UHF RADIO

The Citizen Band Radio Stations (CBRS) is a two-way, short distance, voice communication service that provides a cheap, reliable means of communication.

The service operates in two frequency bands:

• High frequency (HF) – (26.965 – 27.405 MHz) rare now days.
• Ultra high frequency (UHF) – (476.4125 – 477.4125 MHz) our club radios.

UHF radios use Frequency Modulation (FM) and have become the preferred mode of operation for most.

In Australia, although there is no individual licence needed to use this equipment, it is still governed by the Citizens Band Radio Stations Class Licence and the Radio Communications Act. Under this Federal legislation certain channels have been reserved for specific use. Some other channels have also been designated for certain uses by general agreement.

CHANNEL and FREQUENCY	DESIGNATED OR ACCEPTED USE	CHANNEL and FREQUENCY	DESIGNATED OR ACCEPTED USE
1 – 476.4250	Duplex – Repeater Output	41 – 476.4375	Duplex – Repeater Output
2 – 476.4500	Duplex – Repeater Output	42 – 476.4625	Duplex – Repeater Output
3 – 476.4750	Duplex – Repeater Output	43 – 476.4875	Duplex – Repeater Output
4 – 476.5000	Duplex – Repeater Output	44 – 476.5125	Duplex – Repeater Output
5 – 476.5250	Duplex – Repeater Output  (Emergency use only)	45 – 476.5375	Duplex – Repeater Output
6 – 476.5500	Duplex – Repeater Output	46 – 476.5625	Duplex – Repeater Output
7 – 476.5750	Duplex – Repeater Output	47 – 476.5875	Duplex – Repeater Output
8 – 476.6000	Duplex – Repeater Output	48 – 476.6125	Duplex – Repeater Output
9 – 476.6250	Simplex	49 – 476.6375	Simplex
10 – 476.6500	Simplex – 4WD – Convoy, Clubs and National Parks	50 – 476.6625	Simplex
11 – 476.6750	Simplex – Call Channel	51 – 476.6875	Simplex
12 – 476.7000	Simplex	52 – 476.7125	Simplex
13 – 476.7250	Simplex	53 – 476.7375	Simplex
14 – 476.7500	Simplex	54 – 476.7625	Simplex
15 – 476.7750	Simplex	55 – 476.7875	Simplex
16 – 476.8000	Simplex	56 – 476.8125	Simplex
17 – 476.8250	Simplex	57 – 476.8375	Simplex
18 – 476.8500	Simplex –  Caravan and Convoy Channel	58 – 476.8625	Simplex
19 – 476.8750	Simplex	59 – 476.8875	Simplex
20 – 476.9000	Simplex	60 – 476.9125	Simplex
21 – 476.9250	Simplex	61 – Reserved for Future Expansion
22 – 476.9500	Data only – No voice	62 – Reserved for Future Expansion
23 – 476.9750	Data Only – No voice	63 – Reserved for Future Expansion
24 – 477.0000	Simplex	64 – 477.0125	Simplex
25 – 477.0250	Simplex	65 – 477.0375	Simplex
26 – 477.0500	Simplex	66 – 477.0625	Simplex
27 – 477.0750	Simplex	67 – 477.0875	Simplex
28 – 477.1000	Simplex	68 – 477.1125	Simplex
29 – 477.1250	Simplex – Pacific (NSW) Hwy Channel	69 – 477.1375	Simplex
30 – 477.1500	Simplex	70 – 477.1375	Simplex
31 – 477.1750	Repeater Input	71 – 477.1625	Repeater Input
32 – 477.2000	Repeater Input	72 – 477.1875	Repeater Input
33 – 477.2250	Repeater Input	73 – 477.2125	Repeater Input
34 – 477.2500	Repeater Input	74 – 477.2625	Repeater Input
35 – 477.2750	Repeater Input   (Emergency use only)	75 – 477.2875	Repeater Input
36 – 477.3000	Repeater Input	76 – 477.3125	Repeater Input
37 – 477.3250	Repeater Input	77 – 477.3375	Repeater Input
38 – 477.3500	Repeater Input	78 – 477.3625	Repeater Input
39 – 477.3750	Simplex	79 – 477.3875	Simplex
40 – 477.4000	Simplex – Highway Channel	80 – 477.4125	Simplex

Channels 1 to 8 and 41 to 48 – Repeater Channels.  Press the DUPLEX button on your radio to use any available repeaters. 

Channel 22 and 23 – Data transmissions only (No Voice)

Channels 31 to 38 and 71 to 78 – Repeater inputs – Do not use these channels for simplex transmissions as you will interfere with conversations on channels 1 to 8 and 41 to 48.

Channel 5 and 35 – Emergency use only – Monitored by Volunteers. No general conversations are to take place on these channels.

As at January 2007 the maximum penalties for the misuse of the legally allocated CB emergency channels are:

• For general misuse – if an individual 2 years imprisonment, otherwise $165,000 (a $220 on-the-spot fine can be issued in minor cases); or
• For interference to an Emergency call – if an individual 5 years imprisonment, otherwise $550,000

If you are considering a trip into any remote area, then a UHF Radio is an important communications device to have. Besides the entertainment value, such as chatting with other vehicles, this radio can be a valuable safety tool.

Since UHF signals travel in a straight line, the terrain plays an important part in how well the signal is transmitted or received. For example, the transmission will perform quite poorly if the signal is blocked by hilly or heavily forested areas. On flat terrains such as open countryside, distances between 5 and 20km may be achieved. Distances of up to 100km can be achieved if one or both UHF CB units are elevated on say a hilltop. UHF signals are less prone to power line noises and also provide clear and crisp communications.

UHF radios provide FM quality, short range, line of sight communications and are excellent for convoys. In general, a UHF radio is not of much use in an emergency unless someone happens to be in range of your location – usually much less than 50km. Handheld units are useful because you can walk to higher ground and greatly extend the range if the vehicle is in a valley, or the battery is flat. Owning a pair of handhelds is also useful for bushwalking or in just about any situation you can imagine. In areas where repeaters are installed communication up to many hundreds of kilometres is possible. They are popular in pastoral country with stations operating on public and private repeaters.

Most, if not all modern UHF CBs can scan all channels and lock in on a channel when a signal is heard. This overcomes the problem of not knowing which channel the repeater or the homestead is operating on.

Repeaters

UHF repeaters are special transmitting/receiving stations that are usually located in high areas to allow extended coverage. These stations, which are usually owned by businesses, farmers and clubs, allow UHF users to use them to re-transmit their signal. It works when you press your microphone button with the “Duplex or Repeater” button selected also. You must transmit between channels 1 to 8 and 41 to 48 because the “Duplex or Repeater” selection will add 30 channels and will now transmit to channels 31 to 38 and 71 – 78 on the repeater. The repeater, which collects the signal on 31 to 38 or 71 to 78, then switches to its output channel 1 to 8 and 41 to 48 to transmit simultaneously to say another radio user who may be some distance away or out of line of sight for instance on the other side of the hill.

This can be hard to grasp but imagine a device that needs two frequencies to work and it needs to keep these input and output frequencies as far apart as possible to allow the simultaneous receive and transmit (i.e. 31 to 38 for the repeater’s input and 1 to 8 for the repeater’s output). The further apart these two frequencies, the easier it is to keep the transmitter circuitry from interfering with the receiver circuitry. Therefore, you should not transmit to a repeater on channels 31 to 38 or 71 to 78. Please respect the fact that repeaters are erected and maintained by private individuals and you should keep the usage relatively short.

Microphone Usage

When speaking on your radio hold the microphone approximately 15 centimetres from your mouth (not too close, not too far) press the Push To Talk (PTT) button, wait 1 second and then speak in a normal voice.

If your chosen channel is in use or another person is talking across your conversation just select another channel. Do not provoke troublemakers who may deliberately search out other people to provoke a reaction, just ignore them. 

Twin Rivers 4×4 Club Channel is:-   9 (Nine)