UHF CB

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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.[1] 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. [2]

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.

Selective calling (Selcall)[edit]

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)[edit]

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[edit]

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.[3]

Channel use[edit]

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.[4]

Legally restricted channels[edit]

- 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[edit]

- 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.

- Channel 40 is often used for communicating with road users, including pilot/escort vehicles for oversized loads. [5] [6]


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[edit]

Expansion to 80 channels[edit]

On 27 May 2011 the channel spacing on UHF CB was changed, allowing the band to expand from 40 channels to 80 channels.[7] 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)[edit]

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 61 476.9375 Reserved for Future Expansion -
Channel 62 476.9625 Reserved for Future Expansion -
Channel 63 476.9875 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)[edit]

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[edit]

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

See also[edit]

References[edit]

External links[edit]