(Ultra High Frequency)
Q. How do I upgrade my Compatible GME UHF
CB Radio to 80 Channels*
A. 80 Channel Upgrade Instructions- 31st May, 2011
The ACMA (Australian Communications and Media Authority) have
recently released a new class
licence allowing UHF CB radios to operate on a new 80 channel
narrow band standard.
In December 2010, in preparation for this new standard, GME began
building UHF CB radios that complied with both the original 40
channel wideband standard and the new 80 channel narrowband
standard. This allowed customers to purchase ‘future proofed’
40 channel radios prior to the release
of the new standard that could be switched to the new 80 channel
standard once it was mandated.
As of June, 2011, owners of compatible radios can now operate
on the new 80 channel narrow band
GME radios that are 80-channel compatible can be easily identified
by an ’80 Channel Upgradeable
sticker on the packaging and by the following serial number prefixes
Are there any special channels I should know about?
A. For 477Mhz UHF: channel 5 is your emergency channel,
channels 1-8 are your repeater stations (refer below to Simplex
and Duplex), channels 21 and 22 are data channels and may not
be used for sending or receiving transmissions (new model radios
block out these channels) and channel 40 is your highway channel
used by most trucks. For 27Mhz CB: channel 9 is your emergency
channel and channel 11 is your call channel.
What is VOX?
A. VOX stands for Voice Activated Transmissions and allows
the operator to have hands-free conversations. The microphone automatically
detects your voice or other nearby sound causing the radio to transmit
without the need press the PTT (push to talk) button.
What role does Squelch play on a radio?
A. Squelch allows the operator to eliminate / close off
background noise when there are no signals present. Strong incoming
signals override this closed squelch to be heard in the speaker.
Opening squelch allows background noise to be heard as well as allowing
weaker signals to be received. Weaker signals may come through as
a broken or chopped transmission by the squelch action.
What are the group scan and open scan functions?
A. Open scanning allows the operator to pickup transmissions
broadcasted on any of the 40 UHF channels. Group scanning allows
the operator to pickup transmissions broadcasted on any of the programmed
channels in the radio. Group scan channels may be user or dealer
programmable depending on the type of unit and may include any frequency
from the UHF band.
What is selcall?
A. Selcall stands for Selective Calling System. This feature
allows the operator to contact an individual or group of radios
using coded transmissions known as ANI (auto number ID) to notify
the corresponding radio of an incoming call.
What is CTCSS?
stands for Continuous Tone Coded Squelch System which provides quiet
channel operation by blocking unwanted signals being received except
those transmitting on your particular code. There are 38 codes per
channel to choose from.
What are Simplex and Duplex?
A. Simplex transmissions receive and transmit on the same
channel as far as the operator’s setup will allow. Duplex
transmissions utilise repeater stations around the country to onforward
signals giving a greater transmission / receive range. Duplex channels
are from 1 to 8 and transmit on one channel and receive on another.
Eg: If the radio is set to channel 3, it will receive on channel
3 but transmits thirty channels higher on channel 33 through the
repeater stations. All UHF radios have the ability to transmit using
Simplex or Duplex.