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™ OFR400 RF MODULES
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USER MANUAL
DCM000000019
Printed: 00.04.11,13:13
Revision Date:4/11/00
4
Theory Of Operation
An OFR, or On Frequency Repeater, is a radio repeater that simultaneously
receives and transmits a single narrow band radio channel on exactly the same
frequency.
The OFR accomplishes its repeater function without store and forward circuitry, or
expensive conventional simulcasting techniques. The fact that the same frequency
is retransmitted by an OFR means that additional frequency allocations are not
required in situations where an existing radio coverage pattern needs to be
extended. The most common OFR applications are the extension of above ground
signals into buildings, tunnels, vehicles or the extension of radio coverage patterns
into outdoor shaded areas such as deep valleys.
From an applications standpoint, an OFR is very similar to a regular two-way radio
repeater. On Frequency Radio Repeaters can be combined using regular two-way
radio multicoupling or duplexing equipment and have input and output signal
characteristics to those of regular transmitters and receivers. The one special
consideration in OFR systems is that of input to output antenna isolation. This must
be carefully engineered for each installation.
Standard On Frequency Radio Repeaters are designed for indoor use only and are
intended for mounting in a standard EIA 19 inch rack. Modular design of OFR
circuitry allows for easy servicing, stocking of spares, adaptability and upgrade
ability.
OFR400 MODULE FAMILY
MODEL
TYPE
FREQUENCY
OFR400-A1
25 KHz Channels
403-430 MHz (FM)
OFR400-A2
12.5 KHz Channels
403-430 MHz (FM)
OFR400-B1
25 KHz Channels
430-450 MHz (FM)
OFR400-B2
12.5 KHz Channels
430-450 MHz (FM)
OFR400-C1
25 KHz Channels
440-470 MHz (FM)
OFR400-C2
12.5 KHz Channels
440-470 MHz (FM)
OFR400-D1
25 KHz Channels
470-490 MHz (FM)
OFR400-D2
12.5 KHz Channels
470-490 MHz (FM)
OFR400-E1
25 KHz Channels
490-512 MHz (FM)
OFR400-E2
12.5 KHz Channels
490-512 MHz (FM)
1 . O F R 4 0 0 M O D U L E S
Overview
Models
