Enjoyed this website? Please support it by starting your online shopping here: Amazon eBay (no extra cost).
Return to VK3YE index page
|
Outback & Marine Communications
Outback Communications
Good communications is vital for the outback traveller, who may venture hundreds of kilometres from assistance. Its most important use is to summon assistance in the event of accident, illness or
vehicle breakdown. Other uses include obtaining advice on road conditions, advising trucks of your presence or maintaining communications within a convoy.
The following are the main choices available:
UHF CB is very popular amongst those who travel on major highways. It is economical and provides excellent local communication, particularly over flat terrain. It is also widely used by farmers
and truck drivers, increasing the likelihood of getting help. UHF CB gives car-to-car communication up to about 20 kilometres, depending on terrain. Where repeaters are available, communication can be extended to 100km or more.
The main deficiency of UHF CB is its limited coverage. In really remote spots there may be no radio-equipped vehicles within range of a typical UHF CB. This is why serious outback travellers carry both a UHF CB and an alternative for long-distance communications, such as HF radio
or a satellite phone.
HF radio
HF radio is the most popular choice for serious outback travellers. It requires a powerful vehicle-mounted transceiver and antenna. HF transceivers use a selection of fixed frequencies, which allow communication up to several thousands kilometres throughout the day. When teamed up with a UHF CB, effective communication over short, medium and long distances become possible.
An HF radio user requires a licence from the Australian Communications and Media Authority. If equipped with the appropriate frequencies, users are able to call the Royal
Flying Doctor Service. More routine communication, including passing messages to family members is available to members of the non-profit Australian 4WD Radio Network and others.
Suitable HF radios cost a few thousand to buy and install. Alternatively they can be hired. Availability of such equipment is limited to a small number of outback communications suppliers.
Satellite phone
Satellite phones allow communication to the standard telephone network. They are smaller than HF transceivers and are less susceptible to radio drop-outs that occasionally affect HF signals. Because of their high initial price and call charges, satellite phones are beyond the
scope of most recreational travellers. They also suffer from the disadvantage of not permitting radio contact with others in the area, as is possible with UHF CB and HF radio.
Marine Communications
There are three main types of marine radio communications equipment. It is important to choose carefully as one type cannot communicate with the other. Radio remains necessary as mobile phones have a limited range off shore.
27 MHz marine
Often mistakenly called 'marine CB'. The low-cost of equipment (around $150) made 27 MHz AM marine popular amongst recreational users in the 1980s and 1990s but activity fell in the 2000s. Communications range is up to 10 - 20 kilometres. AM marine is susceptible to interference from interstate and overseas due to ionospheric conditions. This equipment is covered by a 'class licence' so an operator licence is not required to use 27 MHz marine equipment. Note that 27 MHz marine and 27 MHz CB
operate on similar but not the same frequencies. This means that a 27 MHz CB operator cannot talk to a 27 MHz marine user.
The lowest cost form of marine radio communications for the casual user but now largely obsolete.
VHF marine
This is an international allocation around 156 MHz. Handheld and mobile-format radios have both got cheaper and more available so it is now much favoured over 27 MHz.
The greater power allowed and freedom from interference make VHF marine communications very crisp and clear. Communications range can extend up to 50 km, with repeater
stations available in some areas. Weather
reports are transmitted in many areas on VHF marine. Transceivers have fallen considerably in price and are now cheaper than 27 MHz marine transceivers used to cost.
Quality communications for the recreational or professional users who does not venture far off the coast.
HF SSB marine
HF SSB marine is used by ocean-going mariners. Though SSB communications is less clear than VHF FM, the low frequency allows communication over thousands of kilometres.
Equipment and antennas are more powerful, bulkier and more expensive than either 27 MHz or VHF
marine.
A must for ocean-going vessels, along with satellite phones.
In addition to the various types of radio transceiver mentioned above, are EPIRB beacons. EPIRB stands for Emergency Positioning International Radio Beacon System. These are small radio transmitters
that can be set off in an emergency. They operate on 406 MHz (VHF frequencies used by older EPIRBs have been phased out). EPIRBS can be received by aircraft, which report that a beacon has been set off.
Rescue crew are then sent to the area. Penalties apply for misuse.
Items were chosen for likely usefulness and a satisfaction rating of 4/5 or better.
|
Books by VK3YE
Ham Radio Get Started (USA)Australian Ham Radio Handbook (Aust) More Hand-carried QRP Antennas 99 things you can do with Amateur Radio Getting back into Amateur Radio Illustrated International Ham Radio Dictionary Make your Passion Pay (ebook writing)
All material on this site |