ACBRO Team Inc 1980 - Advocates For Australian CB Radio Clubs And Operators

ACBRO Team Inc (CB Radio)

Australian Association Of Citizens

And Band Radio Operators Inc 1980

For The Beginner

(For further information and a comprehensive guide on CB radio operation in Australia, ACBRO have produced a publication that can be viewed on the Internet, click here.)

Brief Acceptable Operational Procedures

There are two "bands" allocated to the Citizens Band Radio Service (CBRS), the HF band 27 MHz., and the UHF band 476/77 MHz. (These bands are described in more detail following this article, below.) The HF band is known to be very noisy in respect to interference and the like, which in some cases can obliterate transmission reception, but the signals on this band will travel much further than on UHF. The UHF band in contrast, provides much clearer reception, but the signals travel on a line of sight basis with hence, limited range. The CBRS is a service, that despite being under the control of a government authority with powers to enforce the radio regulations covering these bands, is one that has to operate under a self regulatory basis. That is, the users have a part to play in controlling their use of the service in a sensible fashion in accord to fair play and the traditions under which the service has been established. In any form, of self regulation, problems can occur, and their resolve is only as good as the participants involved. So the first suggestion for the newcomer in setting up a station, is to spend a lot of tine just listening. Hear some of the traditional operations, note that some of the operators you may hear appear to be non-conformists, and learn to recognise bad operation, and decide that yours will be modelled on better lines.

It is traditional and useful to have a callsign. These used to be issued by the authorities when a station was had to be licensed, but now, with the a "class" license covering a CBer's operation, no licenses or fees are applicable. So establish your own callsign; if you are a member of a radio club, perhaps the group will have a system of issuing one. This is the case when joining ACBRO, a membership card is given displaying your callsign related to your membership number, i.e. ACBRO 456. By using the callsign you become recognised accordingly, and it obviates the need to transmit personal details such as your surname and address. That is, just use your "handle" (first name) and your suburb to provide a location when perhaps a asked, "What is your ten-twentys?," (location) or from the "Q" code, "what is your QTH?"

Now equipped with a callsign, you may wish to go to air. Your first contact may be by breaking in on others on a channel who are having a chat. If so, press the transmit switch on your microphone and announce yourself such as, "Breaker, breaker," and perhaps followed with your callsign. This should be done at the conclusion of the person's transmission you are hearing. Good or experienced operators often leave a pause of one or two seconds. In being acknowledged, await the invitation to go ahead, then identify yourself with your callsign and first name (handle), and say what you have to say, that is,
courteously make an enquiry or whatever and avoid wasting the other person's time, as you are the intruder. If you have presented yourself well, you may be invited to stay on the channel an participate as a group; this is how many longstanding friendships have been made on C B radio.

On the other hand, you may wish to use the call channel to establish a contact, in which case you can transmit a short call thereon, announcing your callsign such as "This is (callsign) looking for a copy (or contact." If you have a friend who monitors the call channel, and you wish to call him/her, this can be done in a simple fashion by announcing his callsign followed by yours (note - his first, yours last.) Hence a short call such as, "ACBRO 205, this is ACBRO 456 calling." Keep it as brief as possible to avoid disruption to the many who monitor the call channel. If having gained a response from the station being called, invite him/her to go to a channel to continue your chat. To select a channel for your use, you should seek a channel which appears to be free, and enquire on it whether the channel is in use. If no response is heard, If no response is heard, you may assume it is free to be used, and if so, tradition permits that you and your colleague may use it until your chat is completed, when it is said that you have gone clear.

You should be acquainted with the channel allocation, (channel allocation is described in detail following this article, below,) and respect the call channel and the emergency channel for being used only for their purposes Also, on the UHF bend, you should avoid disruption to the channels allocated for repeater use. So if you were to have a "simplex" chat to a friend, (that is a chat not using the repeater facility,) to quickly select a channel from Ch. 12 to Ch. 30 allows plenty of scope to find one that is free for use. Keep in mind that no one can claim title to any of the channels, they are there to be shared, but consideration to others should be given if usage is required during a very busy period, or when the "skip" (long distance) transmissions are taking place on the HF band.

On both bands a channel has been allocated to "Road use." This is not a regulated channel, but a recommended channel for a specific purpose, and is found to be very useful for motorists, who by experience, monitor it while travelling on country roads in particular, and keep themselves abreast with road information that may be given by other users. It is recommended by ACBRO that CBers in general respect the use of this and permit it to be used for its designated purpose.

Two Classes Of CB Bands

27 MHz HF BAND

The HF (High Frequency) Band offers two modes of operation and are not compatible with one another, AM (Amplitude Modulation) and SSB (Single Side Band). For this reason the AM mode is encouraged to be used on channels 1 to 14 and the SSB mode on 15 to 40. Although the AM mode can be very noisy in signal, one can expect communication distances of around 5 to 10 kms in normal operating conditions. SSB mode basically, has greater transmitting ranges. Distances of 15 to 50 kms can be reached under normal conditions and provides for a much better reception. Under ideal atmospheric conditions incredible distances are possible in both modes. This is called "skip." In skip conditions (where the signal travels upwards at an angle and bounces back to earth at the same angle) transmission distances can reach thousands of kilometres enabling one to communicate across the world.

476/477 Mhz UHF BAND

UHF (Ultra High Frequency) transmissions are made in the FM mode and offers a very clean and clear reception as opposed to the AM or SSB modes. It has become the preferred mode of operation for many. Because UHF signals travel in a straight line, geography plays an important role in how well a signal is transmitted and received. Any hill or man-made structure between one radio and the other will impede the signal. UHF has been made very popular; particularly in the flat country areas, and has become more so with the introduction of repeaters (described below) over the years enabling even further distances for communications. Under ideal conditions, distance of 200 kms or more can be reached. UHF radios can be bought with extensive features such as selcall, CTCSS and telemetry and telecommand systems (described below.)

Operational Facilities

UHF REPEATERS

UHF Repeaters are special stations that are mostly owned by businesses, farmers and clubs and are situated in cities and rural areas on the highest points available. Their main function is to increase the communications range between sets at great distances. A signal received by it from a UHF set on a repeater output channel, even if it is weak and noisy, is instantly re-transmitted at full strength to another UHF set's input channel. The higher a repeater is situated the more operators that can access it and the greater the area it can relay signals - up to 500,000 square kms or more. Conversations can take place on repeater channels (but not the emergency channel, 5). There are more operators than repeaters, so co-operation is needed for repeater channels to function amicably. Calls should be kept short and repeater usage respected because private individuals erect and maintain them for everybody's use at their own expense.

CTCSS

A radio with a Continuous Tone Coded Squelch System (CTCSS) on UHF, relies on receiving a sub-audible tone to open the radio's mute. When the radio is not in transmit mode it remains muted until it hears a transmission containing the same sub-audible tone and then opens up for communications. A radio fitted with CTCSS will ignore any signal on a frequency that does not contain the correct or same CTCSS tone(s). CTCSS prevents operators from hearing other users on the frequency that have non-CTCSS radios or whose radios having CTCSS, are not aligned on the same tone(s), although users with non-CTCSS radios will hear CTCSS users. Effectively, this provides for CTCSS users to communicate with each other for any length of time and never hear any "breakers" or being aware that they may have "jumped" on to a channel that is currently being occupied by non-CTCSS users. To use an analogy, it would be like two operators living next door to each other using radios to communicate with one another and having the squelch turned all the way up on both radios so as to "cut out" other stations from being heard by both parties. Everyone else will hear them, but they won't hear everyone else.

SELCALL

Selective Calling or selcall as it is known, operates in a similar fashion as CTCSS on UHF, with regards to "paging" another operator, but with one major difference. A radio with selcall remains muted until called by the appropriately coded tone. This opens the mute up on the radio (or activates an alarm) and the call is responded to by the operator from who ever was calling. The radio then, remains un-muted and while the conversation takes place on the particular channel between the parties, the radio operates as a traditional CB set in that operators of selcall systems will hear other users on the channel (regardless of whether those users have selcall or not,) just as those other users will hear the selcall operators.

TELEMETRY AND TELECOMMAND SYSTEMS

These terms describe the transmission of data and related information via a certain frequency. For example; a farmer may have a dam located on his property which may be 5 kilometres away from the comfort of his home. He may need to check the water level daily as well as switching on a pump in the morning to pump water to his home for consumption. The farmer may have been accustomed to riding out to the dam on his 250cc trial bike (or Harley Davidson) to switch the pump on and view the water level every day. Not anymore. He can now switch his pump on daily and have data transmitted to him on the water level by utilising telemetry and telecommand systems via specific frequencies on the UHF band. He would have a transmitter device electronically coupled to the pump switch and water level gauge and with a small antenna have information transmitted to him 5 kilometres away, in his home, to another transmitter device.

Frequency Allocation

For a detailed explanation of the usage of the
UHF - 476/477 Mhz - CB Channels please click here

or for a detailed explanation of the usage of the
HF - 27 Mhz - CB Channels please click here

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Channels 9, 11 and 16 on the HF band and Channels 5 and 11, 22 and 23 on the UHF band are protected by law for use only as designated. Severe penalties apply for operating a channel protected by law for anything other than what it is designated for. Voice communications is not permitted on UHF CB channels 22 and 23. Other channels are recommended for use as stipulated. Any channel not designated for a purpose is used as a communications channel for conversations. Conversations on repeater channels should be short and to the point. On the above HF channel allocation listing, channel 35 has been recommended as a secondary callingchannel by a CBer's self regulatory arrangement, as has the mode usage. (see above)

(For further information and a comprehensive guide on CB radio operation in Australia, ACBRO have produced a publication that can be view on the Internet. click here.)