The Citizen Band Radio Service (CBRS) is a two-way, short distance, voice communications service that provides a cheap, reliable means of communication.
The service operates in two frequency bands: 27 MHz and 477 MHz UHF.
27 MHz is an AM transmission while 477 MHz UHF CB is an FM transmission and gives clear, crisp local communication without long-distance interference.
What are common channels to use?
There are a total of 80 channels available with UHF CB, so there should always be channels free of conversation to use. Some of the channels have been allocated for specific uses.
– Ch 5 should only be used for emergencies
– Ch 11 is the officially designated call channel to link up with specific people before moving off to another channel to communicate
– Ch 22-23 are designated telemetry/Selcall channels and voice transmission is inhibited as required under the standard – AS/NZS 4365.2010
– Ch 1~8; 31~38 are used for communicating with repeaters and radio must be used in duplex mode
What is CTCSS / DCS?
Continuous Tone Coded Squelch System (CTCSS) is a means by which a receiving radio will remain silent until it receives a transmission that includes a special audio tone. As long as this tone is continuously received, you will be able to hear the person who is transmitting.
Digital Coded Squelch (DCS) is somewhat similar, but instead of sending a continuous tone of differing frequency, a Digital data transmission is added to the radio signal.
One method is not necessarily better than the other. The radios you are using have to have the same ability to send and receive the same coding signal, no matter which of the two you use.
The function of CTCSS or DCS is to keep you from hearing others, not to keep others from hearing you.
What is Voice Inversion Scrambler?
User selectable, will make your voice unintelligible to others not using the same scrambler technology, providing a new level of privacy.
What is SelCall?
Selcall (selective calling) is a type of squelch protocol used in radio communications systems, in which transmissions include a brief burst of sequential audio tones. Receivers that are set to respond to the transmitted tone sequence will open their squelch, while others will remain muted. Selcall uses the transmission of audio tones that are recognisable to receivers fitted with a compatible decoder.
What is Advanced Signal Management?
Identifies interference caused by strong local signals on adjacent channels and prevents these from opening your squelch control. Also minimises distortion of reception by fine tuning the receiver frequency to match that of the incoming signal. A unique GME feature that is critical to the optimum performance of 80 channel radios ensuring that incoming signals remain interference free, clear, and undistorted, even if they are slightly off frequency.
What is Dynamic Volume Control?
Modulation levels of signals can vary considerably resulting in noticeable differences in received volume between channels. With the introduction of 80 channel narrowband transmissions, the disparity in audio volume will increase further. GME’s DVC automatically compensates for variations in received audio level. When activated, this feature provides a constant audio output level greatly enhancing the quality of reception and the simplicity of use.
What is DSC?
Digital Selective Calling (DSC) is a means of sending pre-determined digital messages between stations over HF and VHF Marine radio systems. DSC transceivers are able to send distress alerts which include the vessel’s MMSI number and GPS location along with the time at which that location was determined. The radio operator can send an alert by a single press of a button and the alert will then repeat automatically.
Further information on GME transceivers with DSC functionality is available here:
VHF hand held radio
VHF fixed mount radio
What are Programmable Receive Channels?
Some radios have extra receive only channels, which means you will be able to program your radio to listen to these but you will not be able to talk on them.
What is Tail Cancelling?
Eliminates the squelch noise burst in a receiving radio by delaying the audio slightly.
Marine Frequencies – 27 MHz and VHF Explained
There are both technical and licensing differences between 27 MHz Marine Radios and VHF Marine Radios. 27 MHz radios are typically utilised on inshore waters, and have a maximum range typically between 8 and 16 km. VHF radios are both clearer and more powerful and are the radio of choice for offshore use. None the less, they can also be utilised for inshore applications. The maximum range of a VHF radio is typically up to 20 km between vessels or up to 50km from a shore base. (see: range of your signal on the water)
Another big advantage of VHF radios is that VHF communications are monitored by coast stations operated by rescue and other organisations. Vessels can set up logs between themselves and coast stations on coastal voyages, maintaining regular communication, and improving safety.
There are certain usage protocols which must be observed when using a Marine radio. These protocols enable search and rescue authorities to quickly and efficiently assess the situation and act accordingly. Inefficient use of communications equipment can, and does, affect the outcome of a problem on the water. Detailed information about the use of Marine Radios in Australia can be found at the Australian Communications and Media Authority (ACMA) website
Range of Your Signal on Water
There are two major factors which determine the range you will be able to transmit with your VHF radio. These are the transmission power of the radio itself, and the height of the antenna. VHF transmission is in a straight line. As a result, the curvature of the Earth forms a barrier which limits the distance you can transmit. By increasing the height of your antenna, you can increase the distance before the signal hits the horizon.
You can calculate the transmission distance achievable using the following formula:
Range=1.23√Antenna Height in Feet
So for a mariner using a handheld radio where the antenna is approximately 6 feet above the water, the achievable range is 3.01 nautical miles (5.57km). If the same mariner is talking to another mariner using a handheld radio where the antenna is approximately 6 feet above the water, the two distances are combined, giving a total of 6.02 nautical miles (11.14km).
If the mariner is talking to land base station with an antenna that reaches 400 feet above sea level, and using a fixed mount radio with an antenna that reaches 12 feet above sea level, the distance is far greater at 4.26 nautical miles plus 24.6 nautical miles. This gives a theoretical achievable distance of 28.86 nautical miles.
Other factors which can influence the actual achievable distance include transmission power of the radio, weather as well as obstacles such as islands and waves.
AIS – What is it?
Automatic Identification System (AIS) is a means of sending and receiving ship information such as identity, position, course, speed, ship particulars and cargo information to and from other ships, suitably equipped aircraft and shore. AIS is transmitted over the VHF band which ensures functionality even in foggy conditions and near obstacles where the performance of radar systems may be compromised. Applications for AIS include collision avoidance, traffic monitoring and control, aid to navigation and search and rescue.
Does the AIST120 send GPS positional information via the NMEA0183 output port?
The AIS cannot provide or output GPS positional information to other equipment via the NMEA 0183 output port. The NMEA output port only sends received AIS data to a compatible chart plotter using the NMEA protocol. The AIST120 includes an internal GPS receiver which independently receives GPS Satellite signals to develop the necessary GPS positional fix. The GPS positional data is attached along with Static-Data (MMSI,Vessel name, Vessel call Sign) when the AIS sends out a vessel Transmission signal.The AIST120 can only be configured to provide GPS positional output data via the USB port lead. The GPS positional data is available for use with laptop devices using charting software.
Can the AIST120 / AISR120 be wirelessly connected to a laptop or iPad using navigation software?
Not without integrating another device. Currently the AIST120 and AISR120 are supplied with a USB connection for direct AIS output messaging intoPC or MAC applications which operate with Navigation Software. There are products on the market which allow Tablets / Laptop / iPad users to be able to wirelessly interface with NMEA type electronic equipment. A ‘Wireless NMEA Multiplexer’ adaptor is designed to send the NMEA output data from the AIST120 / AISR120 via WiFi to the iPad. The NMEA output from both AIS products are standardised, thus if the Wireless adaptor allows data transfer without any loss/ or data drop-out, and the user has AIS compatible charting software loaded on the iPad, then it should be possible to wirelesslyconnect the units.
EPIRBs – Testing your EPIRB
Testing your EPIRB or PLB is important maintenance task which should form part of your regular safety equipment maintenance routine. A short video demonstrating how to test your EPIRB is located here
How does an EPIRB work?
When activated, an EPIRB transmits information identifying the unit (and therefore the registered owner) in a 406 MHz signal. The signal is relayed via the COSPAS/SARSAT satellite network to the Rescue Co-ordination Centre (in Australia: Australian Maritime Safety Authority, in New Zealand: Maritime New Zealand) where the most appropriate rescue response is initiated and co-ordinated.
If the unit is a GPS equipped EPIRB, the GPS location details are included within the 406 MHz transmission, giving rescue authorities an accurate location to an accuracy of about the size of a football field within minutes. Without GPS, the location is calculated by triangulation, which may take significantly longer. To learn more about the benefits of using a GPS equipped EPIRB watch our short explanatory video here
PLB vs. EPIRB– What is the difference?
The technology used in PLBs and EPIRBs is essentially the same, however there are differences due to the different ways in which these devices are intended to be used.
In Australia it is mandatory to carry a registered EPIRB on vessels travelling greater than 2 nautical miles offshore. An EPIRB is designed to operate at full power for a minimum of 48 hours. It must be self buoyant, and float in an upright orientation with the antenna clear of the water. This enables the user to tie the EPIRB (using the supplied lanyard) to a life raft or similar and let the EPIRB float in the ocean with a clear view of the sky whilst taking shelter within the raft.
My EPIRB battery is due to expire, what will it cost to refurbish my beacon and where do I send it to?
The cost will differ depending on the model, please refer to table below. All Beacon refurbishments are performed only by GME head office GME Sydney Service Centre, 17 Gibbon Road, Winston Hills, NSW 2153. Click the following link for more details regarding refurbishment, ie: freight cost and turnaround.
Beacons are detected world-wide by the global satellite system, COSPAS-SARSAT, and are detected from anywhere on the Earth’s surface if they are deployed correctly. It is recommended you contact your chosen airline for guidance on carrying distress beacons as every airline and airport have differing requirements. Please also note that some countries consider Personal Locator Beacon (PLB) carriage and activation illegal on land. Refer to the COSPAS-SARSAT website for the appropriate SPOC (search and rescue or SAR point of contact) for the country you are travelling to and contact them to confirm you are legally allowed to use your beacon. It is worth noting that the search and rescue response in each country will vary due to different levels of SAR resources and capability. It is recommended that you check locally the sort of SAR response you can expect. This will also depend on the weather conditions at the time the search and rescue is being conducted e.g. day, night, visibility (low cloud, fog, snow), high winds etc. The rescue coordination centre of the country where the beacon is detected will coordinate the search and rescue response, not Australia. AMSA Search and Rescue will only provide the registration details, if known, and any other information it gathers from emergency contacts. AMSA will request information on the progress of the search and rescue.
What is the difference between a Non-GPS equipped and a GPS Equipped EPIRB or PLB?
When activated in an emergency, a GME GPS equipped EPIRB firstly obtains its GPS location from the GPS satellite network. This location is then coded into the signal that the EPIRB sends to the COSPAS/SARSAT search and rescue satellite network. Armed with this vital information the rescue Coordination Centre (RCC) knows exactly where to send resources for a fast, effective response. Without GPS technology, the process of calculating a location and search area could take hours, and that’s before a rescue vessel or helicopter has been launched. In a life and death situation, time is everything.
How far will my Two-Way radio transmit?
It’s often difficult to provide a definitive answer regarding the actual ‘distance’ achieved by a mobile or handheld without obtaining some other perspective.
In the majority of applications the ability of a portable or mobile radio to transmit/ receive an effective RF signal over a given distance will be always determined by the radio Transmit output power, the antenna height/gain and the surrounding landscape.
In the majority of applications the ability of a portable or mobile radio to transmit/ receive an effective RF signal over a given distance will be always determined by the radio Transmit output power, the Antenna height/gain and the surrounding landscape.
To obtain a general idea of the expected range we would need to create an ‘ideal’ condition, for example let’s take two 5 watt mobiles fitted in vehicles with similar antennas mounted 1.5 m above ground (typical bull bar height) and travel along a flat open highway (line of sight) until each radio is no longer able to receive. The distance achieved will be the point where the radio no longer receives a signal. Thus a 5 watt transceiver placed under these ‘ideal’ conditions is expected to achieve up to 7-10 kms.
However if the conditions were to change and one radio went to higher ground the range would be extended. If the conditions were unfavourable and Line of Sight was restricted (built up areas / buildings / hills and valleys / forests, etc.) the range would be reduced.
In areas where range is difficult to achieve it would be advisable to utilise the local repeater. Many local repeaters are often positioned in high areas of certain city/ country locations which extend the range between radios. UHF CB channels used for repeater operation are found between Ch1- 8 and Ch41-48.
Will shortening the Antenna coaxial cable affect the performance?
If the coaxial cable is cut and joined correctly there will be minimal effect on the overall performance. Our aerial bases are supplied and fitted with 4.5 meters of 50 ohm coaxial cable, at UHF 477 MHz high-end frequencies the effects imposed from a shorter length of coaxial cable is minimal.
However it must be understood that coaxial cable is a form of transmission line and comprises of an inner core surrounded by a braided shield which is isolated by a plastic layer. To maintain the integrity and performance after the cable has been cut the cable must be rejoined using coaxial connectors.
A male PL259 connector is the standard connector used for two-way radio, there is a recommended instruction sheet available from our web site here.
In situations when the coaxial cable is cut and joined a male PL259 connector is required at each open end and connected together by a female in-line adaptor. The connectors and adaptor should be finished and sealed using ‘self amalgamating tape’
Important: We advise customers any damage caused by the work carried out on the product will void the warranty,
Which is the best type of Antenna for my vehicle?
We recommend before deciding on which antenna is the best for your vehicle you may want to ask yourself what conditions and time you will be spending most of your driving.
Typical driving conditions may include driving around town, open highway driving, or heavy off-road driving.
We have many variations of antennas in our range which are suitable however our AE4018Kxx series is considered the most popular and good all round performer and usually the favoured antenna for city-country driving whereas for outback off-road conditions the AE47xx fibreglass raydome series are robust and can endure the harsh environment.
All our antennas are operable in various conditions and in most applications the design and construction of the antenna tends to determine where they are most suitable.
Can I connect my GME handheld radio to an external antenna?
Yes, however it will depend on the model, the majority of GME portables are fitted with either an SMA or TNC antenna connector. To successfully connect an external antenna to your handheld will require a suitable inline adaptor. Our antennas are currently supplied with a standard PL259 male connector which is fitted onto the coaxial cable at the time of installation.
A compatible adaptor will allow the external antenna plug to connect with the handheld. The following adaptors are compatible with our handheld radios. AD407 (SO239 to TNC) / AD020 (SO239 to SMA).
What do the LED colours mean on my TX6150 Twin-Charger (BCD014)?
Initially when the BCD014 is applied with power (no batteries) both LEDs will flash Red > Green > Amber > OFF
Single Battery pack charging
When a Battery is placed in Front pocket only( nil in rear pocket) the LED will glow Red to indicate the Battery is Charging. When the Front LED switches to Green the Battery is fully Charged. When a Battery is placed in Rear ONLY, (nil in front pocket) the ‘Rear’ LED will glow Red to indicate the Battery is Charging. When the ‘Rear’ LED switches to Green the Battery is fully charged.
Two Battery packs charging
(Note: FRONT Battery always has priority, the BCD014 only charges one battery at a time). The FRONT Battery will begin Charging indicated by a solid Red LED, the REAR Battery is on Standby shown by a solid Amber LED. When the FRONT Battery has fully charged the LED will switch from RED to GREEN, the Rear LED will then switch from AMBER to RED to indicate charge. When BOTH batteries are fully charged, Both LEDs will show GREEN. The average charging time for a BP015 battery pack is approximately 3.5 hours. To obtain a proper charge it is recommended radios are switched off.
Where are you located and what are your opening hours?
The GME Head Office is located at; 17 Gibbon Road Winston Hills NSW, 2153 Australia
Opening hours are between 8:30am to 5pm Monday to Friday (AEST / AEDT).
Our head office can be contacted on +61 2 8867 6000.
Can I purchase directly from GME?
GME does not sell direct to the public. We have an extensive list of authorised GME Distributors and Stockists across Australia. To find your nearest GME Stockist, please click on the following link and enter your postcode.
Do you have authorised GME repairers who can fix my radio?
GME has several Authorised Repairers across Australia. To find your nearest GME Authorised Repairer, please contact 1300 463 463 between 8:30am to 5pm Monday to Friday (AEST / AEDT).
GME Professional FAQs
Can I use any microphone with the CM60 Local Control and Remote Control models?
We recommend utilising the GME MP600B microphone for all Local Control and Remote Control models. The MP600B has been optimised for the design and operation of our Local Control and Remote Control configurations of the CM60 Professional Radio platform.
The CM60 Professional Radio Series has been developed for mission critical applications, as such, non-compliant components are not recommended to be used. Any usage of non-compliant components will result with GME not being able to guarantee that the system will comply to specification if operating outside the recommended configuration. Also, any non-compliant usage which includes operating outside the recommended configuration may impact our manufacturer’s warranty.
For any further information please contact 1300 463 463 or email us firstname.lastname@example.org