User Manual Part 2

Lynx.GX Installation and Management

PLANNING FOR AND SELECTING IF CABLE

The radio can be installed with the RFU mounted indoors above the IDU in a 19-inch (or 23-inch) rack, or

mounted outdoors onto the pole-mounted bracket (sold separately).

For indoor mounting, a short IF coaxial cable is included in the IDU accessory kit to connect the IDU to the RFU;

the cable is TNC (male) to TNC (male), about 12 inches in length. A low-loss RF transmission line is required to

run the RF signal from the RFU to the antenna (located outdoors atop a tower, monopole, rooftop pole, or cell

site. The choices for RF transmission line are discussed in the next section.

For outdoor RFU mounting, a long IF coaxial cable is required to connect the IDU to the RFU outdoors. The

recommended cables are listed in the following table. The IF cable shall not exceed 1000 feet (300 meters).

Select UV-resistant sheathing on the cable.

IF Transmission Line

Type

-inch coaxial

Manufacturer

Times Microwave Times Microwave

Model

LMR-240 LMR-400

Connectors (needed to connect to RFU and IDU)

TC-240-TM “TNC” TC-400-TM “TNC”

Loss* per 100 ft. at 748 MHz IF (up stream)

7.6 dB 3.9 dB

Loss* per 100 ft. at 140 MHz IF (down stream)

3.0 dB 1.5 dB

DC Resistance* per 100 ft. (center conductor

plus shield)

0.709 ohms 0.304 ohms

Recommendation for length of cable For cable lengths less than

330 ft or 100 meters

For cable lengths up to 1000

ft. or 300 meters

Radio maximum IF loss: <35 dB at 748 MHz (upstream), <15 dB at 140 MHz (downstream)

Radio maximum DC resistance (center plus shield): < 3.5 ohms

*Source: Times Microwave Systems Communications Coax Selection Guide

Equivalent or lower-loss cable can be used in place of the two cables listed in this table. Be sure to use cable

rated for outdoor use (UV-resistant sheathing).

Note: Always apply waterproof butyl tape after the cable has been installed onto the RFU outdoors.

The connectors on both ends should be TNC (male) to TNC (male). Multiple cables can be used to

accomplish IDU-to-egress and egress-to-RFU connections, including lightning protection devices. All device

losses and resistances (including connectors) must be added and maintained within the limits listed above.

Appendix A. Installation Planning 53