated carrier

Spectral Inversion

Normal or Inverted

Carrier Phase Noise

Frequency Offset

dBc/Hz

Frequency Offset

dBc/Hz

10 Hz

-36

10 kHz

-86

100 Hz

-66

100 kHz

-96

1 kHz

-76

1 MHz

-96

BUC 10 MHz Reference

Frequency Offset

dBc/Hz

Frequency Offset

dBc/Hz

10 Hz

-105

10 kHz

-148

100 Hz

-125

100 kHz

-150

1 kHz

-138