UHF or VHF: Which Radio Do You Actually Need?

The short version

For everyday convoy communication, a compliant UHF CB is a practical starting point. It operates under a class licence: you do not apply or pay a licence fee, but equipment, channel and operating rules still apply. ACMA: Citizen Band Radio Stations Class Licence 2025.

Frequency alone does not settle the choice

Range depends on the radio system, antenna, height, installation, terrain and available repeaters. A generic UHF-versus-VHF table cannot predict reliable communication on your route, and a VHF antenna is not inherently impractical on a vehicle.

Do not treat marine frequencies as general convoy channels. Licensed maritime coast stations can lawfully operate on land for their authorised purpose, so “all marine VHF use on land is illegal” is too broad. Other services have their own authorisations and operator requirements. ACMA: maritime coast licence options.

What actually determines your range

People buy a 5 watt radio expecting five times the range of a 1 watt one. It does not work like that. In rough order of what matters:

1. Terrain and path. Hills, buildings and vegetation can weaken or obstruct a signal. Test communication on the route and do not assume a published range will be available.

2. Antenna position. Use the antenna maker’s mounting instructions and check the complete vehicle installation; one generic bull-bar/bonnet/roof ranking cannot resolve every setup.

3. Antenna compatibility. Check matching, connections, cable routing and whether the design requires a ground plane. Do not assume all antennas have the same installation needs.

4. Gain and terrain. Compare the manufacturer’s radiation pattern and intended use. More quoted gain is not a guarantee of a stronger connection in every direction.

5. Power output. Last. Going from 1 to 5 watts is a worthwhile improvement, not a transformation.

Handheld, or fixed in the vehicle

A handheld is 1–5 watts with a short rubber antenna and no ground plane. Fine for talking between vehicles a few hundred metres apart, for spotting someone through an obstacle, and for camp. Buy one regardless.

A fixed unit with a proper external antenna is a different instrument. It is what you want for convoy work, for hearing road-train traffic on the highway, and for calling for help from a track. If you only fit one thing, fit this.

Channels worth knowing

ACMA reserves UHF channels 5/35 for emergency messages and 22/23 for permitted telemetry/telecommand, with no voice on 22/23. Repeater channel pairs also have conditions. In an emergency any CB frequency may be used to attract attention. Agree a suitable non-reserved convoy channel and follow the current class-licence rules; do not assume an emergency channel is monitored. ACMA channel and emergency rules.

The thing neither band does

UHF and VHF are both line-of-sight. Alone on a track in remote country with a broken vehicle, a radio talks to whoever happens to be within a few kilometres and in sight of you. If nobody is, it does nothing.

That is not an argument against a UHF — it is the most useful everyday communication tool in the vehicle. It is an argument that for genuinely remote travel a satellite messenger or satellite phone is the actual safety device, and the radio is for convenience and convoy coordination. They solve different problems. The overlanding guide covers where that line sits.

What we'd fit

Our starting preference is a properly installed UHF CB for convoy use and a handheld where spotting or camp communication warrants it. Remote travel needs a separate emergency communication plan, such as an appropriate PLB or satellite service, with its registration, coverage and subscription requirements checked. No radio package guarantees help will be within range.