UHF CB radio in Australia runs on shared channels between 476.4125 and 477.4125 MHz under an ACMA class licence, which means no licence application and no fees for anyone using a CB radio. A handful of channels have fixed jobs: channels 5 and 35 are set aside for emergency messages, channel 11 is the calling channel, channels 22 and 23 carry telemetry only with no voice allowed, and channels 1 to 8 and 41 to 48 pair with 31 to 38 and 71 to 78 for repeater use. Everything else is open voice. This guide explains each channel group, how repeaters work, and which radio and antenna suit a work crew.
In this article
- Do you need a licence for UHF CB in Australia?
- What is each UHF channel used for?
- How do repeater channels work?
- Which UHF radio suits a work crew?
- Does the antenna matter as much as the radio?
- Frequently asked questions
Do you need a licence for UHF CB in Australia?
No. UHF CB operates under the ACMA Citizen Band Radio Stations Class Licence, a standing licence that covers everyone. There is nothing to apply for and no fee to pay, but the class licence rules still apply to every user: equipment cannot exceed the stated maximum power, only designated channels may be used, and the service carries voice plus telemetry and telecommand only, no packet radio or other data. Call signs are not required, though ACMA recommends identifying yourself on air.
What is each UHF channel used for?
The channels split into groups with fixed jobs under the class licence, plus a few conventions Australian road users follow by habit rather than law:
| Channel | Use | Status |
|---|---|---|
| 5 and 35 | Emergency messages only. Do not chat here | Class licence rule |
| 11 | Calling channel. Make contact, then move to another channel | Class licence rule |
| 22 and 23 | Telemetry and telecommand only. No voice permitted | Class licence rule |
| 1 to 8, 41 to 48 | Repeater output channels | Class licence rule |
| 31 to 38, 71 to 78 | Matching repeater input channels. Avoid simplex use where a repeater may be in range | Class licence rule |
| 40 | The road channel: trucks, highway traffic and road safety talk | Convention |
| 18 | Caravanners and campers | Convention |
| 10 | 4WD clubs and convoys | Convention |
| The rest | General voice channels, shared with all users | Open |
Two notes worth pinning. In a genuine emergency, ACMA allows any CB frequency to be used to attract attention, the 5/35 reservation is about keeping those channels clear, not stopping you calling for help wherever you can be heard. And a work crew talking all day should pick a quiet general channel, not squat on the calling channel or a convention channel that other road users rely on.
How do repeater channels work?
A repeater is a fixed station, licensed separately under an apparatus licence, that receives on one channel and re-transmits on another from a high point, stretching UHF coverage across terrain that blocks direct radio-to-radio contact. The pairing is fixed: a repeater transmitting on channel 1 always receives on channel 31, and so on through the output channels 1 to 8 and 41 to 48 and their inputs 31 to 38 and 71 to 78. Put your radio in duplex or repeater mode and it selects the matching frequency automatically.
Where no repeater operates nearby, the class licence allows those channels for ordinary single-frequency use, with a warning attached: simplex traffic on repeater channels can interfere with a repeater a long way away, so they are a poor choice for routine crew chatter.
Which UHF radio suits a work crew?
The split is handheld versus in-vehicle. Handhelds move with the worker: a traffic controller at a stop point, a spotter behind a reversing truck, a crew spread along a work area. For that duty an IP67 rating matters as much as power, the radio lives outdoors in weather and gets dropped. In-vehicle mobiles wire into the work truck with an external antenna, which buys steadier performance on the road channel and nothing to leave on a charger.
5 watt IP67 handheld with the full accessory kit. The standard-issue handheld for traffic crews and site work.
Two 5 watt IP67 handhelds in one pack, the straightforward buy for crew pairs working a stop point each.
Super compact 5 watt in-cab UHF CB value pack for a fixed vehicle install with an external antenna.
UAGS also stocks the MGX H5 5W handheld with speaker mic as an 80-channel alternative, and the TX6165X as the radio-only version of the workhorse above.
Does the antenna matter as much as the radio?
On a vehicle install, yes. The radio sets the transmit power, but the antenna and where it mounts shape how far the signal usefully carries, and a poorly mounted antenna wastes a good radio. UAGS carries the GME AE4002 150mm 2.1dBi whip for compact installs, along with bullbar mounting brackets, antenna springs and vehicle-specific bonnet mounts for Hilux and Triton.
Compact 2.1dBi flexible whip for utes and plant where clearance matters.
Frequently asked questions
Do I need a licence to use a UHF CB radio in Australia?
No. UHF CB operates under the ACMA Citizen Band Radio Stations Class Licence, which covers all users automatically with no application and no fees. The class licence rules still apply, including power limits and channel restrictions.
What UHF channel do trucks use?
Channel 40 is the general road channel used by trucks and highway traffic. It is a convention rather than a class licence rule, but it is followed Australia-wide, so treat it as the place for road safety talk, not crew chatter.
Which UHF channels are for emergencies?
Channels 5 and 35 are set aside for emergency messages only. In a genuine emergency, though, ACMA allows any CB frequency to be used to attract attention.
Can I talk on channels 22 and 23?
No. Channels 22 and 23 are reserved for telemetry and telecommand, and voice is not permitted on them. Packet radio and other data are not allowed anywhere else on the CB bands.
What is CTCSS on a UHF radio?
Continuous Tone Coded Squelch System, the selective calling method permitted on UHF CB. It filters what your radio plays out loud so you only hear calls carrying your group's tone, but the channel itself is still shared: anyone listening without CTCSS hears everything.
What range does a UHF radio get?
There is no single number. UHF is effectively line of sight, so range depends on terrain, antenna quality and mounting height, and transmit power. Flat open country carries much further than hilly or built-up ground, and a repeater extends coverage well beyond direct radio-to-radio range.
Kit your crew with UHF that survives the job
GME handhelds, twin packs, in-vehicle units, antennas and mounts. Trade pricing available. Pickup from Bayswater North VIC or delivery Australia-wide.
Browse UHF CB Radios →Channel arrangements and operating rules are set by the ACMA class licence and may change; check current ACMA guidance for anything critical. This article is general information for the Australian market.