UHF radio channels explained: what to actually use them for

Somewhere out past Yunta on the way to Broken Hill a few years back, I sat behind a road train for the better part of twenty minutes because I hadn't switched off channel 18 and onto channel 40 like every other sensible traveller on that stretch. The truckie finally came through loud and clear, not terribly impressed, wanting to know why the grey nomad in the white Colorado hadn't heard him calling for the last ten kilometres. Fair call. I'd been yarning to Denise on our convoy channel and completely missed him. Lesson learned, and one I've never repeated.

UHF radio is one of those bits of kit that everyone buys and almost nobody uses properly. You see it mounted under the dash of every second rig at a servo from Ceduna to Charters Towers, aerial whipping around, and half the owners couldn't tell you the difference between channel 40 and channel 18 if you asked them straight. So let's sort that out, because knowing your channels is the difference between a relaxed lap and a very long, very awkward wait behind a triple road train.

Why UHF and not just your mobile

The obvious answer is coverage. Mobile reception drops out the minute you're twenty minutes past most regional towns, and a UHF set works line-of-sight regardless of whether Telstra or anyone else has bothered running a tower out that way. We use ours daily, and not just in the never-never — even pottering around the Bright Holiday Park in the high country, Denise and I keep a set in the van and one handheld for whoever's out walking the dog, because mobile signal in a valley like that can be patchy at best.

A UHF radio, for anyone who hasn't looked into it, is a two-way transceiver that operates on the 476-477 MHz band under Australian Communications and Media Authority rules. No licence required for the standard Citizen Band channels, forty watts max for vehicle-mounted units, five watts for handhelds. Range depends entirely on terrain and aerial height — flat outback country you might get fifteen to twenty kilometres reliably, hilly or timbered country you'll be lucky to get three or four. That's the bit people don't grasp when they're disappointed their new set "doesn't work properly." It's working exactly as it should. Line of sight is the whole game.

The channels that actually matter

There are 80 channels available, and you genuinely only need to know a handful of them well. Channel 5 and 35 are the emergency channels, monitored in many areas though don't rely on it as your sole emergency plan — that's what a satellite messenger or PLB is for out bush, and Bec's written plenty on that side of things. Channel 9 was the old emergency channel and is now general use, though some habits die hard and you'll still hear it used that way in older convoys.

Channel 18 is the caravanner and camping convoy channel. This is where you'll hear grey nomads coordinating a run up the Birdsville Track or a group heading into the Oodnadatta Track together, calling out potholes, cattle on the road, or just organising where to pull up for smoko. It's become the unofficial home of the touring community and for good reason — it's set aside for exactly this use.

Channel 40 is the highway and truckie channel, and this is the one that matters most for your own safety. Truck drivers use it constantly to call out their position on single-lane bridges, blind corners, and when they're about to overtake or be overtaken. If you're towing on any highway with regular heavy vehicle traffic — the Newell, the Bruce, the Stuart — channel 40 should be on, always, not just when you remember. I'd argue it's more important than your convoy channel most of the time, and that's a slightly unpopular view among nomads who like a good chinwag on 18 all day.

Channel 29 is often used as a secondary highway channel in some states, and channel 10 has become common for four-wheel drive club convoys, though this varies by region and club, so ask before you assume. Repeater channels sit in the range from about channel 1 to 8 and 31 to 38 in some configurations — these bounce your signal off a fixed repeater station on a hill or tower to extend range considerably, useful in mountainous country like the high country runs around Wonnangatta where line-of-sight direct transmission is hopeless.

Setting up your radio properly

Half the complaints I hear about UHF range come down to aerial mounting, not the radio itself. A radio mounted low with a short stubby aerial will always underperform one with a proper 6.5dBi or similar gain aerial mounted high on the van or a bullbar. We run a fibreglass aerial on the roof of the tow vehicle rather than the van itself, mostly because vehicle-mounted keeps line of sight forward and back, whereas van-mounted can get partially shadowed by the vehicle in front of it depending on your setup.

Scan function is worth understanding too. Most decent sets these days will scan across channels and lock onto activity, which is handy if you're not sure what channel a convoy or a local club is using. CTCSS and DCS codes — sometimes called "squelch codes" — let you filter out chatter from other users on the same channel, useful in busy areas near cities but honestly more trouble than they're worth out in genuinely remote country where you want to hear everything, including the road train that's about to come round the bend.

Etiquette that keeps everyone sane

There's an unwritten code out there, and it's not complicated. Keep transmissions short. Identify yourself and your direction if you're calling out a hazard — "grey Colorado and van, heading south, road train about to pass" tells the other bloke everything he needs in five seconds. Don't sit on a working channel having a long conversation about your daughter's wedding when you're supposed to be monitoring for trucks. And if someone calls out a hazard, acknowledge it, even just a "copy that," so they know you've heard.

We picked up most of this etiquette the hard way, listening and occasionally getting gently corrected by truckies who've heard every excuse in the book. It's a small community out there on the airwaves and word travels — behave badly on channel 40 near Port Augusta and don't be surprised if someone mentions it three hundred kilometres later.

What to actually buy

You don't need the most expensive set on the shelf. A mid-range 5-watt handheld from GME or Uniden will do everything most grey nomads need for around $150 to $250, and a vehicle-mounted 40-watt unit with a separate speaker and a decent aerial will run you somewhere in the $300 to $500 bracket depending on features. Repeater capability is worth having if you're doing serious remote touring — places like the Gunbarrel Highway or the Anne Beadell Highway where you might genuinely need every bit of range you can get, though frankly in that sort of country a satellite communicator matters more than which UHF channel you're on.

One thing I will say, and it's a slightly contrarian view among some of the tech-heads in caravan forums: you don't need Bluetooth, GPS tracking, or app integration on your UHF set. It's a two-way radio. Keep it simple, keep the aerial good, and spend the money you save on a proper battery setup or better tyres instead.

Where it all comes together

The best test of whether you actually understand your UHF setup is a proper convoy run somewhere remote. We did the run into the Birdsville Track a few seasons back with another couple we'd met at the Wilpena Pound campground, and having channel 18 sorted between us meant we never lost each other across two hundred kilometres of dust and corrugations, calling out bulldust holes and stock on the track well before either rig hit them. That's the whole point of the exercise. Not a toy, not a gimmick — just a tool that does exactly one job, and does it properly if you've bothered to learn it.

Get the channels sorted before you leave the driveway, not somewhere out past Yunta with a road train bearing down and Denise wondering why I've gone quiet on the radio again.

— Trev Sanders, Grey Nomad Correspondent