Crystal DBH034PK, User Manual, Page: 12 / 18

FUNCTION- USING THE UHF RADIO
Transmit & receive procedure
Your UHF radio contains a transmitter and receiver. To control your exposure and ensure
compliance with the general population/uncontrolled environment exposure limits, always
adhere to the following procedure:
Transmit no more than 50% of the time.
To receive calls, release the
“(PTT) button” on the microphone handpiece.
To transmit (talk), press the “(PTT) button” on the microphone handpiece.
When powered on and not transmitting, the radio is always in receive mode. When a
signal is received an RX full antenna symbol will display on the screen, when transmitting
TX display on the LCD.
For others to receive your transmission, they must be on the same channel as you and if
CTCSS or DCS is enabled, the same sub channel must also be selected.
NOTE: Before transmitting on a UHF channel, always listen to ensure it is not already in
use.
NOTE: Transmitting 50% of the time, or less, is important because the radio generates
measurable RF energy exposure only when transmitting (in terms of measuring standards
compliance).
NOTE: Do not transmit between two radios that are less than 1.5m apart, otherwise you
may experience interference.
NOTE: The UHF radio is simplex “one way at a time”. While you are speaking, you cannot
receive a transmission.
NOTE: The UHF radio is an open licence band. Always identify yourself when transmitting.
TRANSMITTING RANGE
The transmitting range will depend on the antenna, terrain, surroundings and environment,
it will be affected by obstructions such as hills, buildings and foliage. The use of duplex
mode will extend the transmission range in areas where a repeater station is present.
Channel 5 and 35 (paired for Duplex repeaters) are reserved as emergency channels and
should be used only in an emergency.
CTCSS will not operate on channels 5 and 35.
A list of currently authorised channels can be obtained from the ACMA website in Australia
and the MED website in New Zealand. Channel 11 is a calling channel generally used to
call others and channel 40 is the customary road vehicle channel.
Once contact is established on the calling channel, both stations should move to another
unused “SIMPLEX” channel to allow others to use the calling channel.
Channels 22 and 23
are for Telemetry and Telecommand use, voice communications are not allowed on these
channels by law. Channel 9 and above are the best choices for general use in Simplex
mode.