17
OPERATION
UNDERSTANDING REPEATERS
Operation through a repeater, where you transmit on one fre-
quency and receive on another, is called duplex operation. Oper-
ation direct to another station, where you transmit and receive on
the same frequency, is called simplex operation.
A repeater is a station that receives a signal on one frequency
(the input frequency) and then retransmits that signal on a differ-
ent frequency (the output frequency). Repeater antennas are typ-
ically located at the tops of tall buildings or on antenna towers, so
a relatively low-power signal can reach the repeater. The repeat-
er retransmits the signal at a higher power. This gives your trans-
ceiver the ability to communicate over a much greater range.
To use a repeater, you must know the repeater’s input and output
frequencies. Repeaters are usually identified by their output fre-
quency. Thus, a repeater that has an output frequency of 445.00
is referred to as the “445.00 repeater.” To determine the input fre-
quency, you must know the frequency offset (typically 600 kHz for
the 70cm band) and the offset direction (+ if you add 600 kHz
to the output, or – if you subtract 600 kHz from the output).
To determine the offset and the direction, obtain a copy of The
ARRL Repeater Handbook (available directly from the ARRL)
which lists the locations of repeaters as well as their frequency
and offset information.
RECEIVING, TRANSMITTING AND
SETTING SQUELCH
1. To turn on the radio, rotate
VOL/OFF
clockwise until it clicks.
The transceiver sounds a tone.
2. Rotate
SQ
counterclockwise until you hear a hissing sound.
Then slowly rotate
SQ
clockwise just until the noise stops.
3. Set
VOL/OFF
to a comfortable listening level.
19-1102.fm Page 17 Friday, March 19, 1999 4:08 PM
