Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

170 marine electronics installation and troubleshooting

Minimum Bend

Cable Type Radius (inches)

RG-58/U 2.0

RG-8X 2.4

RG-8/U 4.5

RG-213 5.0

LMR-240 0.75

LMR-400 1.0

Source:NMEA

Minimum Bend Radii of

Coaxial Cable, by Type

TABLE

16-5

Coax Connectors

In any circuit, the weakest link is generally at a

termination point, and it’s no different for

coaxial cable. The specialized end connectors

used to install coax reflect the fact that it is

really a multiconductor cable and is designed

to deliver signals of varying frequencies. Our

friends at the NMEA provide some guidance

here as well. The maximum operating fre-

quency and impedance for the various connec-

tor types available are shown in Table 16-6.

Connector Maximum Operating

Designator Frequency Impedance (ohms)

UHF (PL-259) 300 MHz 50

BNC 4.0 GHz 50

TNC 2.5 GHz 50

N 11.0 GHz 50

F 2.0 GHz 75

Mini UHF 2.5 GHz 50

SMA 12.0 GHz 50

SMB 4.0 GHz 50

FME 200 MHz 50

Source:NMEA

Coaxial Connector Selection

TABLE

16-6

PL-258

UHF double-female

M359

UHF 90 male/female

UHF double-male

M-348

UHF T-adapter

UHF female/

BNC male

UHF male/

BNC female

A few coaxial adapters. (Reprinted with permission from

Boatowner’s Illustrated Electrical Handbook,second edition,

by Charlie Wing)