UHF CB is a class-licensed citizen's band radio service authorised by the governments of Australia, New Zealand, Vanuatu, and Malaysia in the UHF 477 MHz band. UHF CB provides 77 channels, including 32 channels (16 output, 16 input) allocated to repeater stations. It is similar in concept to the 40 channels used in United States' HF CB allocation, which is also available in Australia and New Zealand.
Class Licensing means that users do not have to apply for a license or pay a license fee. All users are subject to the same license conditions. 
User equipment designs are similar to commercial land mobile two-way radio. Except for repeater stations and stations using the data-only channel, the maximum legal output power is 5 Watts. External antennas are permitted and common commercially manufactured antennas have gain as high as 12dB. Handheld transceivers (walkie talkies) are permitted and have transmit power from 500 mW to 5W (full legal power) and are relatively cheap compared to full-sized transceivers.
Other similar personal radio services used in other countries do not share the same band plan, power output, channels etc. as UHF CB. It is illegal to use these radios in Australia and New Zealand because they will interfere with other licensed land mobile services. Care must be taken with radios imported from overseas to ensure they comply with local regulations which is identified by an Australian standards C Tick usually found on the tag or sticker of the radio.
- 1 Selective calling (Selcall)
- 2 Continuous Tone Coded Squelch System (CTCSS)
- 3 Repeaters
- 4 Channel use
- 5 UHF CB band plan
- 6 New Zealand
- 7 See also
- 8 References
- 9 External links
Selective calling (Selcall)
Selective calling (Selcall) allows an individual radio to call another radio using a sequence of tones, usually presented to the user as a series of 5 numbers. UHF CB radios can be set to be completely silent until they receive a series of tones matching a pre-programmed sequence. Radios which have this feature usually indicate that a call has been received by emitting a number of beeps and by opening the squelch.
Continuous Tone Coded Squelch System (CTCSS)
Continuous Tone Coded Squelch System (CTCSS) allows a group of radios set with the same tone to converse on a channel without hearing other radios using that channel. CTCSS can be used to silence a radio until another radio with the same tone transmits. This allows monitoring of a channel for transmissions from radios set with the same tone without hearing other conversations that use different or even no tone.
The use of CTCSS is not permitted on UHF CB repeaters or the designated emergency channels.
Repeaters extend the range of transmission by receiving and automatically rebroadcasting a transmission using an antenna located in a high location, normally the top of a mountain, tall building or radio tower. Sometimes a transmission range of over 100 kilometres (60 miles) can be achieved through the use of a repeater. The repeater function on a UHF CB radio is normally referred to as 'duplex' or a 'range extender' function.
Whilst some channels are legally restricted in how they may be used (such as emergency channels), there is a consensus on how some of these channels are used depending on conversations or situations, but which are not officially recognised in the class licence.
Legally restricted channels
- Channel 5 and 35 are the designated emergency channels, and are not to be used except in an emergency. These channels are monitored by volunteers.
- Channel 11 is the 'call channel' and is only to be used for initiating calls with another person, who should quickly organise another vacant channel to continue their discussion on.
- Channel 22 and 23 are only to be used for telemetry and telecommand, packet data and voice transmission are not allowed.
- Channel 61, 62 and 63 are reserved for future allocation and transmission on these channels is not allowed.
Channels used by consensus
- Channel 10 is typically used for 4WD convoy, clubs and national parks.
- Channel 18 is the campers and caravan convoy channel, typically used by travelers.
Users should be aware that UHF CB channels 31 to 38 and 71 to 78 are the 'input' channels for repeaters on channels 1 to 8 and 41 to 48, and should avoid using these channels in simplex mode where they are in range of a repeater, to avoid interfering with it.
UHF CB band plan
Expansion to 80 channels
On 27 May 2011 the channel spacing on UHF CB was changed, allowing the band to expand from 40 channels to 80 channels. Due to data channels 22 and 23 occupying 25 kHz bandwidth, the expansion effectively allows the use of 77 channels, as channels 61, 62 and 63 are reserved.
Current UHF CB band plan (80 Channels)
General chat channels are used in simplex mode, whereas repeater channels must be used in duplex mode where a repeater on the same channel is nearby (to prevent interference). A repeater channel may only be used in simplex mode when there is no repeater nearby on the same channel.
|Channel Name:||Frequency:||Purpose:||Frequency Spacing:|
|Channel 1||476.4250||Repeater Channel||12.5 kHz|
|Channel 2||476.4500||Repeater Channel||12.5 kHz|
|Channel 3||476.4750||Repeater Channel||12.5 kHz|
|Channel 4||476.5000||Repeater Channel||12.5 kHz|
|Channel 5||476.5250||Emergency repeater output||12.5 kHz|
|Channel 6||476.5500||Repeater Channel||12.5 kHz|
|Channel 7||476.5750||Repeater Channel||12.5 kHz|
|Channel 8||476.6000||Repeater Channel||12.5 kHz|
|Channel 9||476.6250||General Chat Channel||12.5 kHz|
|Channel 10||476.6500||General Chat Channel||12.5 kHz|
|Channel 11||476.6750||Call Channel||12.5 kHz|
|Channel 12||476.7000||General Chat Channel||12.5 kHz|
|Channel 13||476.7250||General Chat Channel||12.5 kHz|
|Channel 14||476.7500||General Chat Channel||12.5 kHz|
|Channel 15||476.7750||General Chat Channel||12.5 kHz|
|Channel 16||476.8000||General Chat Channel||12.5 kHz|
|Channel 17||476.8250||General Chat Channel||12.5 kHz|
|Channel 18||476.8500||General Chat Channel||12.5 kHz|
|Channel 19||476.8750||General Chat Channel||12.5 kHz|
|Channel 20||476.9000||General Chat Channel||12.5 kHz|
|Channel 21||476.9250||General Chat Channel||12.5 kHz|
|Channel 22||476.9500||Telemetry & Telecommand Only (No Voice - No Packet)||25 kHz|
|Channel 23||476.9750||Telemetry & Telecommand Only (No Voice - No Packet)||25 kHz|
|Channel 24||477.0000||General Chat Channel||12.5 kHz|
|Channel 25||477.0250||General Chat Channel||12.5 kHz|
|Channel 26||477.0500||General Chat Channel||12.5 kHz|
|Channel 27||477.0750||General Chat Channel||12.5 kHz|
|Channel 28||477.1000||General Chat Channel||12.5 kHz|
|Channel 29||477.1250||12.5 kHz|
|Channel 30||477.1500||General Chat Channel||12.5 kHz|
|Channel 31||477.1750||Repeater Input||12.5 kHz|
|Channel 32||477.2000||Repeater Input||12.5 kHz|
|Channel 33||477.2250||Repeater Input||12.5 kHz|
|Channel 34||477.2500||Repeater Input||12.5 kHz|
|Channel 35||477.2750||Emergency repeater input||12.5 kHz|
|Channel 36||477.3000||Repeater Input||12.5 kHz|
|Channel 37||477.3250||Repeater Input||12.5 kHz|
|Channel 38||477.3500||Repeater Input||12.5 kHz|
|Channel 39||477.3750||General Chat Channel||12.5 kHz|
|Channel 40||477.4000||12.5 kHz|
|Channel 41||476.4375||Repeater Channel||12.5 kHz|
|Channel 42||476.4625||Repeater Channel||12.5 kHz|
|Channel 43||476.4875||Repeater Channel||12.5 kHz|
|Channel 44||476.5125||Repeater Channel||12.5 kHz|
|Channel 45||476.5375||Repeater Channel||12.5 kHz|
|Channel 46||476.5625||Repeater Channel||12.5 kHz|
|Channel 47||476.5875||Repeater Channel||12.5 kHz|
|Channel 48||476.6125||Repeater Channel||12.5 kHz|
|Channel 49||476.6375||General Chat Channel||12.5 kHz|
|Channel 50||476.6625||General Chat Channel||12.5 kHz|
|Channel 51||476.6875||General Chat Channel||12.5 kHz|
|Channel 52||476.7125||General Chat Channel||12.5 kHz|
|Channel 53||476.7375||General Chat Channel||12.5 kHz|
|Channel 54||476.7625||General Chat Channel||12.5 kHz|
|Channel 55||476.7875||General Chat Channel||12.5 kHz|
|Channel 56||476.8125||General Chat Channel||12.5 kHz|
|Channel 57||476.8375||General Chat Channel||12.5 kHz|
|Channel 58||476.8625||General Chat Channel||12.5 kHz|
|Channel 59||476.8875||General Chat Channel||12.5 kHz|
|Channel 60||476.9125||General Chat Channel||12.5 kHz|
|Channel 61||Reserved for Future Expansion||-|
|Channel 62||Reserved for Future Expansion||-|
|Channel 63||Reserved for Future Expansion||-|
|Channel 64||477.0125||General Chat Channel||12.5 kHz|
|Channel 65||477.0375||General Chat Channel||12.5 kHz|
|Channel 66||477.0625||General Chat Channel||12.5 kHz|
|Channel 67||477.0875||General Chat Channel||12.5 kHz|
|Channel 68||477.1125||General Chat Channel||12.5 kHz|
|Channel 69||477.1375||General Chat Channel||12.5 kHz|
|Channel 70||477.1625||General Chat Channel||12.5 kHz|
|Channel 71||477.1875||Repeater Input||12.5 kHz|
|Channel 72||477.2125||Repeater Input||12.5 kHz|
|Channel 73||477.2375||Repeater Input||12.5 kHz|
|Channel 74||477.2625||Repeater Input||12.5 kHz|
|Channel 75||477.2875||Repeater Input||12.5 kHz|
|Channel 76||477.3125||Repeater Input||12.5 kHz|
|Channel 77||477.3375||Repeater Input||12.5 kHz|
|Channel 78||477.3625||Repeater Input||12.5 kHz|
|Channel 79||477.3875||General Chat Channel||12.5 kHz|
|Channel 80||477.4125||General Chat Channel||12.5 kHz|
Previous UHF CB band plan (40 channels)
|Channel Name:||Frequency:||Purpose:||Frequency Spacing:|
|Channel 1||476.4250||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 2||476.4500||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 3||476.4750||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 4||476.5000||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 5||476.5250||Repeater Channel (Press DUPLEX to use) ('Emergency Use' only)||25 kHz|
|Channel 6||476.5500||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 7||476.5750||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 8||476.6000||Repeater Channel (Press DUPLEX to use)||25 kHz|
|Channel 9||476.6250||Simplex = General Chat Channel||25 kHz|
|Channel 10||476.6500||Simplex||25 kHz|
|Channel 11||476.6750||Simplex ('Call Channel' only)||25 kHz|
|Channel 12||476.7000||Simplex = General Chat Channel||25 kHz|
|Channel 13||476.7250||Simplex = General Chat Channel||25 kHz|
|Channel 14||476.7500||Simplex = General Chat Channel||25 kHz|
|Channel 15||476.7750||Simplex = General Chat Channel||25 kHz|
|Channel 16||476.8000||Simplex = General Chat Channel||25 kHz|
|Channel 17||476.8250||Simplex = General Chat Channel||25 kHz|
|Channel 18||476.8500||Simplex||25 kHz|
|Channel 19||476.8750||Simplex = General Chat Channel||25 kHz|
|Channel 20||476.9000||Simplex = General Chat Channel||25 kHz|
|Channel 21||476.9250||Simplex = General Chat Channel||25 kHz|
|Channel 22||476.9500||Simplex (Data Only, No Voice - No Packet)||25 kHz|
|Channel 23||476.9750||Simplex (Data Only (No Voice - No Packet)||25 kHz|
|Channel 24||477.0000||Simplex = General Chat Channel||25 kHz|
|Channel 25||477.0250||Simplex = General Chat Channel||25 kHz|
|Channel 26||477.0500||Simplex = General Chat Channel||25 kHz|
|Channel 27||477.0750||Simplex = General Chat Channel||25 kHz|
|Channel 28||477.1000||Simplex = General Chat Channel||25 kHz|
|Channel 29||477.1250||Simplex = General Chat Channel||25 kHz|
|Channel 30||477.1500||Simplex = General Chat Channel||25 kHz|
|Channel 31||477.1750||Repeater Input||25 kHz|
|Channel 32||477.2000||Repeater Input||25 kHz|
|Channel 33||477.2250||Repeater Input||25 kHz|
|Channel 34||477.2500||Repeater Input||25 kHz|
|Channel 35||477.2750||Repeater Input ('Emergency Use' only)||25 kHz|
|Channel 36||477.3000||Repeater Input||25 kHz|
|Channel 37||477.3250||Repeater Input||25 kHz|
|Channel 38||477.3500||Repeater Input||25 kHz|
|Channel 39||477.3750||Simplex = General Chat Channel||25 kHz|
|Channel 40||477.4000||Simplex||25 kHz|
It is proposed that equipment using 25 kHz spacing (40 channel equipment) be phased out by 2017. The ACMA plan to review this policy in 2016.
New Zealand offers a similar PRS service. New Zealand's Personal Radio Service (PRS) and 26 MHz Citizens Band radio are very similar to Australia's UHF Citizens Band and 27 MHz Citizens Band services.
The New Zealand Governments Ministry Of Commerce introduced the UHF PRS in 1996 to allow for freely available short-range wireless communications outside the 26 MHz CB band. The UHF (but not VHF) band was selected due to its ability to withstand atmospheric and groundwave interference unlike the existing 26 MHz allocation.
NZ PRS channels
- VMB4 Newcastle - An example of an Australian UHF CB Repeater
- Tropinet's UHF CB Repeater Listing - A database of UHF CB Repeaters Australia-wide.
- Jim Sinclair Radio Signal Finding McGraw-Hill Professional, 2000 ISBN 0-07-137191-5 page 281
- http://www.uhfcb.com.au/CB-Radio-History.php CB radio History
- Radiocommunications (Citizen Band Radio Stations) Class Licence 2002 - The Australian official license under which UHF CB operates
- Australian Communications and Media Authority - The Australian regulator of the radio-frequency spectrum
- General User Radio Licence for Citizen Band Radio - The Vanuatu official license under which UHF CB operates
- Citizen Band Radio Service (CBRS / CB Radio) or Public / Personal Radio Service (PRS) — Radio Spectrum Management Group (RSM), part of the New Zealand Ministry of Economic Development - The New Zealand regulator of the radio frequency spectrum
- Tropinet UHF CB Repeater Database for a listing of repeaters in Australia.
- UK CBers guide to Aussie CB radio - Detailed description of Australian CB service (including UHF) intended for UK CBers.