27Mhz HF CB

The 27 MHz CB service is capable of both local and interstate communication. However the latter cannot be relied upon. What 27 MHz can do depends on the transmission mode (AM or SSB) see modulation for more information, with SSB providing better results when signals are weak and/or over long distances. Locally, expect communication distances of between 5 and 15 kilometres on AM. Actual range achieved will depend on antenna efficiency, terrain and interference levels. Well-equipped home stations will do better than a mobile station. On SSB, distances of between 15 and 30 kilometres are common, with 3000 km sometimes possible under favourable conditions. Good conditions are often called 'skip', so-called because the signal bounces ('skips') off the ionosphere on its way to the other station. Long-distance propagation is most common in December/January each year and throughout the year during times of high sunspot activity. In the last decade or so 27 MHz AM activity has declined enormously. These days, you'll have no problem finding a vacant channel; even in major cities it is common to flick through them all and hear nothing. Major retailers have stopped selling 27 MHz radios, so you will need to find one of the few specialised communications shops, haunt the pawnshops or peruse the local classifieds to find equipment for sale. Nevertheless AM remains suitable for groups desiring cheap car-to-car communications amongst themselves. If your interest is more recreational, you'll do much better if you get a set with SSB (i.e. LSB and USB settings) as well as AM. SSB maintains a significant 'hobby' following, with many operators erecting large beam antennas to allow interstate communications. CB is a public medium so be prepared to hear all types on the air!

27Mhz HF CB Mobile radio with SSB

27Mhz HF CB Portable radio

Pros Cons
Licence Free Public Service
Will work in Valleys and dense bush Rage over 50Km cannot be relayed on
Can talk long distances under some circumstances Hard to find equipment
Low cost Large Antennas needed
Can be interfered with by Power lines and storms
Hard to use for untrained persons

27Mhz CB Channels

Channel Uses Modulation
1 Conversations AM
2 Conversations AM
3 Conversations AM
4 Conversations AM
5 Conversations AM
6 Conversations AM
7 Conversations AM
8 Highway AM
9 Emergency AM/USB
10 4WD AM
11 Caling AM Channel (part of calling net) AM
12 Conversations AM
13 Conversations AM
14 Conversations AM
15 Conversations AM/LSB
16 Caling LSB Channel (part of calling net) LSB
17 Conversations USB/LSB
18 Conversations USB/LSB
19 Conversations USB/LSB
20 Conversations USB/LSB
21 Conversations USB/LSB
22 Convoy Channel AM/USB/LSB
23 Conversations USB/LSB
24 Conversations USB/LSB
25 Conversations USB/LSB
26 Conversations USB/LSB
27 Conversations USB/LSB
28 Conversations USB/LSB
29 Conversations USB/LSB
30 Conversations USB/LSB
31 Conversations USB/LSB
32 Conversations USB/LSB
33 Conversations USB/LSB
34 Conversations USB/LSB
35 Caling LSB Channel (part of calling net) LSB
36 Conversations USB/LSB
37 Conversations USB/LSB
38 Conversations USB/LSB
39 Conversations USB/LSB
40 Conversations USB/LSB

Emergency Situations

To call for help simply follow this procedure :

1. Select the emergency channel on your CB - channel 9 AM or SSB. Be aware some emergency Monitors may monitor other local channels in addition to, or instead of, the emergency channels. If no response is received, try other local channels.

2. Call "Any emergency monitor", this is "call sign or first name" calling any emergency monitor"

3. Give the Monitor time to answer if no response is received call again.

4. Respond with the nature of the incident, exact location and other information. The Monitor will ask you for the information that he/she needs in order to notify the required services.

5. Remember To Stay Calm!

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