What’s The Difference Between A 40 Channel And 80 Channel UHF?

The other day I was going through a list of things I needed for trip I have planned for later in the year, My CB radio was on there and I got thinking it might be time for an upgrade. As I started looking, I now see that 80 Channel UHF’s are all the rage, so I decided to do some research on the differences are between a 40 and 80 Channel UHF radio to see if its worth making the switch.

So, What is the difference between a 40 channel and an 80 channel UHF radio?

Firstly, the number of channels available are different, one has 40 channels and the other has 80 channels. The 40 channel uhf radio is a wide band radio, meaning it expects a signal of 25khz. While the 80 channel radio is a narrow band, which expects a 12.5khz signal. Both the 40 channel and 80 channel UHF radio utilizes 476.4250-477.4125MHz radio spectrum for short distance communications.

Wait a minute, you might want to know a little more information about the differences in channels, not to mention how the different bandwidths affect usage, keep reading to learn more.

When using a 80 channel uhf it can be possible to communicate to someone using a 40 channel using the first 40 channels, or vice versa. However, due to the difference in band widths, the person on the 80 channel can come through quiet and be difficult to hear to the person using the 40 channel.

While, an 80 channel communicating with a 40 channel, can have issues as the 40 channel can come through distorted or significantly louder, this is due to the difference in band widths. For the best signal between transmissions, it is ideal to have units that are utilizing the same bandwidth, either 40 channel communicating with 40 channel, or 80 channel communicating with 80 channel.

So Which One Is Better?

Although, the debate between which system is better to use, a 80 channel uhf radio has a better chance of less traffic. This means you can communicate to your particular group or who you wish to talk to, without too much interference from others. However, a 40 channel has been around longer, so it can be more common to find a 40 channel unit in older vehicles.

Both the 40 and 80 channel uhf can work anywhere, including places with little to no infrastructure to transmit the signal. However, this means they tend to work in a line of sight way as they have a short reach. Although, this is a positive because you are certain that you are communicating with those in your immediate vicinity.

Terrain can affect how well the signal is transmitted or received as well. Under normal conditions, you can expect a good signal between 5-8 km in distance. Distance can be increased up to 25km if you are situated in a high position, for example a hilltop. However, transmissions will perform quite poorly if the signal is blocked by hilly or heavily forested areas.

What is duplex mode?

UHF radios have a duplex function. This function is used to increase the range of which you can communicate. This is done by using repeater stations, set in ideal locations such as hills. There are 16 input stations and 16 output stations. The fixed position station forwards the signal it receives from the repeater input station (31-38/71-78) to the corresponding output station (1-8/41-48).

Transmissions sent on non-duplex channels are sent in simplex mode, which is directly between two radio sets without the use of a repeater.

What channels Should I use?

Whether you are using the 40 or 80 channel uhf radio, you need to know which channels you can use and what the purpose of each channel is for. The accepted use of the channels are as follows:

  • Channels 1-8 and 41-48: Duplex output channels
  • Channels 31-38 and 71-78: Duplex input channels
  • Channels 5 and 35: Duplex channels strictly used for emergency communications
  • Channels 9, 12-17, 19-21, 24-28, 30, 39, 49-60, 64-70, 79 and 80: General chat channels, simplex use
  • Channel 10: 4WD clubs or convoys and national parks
  • Channel 11: Call channel used to located friends (general meeting point for when communications are beginning or lost, before moving to another channel)
  • Channel 18: Caravanners and campers convoy channel
  • Channel 40: Australia wide road safety channel (used primarily by truckies and over sized load pilot vehicles)
  • Channels 22 and 23 (25kHz): Data communications only
  • Channel 29: Road safety channel Pacific Hwy, Pacific Mwy (NSW and OLD)
  • Channels 61-63: Reserved for future use

The maximum penalties for the misuse of the emergency channels are:

  • General misuse: 2 years imprisonment, otherwise $165,000 (a $220 on-the-spot fine can be issued for minor cases)
  • Interference to an emergency call: 5 years imprisonment, otherwise $550,000


What frequencies are the channels?

Below is a table that specifies the frequencies of each channel, as well as the purpose of that channel.











Channel 1476.4250Duplex – Repeater Output12.5 KHz
Channel 2476.4500Duplex – Repeater Output12.5 KHz
Channel 3476.4750Duplex – Repeater Output12.5 KHz
Channel 4476.5000Duplex – Repeater Output12.5 KHz
Channel 5476.5250Duplex – Repeater Output (Emergency use only)12.5 KHz
Channel 6476.5500Duplex -Repeater Output12.5 KHz
Channel 7476.5750Duplex -Repeater Output12.5 KHz
Channel 8476.6000Duplex -Repeater Output12.5 KHz
Channel 9476.6250Simplex12.5 KHz
Channel 10476.6500Simplex 4WD Drivers – Convoy, Clubs & National Parks12.5 KHz
Channel 11476.6750Simplex Call Channel12.5 KHz
Channel 12476.7000Simplex12.5 KHz
Channel 13476.7250Simplex12.5 KHz
Channel 14476.7500Simplex12.5 KHz
Channel 15476.7750Simplex12.5 KHz


Channel 16476.8000Simplex12.5 KHz
Channel 17476.8250Simplex12.5 KHz
Channel 18476.8500Simplex Caravan & Campers Convoy Channel12.5 KHz
Channel 19476.8750Simplex12.5 KHz
Channel 20476.9000Simplex12.5 KHz
Channel 21476.9250Simplex12.5 KHz
Channel 22476.9500Data Only (No Voice – No Packet)25 KHz
Channel 23476.9750Data Only (No Voice – No Packet)25 KHz
Channel 24477.0000Simplex12.5 KHz
Channel 25477.0250Simplex12.5 KHz
Channel 26477.0500Simplex12.5 KHz
Channel 27477.0750Simplex12.5 KHz
Channel 28477.1000Simplex12.5 KHz
Channel 29477.1250Simplex Pacific Hwy (NSW) & Bruce Hwy (QLD) Road Channel12.5 KHz
Channel 30477.1500Simplex UHF CB Broadcasts12.5 KHz
Channel 31477.1750Repeater Input12.5 KHz
Channel 32477.2000Repeater Input12.5 KHz
Channel 33477.2250Repeater Input12.5 KHz
Channel 34477.2500Repeater Input12.5 KHz
Channel 35477.2750Repeater Input (Emergency Use Only)12.5 KHz
Channel 36477.3000Repeater Input12.5 KHz
Channel 37477.3250Repeater Input12.5 KHz
Channel 38477.3500Repeater Input12.5 KHz
Channel 39477.3750Simplex12.5 KHz
Channel 40477.4000Simplex Highway Channel12.5 KHz
Channel 41476.4375Duplex -Repeater Output12.5 KHz
Channel 42476.4625Duplex -Repeater Output12.5 KHz
Channel 43476.4875Duplex -Repeater Output12.5 KHz
Channel 44476.5125Duplex -Repeater Output12.5 KHz
Channel 45476.5375Duplex -Repeater Output12.5 KHz
Channel 46476.5625Duplex -Repeater Output12.5 KHz
Channel 47476.5875Duplex -Repeater Output12.5 KHz
Channel 48476.6125Duplex -Repeater Output12.5 KHz
Channel 49476.6375Simplex12.5 KHz
Channel 50476.6625Simplex12.5 KHz


Channel 51476.6875Simplex12.5 KHz
Channel 52476.7125Simplex12.5 KHz
Channel 53476.7375Simplex12.5 KHz
Channel 54476.7625Simplex12.5 KHz
Channel 55476.7875Simplex12.5 KHz
Channel 56476.8125Simplex12.5 KHz
Channel 57476.8375Simplex12.5 KHz
Channel 58476.8625Simplex12.5 KHz
Channel 59476.8875Simplex12.5 KHz
Channel 60476.9125Simplex12.5 KHz
Channel 61Reserved for Future Expansion
Channel 62Reserved for Future Expansion
Channel 63Reserved for Future Expansion
Channel 64477.0125Simplex12.5 KHz
Channel 65477.0375Simplex12.5 KHz
Channel 66477.0625Simplex12.5 KHz
Channel 67477.0875Simplex12.5 KHz
Channel 68477.1125Simplex12.5 KHz
Channel 69477.1375Simplex12.5 KHz
Channel 70477.1625Simplex12.5 KHz
Channel 71477.1875Repeater Input12.5 KHz
Channel 72477.2125Repeater Input12.5 KHz
Channel 73477.2375Repeater Input12.5 KHz
Channel 74477.2625Repeater Input12.5 KHz
Channel 75477.2875Repeater Input12.5 KHz
Channel 76477.3125Repeater Input12.5 KHz
Channel 77477.3375Repeater Input12.5 KHz
Channel 78477.3625Repeater Input12.5 KHz
Channel 79477.3875Simplex12.5 KHz
Channel 80477.4125Simplex12.5 KHz



Most users are well behaved, however, you will encounter those who just want to troll and cause trouble, or new users who are unaware of the etiquette. It is important to remember that all communications on each channel are public. Anyone within range can hear you and join in. When communication has been established, it is accepted that both parties move to another channel to free up that particular channel ie. Emergency channel or the call channel.

Related Questions

What is the pricing difference between handheld and in car UHF radios?

Pricing can vary on the features and quality of the product. Handheld uhf radios are portable and range from as little as $40 to over $400, while in car uhf radios can range from $100 to over $600.

What to features to look for when choosing your UHF?

There are many 40 channel and 80 channel units that are available, each with various features that are available. Here are a couple features you should consider:

  • Programmable Scan function: scans up to 40 user programmable channels with both group and open scan functions available
  • Over-voltage protection: special over-voltage detection circuitry protects the radio andwarns of excessive voltage conditions by flashing the display
  • CTSS ready: built in continuous tone coded squelch system provides quiet channel operation

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