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UHF CB

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This is an old revision of this page, as edited by Didz (talk | contribs) at 01:44, 16 February 2011 (→Expansion to 80 Channels: 77 not 78 channels, the 3 channels not used are 61, 62 and 63.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

UHF CB is a class-licensed (meaning licence-free use for most users) citizen's band radio service authorised by the governments of Australia and New Zealand in the UHF 477 MHz band.[1] UHF CB provides 40 channels, including 16 channels (8 output, 8 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.

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 usually illegal to use these systems in Australia and New Zealand because they will interfere with other licensed services. Care must be taken with radios imported from overseas to ensure they comply with local regulations.

Repeaters

UHF CBs allow you to use the many publicly available repeaters around the country. They extend the range by retransmitting your voice usually from the top of a mountain or building. Sometimes a range of over 100 kilometres can be achieved by using a repeater. [2] See the UHF CB Australia website or Tropinet UHF CB Repeater Database for a listing of repeaters in Australia.

Selcall

Selcall allows radio to radio calling of UHF CB's by dialling their selcall number. Radios can be programmed to be completely silent until they are called. On radios which have this feature, received selcalls are usually indicated with a beep.

CTCSS

Use of CTCSS can be used which will silence a UHF CB until another radio with the same CTCSS code transmits. This permits monitoring of a channel for transmissions from radios within the same group without hearing other conversations that use different or even no tone.

Frequencies

Channel 11 is designated as the "Call Channel" to allow you to call other stations, however in many city areas local repeaters are used as the local call channel as they provide wider coverage.

Channel 40 is used Australia wide as the "Road Channel" extensively used by truck drivers for safety communications and traffic updates however due to interference between the New England and Pacific Highway communications, truck drivers between Sydney and Brisbane use channel 29 if they are travelling via the Pacific Highway.

Channel 18 is used for "Caravan & Motor Home" users Australia Wide.

Users should not use channels 31 to 38 as they are the automatically selected "Transmit" channels for repeaters on channels 1 to 8. Users who wish to use a repeater should choose a channel between 1 and 8 and press their "Duplex" button.

Channel 5 and 35 are for Emeregency use only

Channel 22 and 23 must never be used for voice communication

UHF CB Channel Allocations
Channel Frequency Purpose
1 476.425 Repeater Channel (Press DUPLEX to use)
2 476.450 Repeater Channel (Press DUPLEX to use)
3 476.475 Repeater Channel (Press DUPLEX to use)
4 476.500 Repeater Channel (Press DUPLEX to use)
5 476.525 Repeater Channel (Press DUPLEX to use) (EMERGENCY ONLY)
6 476.550 Repeater Channel (Press DUPLEX to use)
7 476.575 Repeater Channel (Press DUPLEX to use)
8 476.600 Repeater Channel (Press DUPLEX to use)
9 476.625 General Chat Channel
10 476.650 General Chat Channel
11 476.675 Call Channel - used in areas with no repeaters - To call other stations.
12 476.700 General Chat Channel
13 476.725 General Chat Channel
14 476.750 General Chat Channel
15 476.775 General Chat Channel
16 476.800 General Chat Channel
17 476.825 General Chat Channel
18 476.850 Caravan, Campers & 4WD Road Channel
19 476.875 General Chat Channel
20 476.900 General Chat Channel
21 476.925 General Chat Channel
22 476.950 Telemetry and Telecommand Only
23 476.975 Telemetry and Telecommand Only
24 477.000 General Chat Channel
25 477.025 General Chat Channel
26 477.050 General Chat Channel
27 477.075 General Chat Channel
28 477.100 General Chat Channel
29 477.125 Road Channel (Pacific Highway between Sydney and Brisbane only)
30 477.150 General Chat Channel
31 477.175 Repeater Input Channel (Not for use - See Below)
32 477.200 Repeater Input Channel (Not for use - See Below)
33 477.225 Repeater Input Channel (Not for use - See Below)
34 477.250 Repeater Input Channel (Not for use - See Below)
35 477.275 Repeater Input Channel (EMERGENCY ONLY)
36 477.300 Repeater Input Channel (Not for use - See Below)
37 477.325 Repeater Input Channel (Not for use - See Below)
38 477.350 Repeater Input Channel (Not for use - See Below)
39 477.375 General Chat Channel
40 477.400 Australia-Wide Road/Truckies Channel (excluding Syd->Bris via Pacific Highway where 29 is used.)

Expansion to 80 Channels

A new plan was released by ACMA in early May 2010 with a total of 77 channels. Two will be data only telemetry channels, with voice not permitted, as currently on UHF 22 and 23.[3]

The 2 Emergency Channels 5 and 35 will not change. These are intended for Emergency use only, by law.

These changes will be in place from early 2011.

See also

References

  1. ^ Jim Sinclair Radio Signal Finding McGraw-Hill Professional, 2000 ISBN 0071371915 page 281
  2. ^ http://www.uhfcb.com.au/CB-Radio-History.php CB radio History
  3. ^ "UHF CB to expand to 80 channels". ACMA. 2009. Retrieved 2010-07-07.
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