User's Manual

7
7.0 DC Power Injector Operation
A DC Power Injector is an in-line device that “injects” the DC power necessary to operate the
amplifier onto a transmission line. This allows the coax cable to carry both RF signals and DC
power to the mast-mounted amplifier. This precludes the need to run a separate power cable to
the remote mounted amplifier.
When grounded to a good earth ground through either the grounding stud or mounting flange,
the DC Injector will provide maximum lightning protection to your radio modem, wireless LAN
card or Access Point.
8.0 DC Power Injector Connections and Indicators
Red Transmit LED:
This LED glows RED when the amplifier goes into transmit amplification
mode. The Remote Transmit LED is controlled by unique circuitry, which
actually detects changes in the DC current traveling through the
transmission line to the amplifier. When the LED flashes, you know that
the remote pole amplifier is going into transmit mode.
Green Receive LED:
This LED glows GREEN when DC power is applied to the amplifier and it
goes into receive mode. When toggling between transmit and receive,
the LED will glow slightly dimmer.
“To Radio”
Connection:
This N-type female connects to the radio via a short jumper cable.
“To Amplifier”
Connection:
This N-type female connects to the amplifier on the mast using the coax
transmission line.
12 VDC:
This is the DC power input for the injector and is a standard 2.1 mm barrel
jack. +12VDC, center pin positive.
AUX 12VDC:
(Optional)
This jack parallels the 12 VDC power jack. It can be used to provide 12
VDC to the radio modem or Access Point using a short DC jumper cable.
The standard DC power supply that comes with the amplifier kit can be
used to power both it and the amplifier/DC Injector provided that the radio
device operates on 12 VDC and draws less then 600 ma. This extra jack
is installed when the DC-INJ-DUAL option is ordered.
9.0 Power Supply
The AMP2440 kit comes with a 100 to 240 VAC power supply that has a standard 2.1 mm
barrel plug [center pin positive (+) tip and outer ring negative (-)]. Although normally supplied
with a power supply, any 12 Volt DC, 1 amp (or greater) regulated power supply can be used.
The amplifier can operate from 11 to 14 VDC enabling battery or vehicle operation as well.
The DC power input is diode protected to prevent damage caused by reverse polarity input
voltages as well as by a TVS to protect it and the amplifier from over-voltage surges.