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Amateur Radio Q-Codes

The Q-Code is a standardised collection of three-letter message encoding, also known as a Brevity Code, (Brevity Codes are used in amateur radio, maritime, aviation and military communications. The codes are designed to convey complex information with a few words or codes, all of which start with the letter “Q”), initially developed for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio. Although QCodes were created when radio used Morse Code exclusively, they continued to be employed after the introduction of voice transmissions. To avoid confusion, transmitter call signs are restricted; while an embedded three-letter Q sequence may occur (for instance when requested by an amateur radio station dedicated to low-power operation), no country is ever issued an ITU prefix starting with “Q”, (The International Telecommunication Union [ITU] allocates call sign prefixes for radio and television stations of all types). The codes in the range QAA–QNZ are reserved for aeronautical use; QOA–QQZ for maritime use and QRA–QUZ for all services.

Early Developments

The original Q-Codes were created, about 1909, by the British government as a “list of abbreviations… prepared for the use of British ships and coast stations licensed by the Postmaster General. The Q-Codes facilitated communication between maritime radio operators speaking different languages, so they were soon adopted internationally. A total of forty-five Q-Codes appeared in the “List of Abbreviations to be used in Radio Communications”, which was included in the Service Regulations affixed to the Third International Radiotelegraph Convention in London (The Convention was signed on July 5, 1912, and became effective July 1, 1913.)

Later Usage

Over the years, modifications were made to the original Q-Codes to reflect changes in radio practice. Over a hundred Q-Codes were listed in the Post Office Handbook for Radio Operators in the 1970s and cover subjects such as meteorology, radio direction finding, radio procedures, search and rescue, and so on.

Some Q-Codes are also used in aviation and some in maritime. (A subset of Q-Codes is used by the Miami-Dade County, Florida local government for law enforcement and fire rescue communications, one of the few instances where Q-codes are used in ground voice communication.) Many military and other organizations that use Morse Code have adopted additional codes, including the Z-Code used by most European and NATO countries. Used in their formal “question/answer” sense, the meaning of a Q-code varies depending on whether or not the individual Q-code is sent as a question or an answer. For example, the message “QRP?” means “Shall I decrease transmitter power?”, and a reply of “QRP” means “Yes, decrease your transmitter power”. This structured use of Q-codes is fairly rare and now mainly limited to amateur radio and military Morse Code (CW) traffic networks.

Breakdown by Service •

QAA to QNZ – Assigned by the International Civil Aviation Organization (ICAO). •
QOA to QQZ – Reserved for the Maritime Services.
QRA to QUZ – Assigned by the International Telecommunications Union (ITU). •
QVA–QZZ – Are not allocated.

Amateur Radio

Selected Q-Codes were soon adopted by Amateur Radio Operators. In December, 1915, the American Radio Relay League (ARRL) began publication of a magazine titled “OST”, named after the Q-Code for “General call to all stations”. In Amateur Radio, the Q-Codes were originally used in Morse Code transmissions to shorten lengthy phrases and were followed by a Morse Code question mark (··–··) if the phrase was a question.

Q-Codes are commonly used in voice communications as shorthand nouns, verbs, and adjectives making up phrases. For example, an Amateur Radio Operator will complain about QRM (manmade interference), or tell another operator that there is “QSB on the signal”; “to QSY” is to change your operating frequency.

They can still be heard on HF communications but are not normally used on UHF and VHF communications. The reason is quite simple. Many radio amateurs have become certified purely to be volunteer communicators for their local emergency programs and consequently are not very familiar with the Q-Codes. Recently Q-Codes have again been used more for Morse Code communications than for voice communications.

 

3-in-1 Orange Pi Zero 512MB Development Board

I’m really excited about the Orange Pi Zero, and can’t wait for mine to arrive!! This little development board combo includes the Orange Pi Zero 512M, Expansion board and case. For $25.89AU landed (at time of writing), this combo provides a big punch for buck that’s great for all those little projects. It forgoes things like HDMI connectors, making it ideal for headless, embedded applications.

Under the hood it’s a H2 Quad-core Cortex-A7 H.265/HEVC 1080P, using a 1.2Ghz AllWinner H3 SoC, with 512MB DDR3 SDRAM. With a Mail400MP2 GPU humming along at 600Mhz with support for the industry standard OPENGL ES 2.0.

Network connectivity provides you with some great options, either old school 10/100M Ethernet RJ45 with POE!! Or WiFi with supported IEEE 802.11 b/g/n, via an XR819 antenna.

Power is via USB OTG with power switch. wile the board doesn’t consume much in the way of power, it’s recommended you use a 5V 3A PSU for your connected  peripherals.

Shop Links:

 

 

 

 

 

9-Code, 10-Code

Over the years, public safety dispatchers have developed a semi-standardized code for speaking on the radio. Although the trend during the past 10 years has been to use plain English for law enforcement and fire communications, many agencies still use codes on the radio. The code is known as “the ten code” because the actual code is preceded by the word “ten.” The origin and reason for this is unknown. However, it appears that the “ten” prefix was meant to signal that the numbers following are part of the code, and not an address, age, phone number, etc. Over the years, as more codes were added, the number of ten-codes ran out, and agencies began using “eleven” as a prefix. At some point, other agencies developed a nine-code that accomplished the same thing but used the number nine as a prefix.

The use of codes continues, despite some pressure to use plain English to assist in clarity and operations among different agencies. Once in a while a agency will announce they’re switching away from codes. But since many laws, ordinances and other regulations are stated in letter/number codes, many law enforcement agencies continue to use codes over-all.

We do know that the first published 10-Code was in the APCO Bulletin of January, 1940, after a meeting of the State Systems Standards Committee in Springfield (Ill.)–part of their Project 4 to develop developed “Ten Signal Cards.” There were only 17 codes in the first version, but it grew to about 60 after the list was first published. APCO also took a stab at standardizing codes back in 1973 as part of their Project 14 to make radio communications more concise. These codes includes those from 10-1 to 10-39, with an “optional” list of codes above 10-39. We don’t know of any original listing of these codes on the APCO Web site, but check here for the standard codes, and here for the expanded set.

In late 2005 FEMA established requirements for adoption of the National Incident Management System (NIMS), including a requirement that all public safety agencies routinely use plain English on the radio in order to qualify for any federal grants. However, after some hot debate, FEMA rescinded the order in Feb. 2006, saying plain English was only required when handling multi-agency, multi-jurisdictional incidents. Download (pdf) the explanatory letter.

In early 2009 several large agencies began the transition to plain English, including Dallas PD.

Despite attempts at standardization, there are probably 20 to 30 versions of the original 10-Code being used across the county. Even when an agency uses the standard list, they probably have customized a some of the codes for their own use. For each code we have tried to include the most common definitions. In this consolidated list, some codes have the same definition. Also, many agencies do not use all of the codes on this list, but rather just the few they need.

Many codes can be suffixed by the letter “x” to indicate that a female was involved, or other letters that specify more information (“A” for audible alarm, “S” for silent, etc.).

For this reason, it’s not advisable to memorize this list if you intend to study before becoming a dispatcher–your agency probable has its own list. However, it would be helpful to be familiar with the definitions and types of information that are usually condensed to code form.

Beginners Guide to Radio Scanners

If you’re a complete beginner/novice to scanning, I hope this guide will give you some useful advice and point you in the right direction to get you started.

This guide will be updated time to time to add new subjects and teach you more about your scanner and various scanning activities.

First off, I’ll start with the basics of what a scanner is and does in its simplest form.

The Basics

1: What is a scanner?

A scanner is a radio that covers a far wider frequency range than your average radio at home. Most radios you find in everyday use have a single purpose, i.e. the radio in your car/home is designed to only receive commercial radio stations. Scanners on the other hand, can receive signals transmitted on a wide range of frequencies, allowing the user to listen in to a huge range of different communications including air traffic control, emergency services (ambulance and fire), hobbyists (Citizens Band, Amateur radio), security guards, taxi’s and a lot more.

2: What does a scanner do?

A scanner has two main modes of operation; these are commonly known as ‘search’ and ‘scan’

In ‘search’ mode, you are searching for any transmissions within a certain frequency range specified by the user, i.e. 400-470 MHz. The scanner will quickly scan through the frequencies and if it detects a transmission it will stop immediately and let you listen to what it has found. At this point you can hold the scanner on this frequency and continue to listen or you can let it continue scanning for other transmissions. You can also store the frequency it stopped on into a memory channel for future reference. That brings me to the next mode on your scanner, ‘scan’

Once you start filling up your memory channels with frequencies of interest to you, you can set the scanner to scan through only the channels you’ve saved. This mode on most scanners is extremely quick so you never miss any action.

3: Types of scanners?

Scanners come in two types, handheld and base/mobile. Deciding which to buy is simply a case of knowing where you will use the radio most. If you only plan to use it at home, a home base unit would be a better option. If you plan to take your scanner out and about, a handheld unit will be the best option. Purchasing a handheld is probably the best option for beginners as you can use this at home and also outdoors so you get the best of both worlds.

Getting technical

Now that we’ve got what a scanner basically does, we’ll move onto some of the more technical aspects of scanning.

A lot of beginners seem to falter at this stage, they’ve bought a scanner, played around with it and can’t find anything to listen to and are disappointed and blame the scanner, when 90% of the time, it’s a user error, or just a lack of knowledge in regards to knowing where to scan and what to look for.

I’ll start with some of the other basic functions on a scanner, I’ll stick to the basics that every scanner will have, most scanners will have a lot more features but these will all be model specific.

1: Squelch

You need to set your squelch control properly for the scanner to search/scan. This is easy to do. To start off, turn the squelch right down so you get the constant hissing/white noise coming through the speaker, then slowly turn it back up, you want to set it just above the point where the hissing/white noise stops and that’s it, your squelch is set.

2: Modes

Nearly all scanners will have at least 2 modes, those being AM and FM. For the best part, you’ll be sticking to FM. There are some exceptions though, Air Band (108-136 Mhz) for example uses AM, so when searching through the air band range, make sure you’re using AM.

Some scanners will list FM as NFM and WFM, NFM stands for narrow fm and WFM stands for wide fm. You only need WFM for listening to commercial radio stations, for everything else stick to NFM.

There is also USB and LSB, upper and lower sideband, these modes are used mainly on the HF bands (3-30 MHz) by radio amateurs, ships, aircraft etc. You will only find these modes on more advanced scanners.

3: Step size

You’re scanner will usually have various step sizes for you to choose from (on cheaper/older scanners you may find these are locked and you have no choice) these will typically range from 5/6.25/8.33/10/12.5/25/50khz steps. Choosing the correct step size is essential for searching efficiently and making sure you don’t miss any transmissions, and also to make sure that when the scanner stops, it’s accurately tuned to the frequency.

A general guide is to stick to 12.5 kHz steps for VHF, and 6.25 kHz steps for UHF.

4: Scan delay

Most scanners will have an option for you to choose how long the scanner will stop on a frequency after the transmission ends, before it starts scanning or searching again. The times will vary from scanner to scanner, usually 2-30 seconds and it’s entirely up to you which you choose. This is a handy feature as the other radio user may take a few seconds to respond to the first person, so without this feature, the scanner would just immediately move on without waiting for the response.

5: Lock out

Again, this is a feature most scanners have. This enables you to lock out certain frequencies you want to skip past/ignore. In “search” this is useful as you will occasionally come across a transmission which is constantly there making the scanner stop, so instead of having to manually make the scanner continue, with the lock out feature the scanner will simply ignore it and continue scanning. In ‘scan’ mode, you might not want to listen to some of your stored channels while scanning through them, so if you lock them out, the scanner will ignore any activity found on them. Any channels locked out, can be unlocked at any time as well, refer to your manual on how to unlock the channels (usually just the same way you locked them to start with)

6: Hold

Most scanners have a ‘hold’ button, pressing this will indefinitely hold the scanner on the current channel/frequency until you press it again which is handy for monitoring one channel if something interesting is happening, this will ensure you miss nothing.

Using your scanner

Now that you have a basic understanding of what your scanner can do, and what the basic functions do, it’s time to put it to use.

You will need to refer to your scanners manual to find out how to get it into search mode (to find frequencies in your area) or scan mode (to scan frequencies you’ve stored)

Here is a rough guide of where to search and what you may find using your scanner.

31.000 – 32.000 MHz FM – Cordless phones

70.500 – 71.500 MHz AM – Fire Brigade

85.000 – 88.000 MHz – PMR (Private Mobile Radio)

117.975 – 136.000 MHz AM – Civil Air band.

144.000 – 146.000 MHz FM – Amateur Radio 2m Band

156.000 – 163.000 MHz FM – Marine band

163.000 – 185.000 MHz FM – PMR (security,taxis,ambulance etc)

200.000 – 399.000 MHz AM – Military airband

430.000 – 440.000 MHz FM – Amateur Radio 70cm band

440.000 – 446.000 MHz FM – PMR

446.000 – 446.500 MHz FM – PMR (including licence free pmr)

446.500 – 470.000 MHz FM – PMR (security etc)

It’s now simply a case of searching through the various ranges over and over and finding transmissions within range, listening to them and trying to identify them.

Have patience when you’re searching and don’t get frustrated if you pick up nothing the first few times you scan through, just keep on searching and you will come across transmissions eventually! Once you do, you can start adding them to your memory channels and building up your own database of frequencies in your area.

NA-771 SMA-Female Dual Band UV 144/430Mhz 10W High-gain Antenna For Baofeng BF-UV5R

Type : NA-771
Connector : SMA Female Connector
Frequency : 144 / 430MHz
Gain : 2.15db(144MHz) / 3.0db(430MHz)
Max power : 10 Watts
V.S.W.R : Less 1.5
Impedance : 50 OHM
Color : Black
Length : About 400mm
Weight : 29g
Package weight : 37g
This antenna is also compatible with the following radios.
BAOFENG: UV5R/Plus, UV5RA/Plus, UV5RE/Plus, UV5RB, UV5RC, UV5RD, UV3RPlus, BF-320, BF-480, BF-490, BF-520, BF-V6, BF-V8 etc…
WOUXUN: KG-UVD1P, KG-816, KG-818, KG-819, KG-869, KG-889, KG-833, KG-659/E, KG-699, KG-669, KG-669plus, KG-689, KG-679, KG-659, KG-689plus etc…
LINTON: LT-2288, LT-3288, LT-5288, LT-3188, LT-2188, LT-3260, LT-2268, LT-3268 etc…
PUXING: PX-777, PX-666, PX-3288, PX-555, PX-666, PX-888, PX-6288 etc…
QUANSHENG: TG-K4AT, TG-2AT, TG-45AT, TG-42AT, TG-22AT, TG-25A
WEIERWEI: VEV-3288S ,VEV-3288 V-1000 etc…
FEIDAXIN: FD-6288, FD-268, FD-288, FD-150A, FD450A, FD160A, FD450A, FD-460A etc…
TYT: TH-UV3 etc…

 

Low profile SMA-Female Dual Band Antenna for BaoFeng 888s UV-5R

A low profile antenna that is great for vehicle communications that works better on UHF 400-520Mhz than VHF 136-174Mhz.

Specification:
 Max. Power :10W
Impedance:50ohms
Magnet diameter: approx. 30mm
Connector:SMA-Female
Length: 3 meters
Antenna height: approx. 140mm
Frequency: 136-174MHz 400-520MHz
Gain: 3.0 dB
Weight: 46g
This antenna is also compatible with the following radios.
BAOFENG: UV5R/Plus, UV5RA/Plus, UV5RE/Plus, UV5RB, UV5RC, UV5RD, UV3RPlus, BF-320, BF-480, BF-490, BF-520, BF-V6, BF-V8 etc…
WOUXUN: KG-UVD1P, KG-816, KG-818, KG-819, KG-869, KG-889, KG-833, KG-659/E, KG-699, KG-669, KG-669plus, KG-689, KG-679, KG-659, KG-689plus etc…
LINTON: LT-2288, LT-3288, LT-5288, LT-3188, LT-2188, LT-3260, LT-2268, LT-3268 etc…
PUXING: PX-777, PX-666, PX-3288, PX-555, PX-666, PX-888, PX-6288 etc…
QUANSHENG: TG-K4AT, TG-2AT, TG-45AT, TG-42AT, TG-22AT, TG-25A
WEIERWEI: VEV-3288S ,VEV-3288 V-1000 etc…
FEIDAXIN: FD-6288, FD-268, FD-288, FD-150A, FD450A, FD160A, FD450A, FD-460A etc…
TYT: TH-UV3 etc…

NAGOYA UT-106 10w Antenna for BAOFENG UV5R / UV5RA / UV5RE HIYG

This great little vehicle mounted antenna will provide extra coverage when out and about.

Specifications:
Length: Approx. 43cm/16.9″
Diameter: Approx. 3cm/1.18″
Frequency range: 136-174 400-520 (MHz)
Impedance: 50 (Ω)
Gain: 2.15 (dB)
Max power: 10W
Applicable models: Baofeng all models
Center frequency: 144 / 430MHZ
Weight: 60g
This antenna is also compatible with the following radios.
BAOFENG: UV5R/Plus, UV5RA/Plus, UV5RE/Plus, UV5RB, UV5RC, UV5RD, UV3RPlus, BF-320, BF-480, BF-490, BF-520, BF-V6, BF-V8 etc…
WOUXUN: KG-UVD1P, KG-816, KG-818, KG-819, KG-869, KG-889, KG-833, KG-659/E, KG-699, KG-669, KG-669plus, KG-689, KG-679, KG-659, KG-689plus etc…
LINTON: LT-2288, LT-3288, LT-5288, LT-3188, LT-2188, LT-3260, LT-2268, LT-3268 etc…
PUXING: PX-777, PX-666, PX-3288, PX-555, PX-666, PX-888, PX-6288 etc…
QUANSHENG: TG-K4AT, TG-2AT, TG-45AT, TG-42AT, TG-22AT, TG-25A
WEIERWEI: VEV-3288S ,VEV-3288 V-1000 etc…
FEIDAXIN: FD-6288, FD-268, FD-288, FD-150A, FD450A, FD160A, FD450A, FD-460A etc…
TYT: TH-UV3 etc…

BAOFENG UV-5R review

The radio snob in me wants to start off by saying that there are other radios out there – and many of them are a lot more reliable than the Baofeng UV-5R. Icom, Motorola,  & Yaesu make excellent HT (Handy Talkie) radios. And you might be much better served by having a more substantially reliable radio like one of those. If I had to put my life on the line I would prefer to have a radio I know I can count on to work when I need it to.

But as these are so inexpensive, and easy to get (on BANGGOOD) and since you’re usually looking at around $150 to get one of the better brands I decided to write this article to discuss the entry-level Baofeng so folks can understand what this radio can and can’t do. And since we now own 2 of them we shouldn’t talk too much smack about them now, should we.

The Baofeng uv5r review & Guide

Lets set your expectations. This is not a top-of-the line radio. Its not supposed to be. Its cheap, so you can rest assured that problems with these radios can arise from time to time. We’ve had one that cannot receive or transmit if the channel is changed unless you turn the unit on/off.

Versions

There are several known variants of this radio. All of them are the same hardware, the only difference is the firmware (software) they ship with. If you buy on Amazon you are probably getting the latest firmware, but there’s no guarantee. Its not a game changer, they all pretty much run the same from what I can tell.

Durability

Don’t drop these. They aren’t cream-puffs but they are not meant to be roughed up like some other radios are. But the build feels solid enough for what its meant to do.

Expendabilty

Our suggestion is to get a good HT from Icom or Yaesu if you can spring the +$150, and get a few Baofengs as beaters and backups. Strength in numbers. But if you want something today buy the Baofeng and you rest easy that at least you covered it.

Programming

Not horrible, but only if done on a computer. If all you care about is 4-5 frequencies then you can do it on the unit. You need the computer program CHIRP to program the HT. You also need a special USB cable. Avoid the cheap knockoffs. Been there done that.

You can download a greatly improved version of the Owners Operating Manual here. Its a good idea to save a copy of this to your emergency USB stick with all your other emergency documents. You DO have an emergency USB drive, don’t you?

 

Citizen Band radio

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:

  • high frequency (HF) band – (26.965 – 27.405 MHz)
  • ultra high frequency (UHF) band – (476.4125 – 477.4125 MHz)

The service is for public access and available to everyone. If a company chooses to use the service for business, they have no rights of exclusivity and must accept other users on the same channel.

Do I need a licence?

No. The operation of CB radios is authorised under the Radiocommunications (Citizen Band Radio Stations) Class Licence 2002. Class licences do not have to be applied for and no licence fees are payable.

The CBRS class licence does not authorise the operation of 27 MHz marine equipment.

What channel do I use to contact other travellers?

There are specific calling channels in the CB bands.

HF band:

  • channel 11 (AM – 27.085 MHz)
  • channel 16 (SSB – 27.155 MHz)

UHF band:

  • channel 11 (476.675 MHz)

Once you have established contact with another traveller, switch to another channel to continue talking. This frees the call channels for other users. If travelling in a convoy of vehicles, select a usual ‘working’ channel prior to setting out.

Can I use my CB radio to transmit data?

Yes. Data can only be transmitted on UHF channels:

  • 22 (476.950 MHz)
  • 23 (476.975 MHz)

Transmission must comply with the restrictions imposed in the CBRS class licence. These channels are dedicated to data purposes and should not be used for voice communication.

In an emergency

There are specific emergency channels that you can use:

  • channel 9 (27.065 MHz) in the HF band
  • channel 5/35 (476.525/477.275 MHz) in the UHF band

These channels are emergency channels and non-urgent traffic must be confined to other channels.

Organisations voluntarily monitor the emergency channels and may assist you in contacting the appropriate service in an emergency.

Conditions of operation

CB operators do not have to be licensed to operate their equipment, but the CBRS class licence imposes a number of operating conditions:

Compliance with mandatory standardsDevices operating under the CBRS class licence must comply with the relevant mandatory standards specified in the licence.

Operating frequenciesCB radios must only be operated on the channels that are detailed in the CBRS class licence. Operation on a channel that is not specified in the class licence is a breach of the licence conditions.

Proper conductThere are specific conditions regarding personal conduct during operation of a CB radio station, and penalties apply for improper conduct. In particular, the CBRS class licence states that:

A person must not operate a CB station:

  • in a way that would be likely to cause a reasonable person, justifiably in all the circumstances, to be seriously alarmed or seriously affronted; or
  • for the purpose of harassing a person.

Transmitter power levels

CB radio equipment must not exceed the maximum output power specified in the class licence. Attaching any external device, such as linear amplifiers, increase power is not allowed.

Other conditions

The operation of a CB radio is also subject to the provisions of the Radiocommunications Act 1992.

Breaches of licence conditions

CB radio users must comply with conditions in the class licence. If any condition of the licence is breached the operator will be liable for prosecution.

What if I cause interference?

Interference to television and radio receivers and other electronic equipment may occur when a CB radio transmitter is used nearby. Such interference is unlikely when mobile, but may occur in campsites, caravan parks or home base situations. Users should cooperate with the affected person and take reasonable steps to fix the problem.

Selective calling

Selective calling (selcall)-a technique used to enable the reception of calls from particular CB radios without having to listen to other users-is permitted under the class licence. Selcall uses the transmission of audio tones that are recognisable to receivers fitted with a compatible decoder. It can be used on either HF or UHF CB radios. Some CB radios come fitted with a selcall facility using continuous tone coded squelch system (CTCSS) techniques. CTCSS is only authorised on UHF CB bands.

CBRS repeaters

A repeater is a station established at a fixed location that receives radio signals from one CB station and automatically retransmits the signal to another station using the corresponding output channel. UHF CBRS repeaters can be found in all states and enable the range of vehicle to vehicle communications to be significantly increased.

CB repeaters are not authorised under the CBRS class licence. The repeater stations are usually located at hilltop radiocommunication sites and require specific frequency assignments and the issue of an individual apparatus licence.

Repeater channels

Channels 1 to 8 and 41 to 48 are designated as repeater output channels, with channels 31 to 38 and 71 to 78 the corresponding designated repeater input channels.

A repeater that transmits on channel 1 will always receive on channel 31. When operated in duplex/repeater mode the CB radio automatically selects the corresponding transmit/receive frequencies.

These designated repeater channels may be used for single frequency communications provided they are not used in the locality of repeaters.

Channels 5 and 35 are dedicated for emergency communications.

Please note: this document is intended as a guide only and should not be relied on as legal advice or regarded as a substitute for legal advice in individual cases.

Original Article

UNDERSTANDING UHF CB RADIO – WHICH CHANNELS SHOULD YOU USE?

What is UHF?

Simply put, UHF CB or citizen band radio is a two-way radio system that uses the 476.4250–477.4125MHz, radio spectrum for short-distance communications.
It is divided into 80 channels for various uses. The service is for public access and available to everyone but not all channels can be used by anyone for just any reason – there are significant penalties for misuse of channels.

For example, the Australian Government has legislated that channels 5 & 35 on the UHF CB Band are reserved for emergency use only 

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

LEGALLY RESTRICTED CHANNELS

The following channels are legislated as a part of the ACMA UHF CB Class Licence.

  • Channel 5 and 35 are the designated emergency channels, and are not to be used except in an emergency. To make an emergency call, switch your radio to Channel 5 with duplex on, if there is no response, try again with duplex off.
  • Channel 11 is the ‘call channel’ and is only to be used for initiating calls with another person, you should quickly organise another vacant channel to continue your discussion on.
  • Channel 22 and 23 are only to be used for telemetry and telecommand, packet data and voice transmission are not allowed.
  • Channel 61, 62 and 63 are reserved for future allocation and transmission on these channels is not allowed.

 

UHF’s distinct advantage over mobile phones is that it can work anywhere and requires little to no infrastructure to be in place. At the user end, all that is required is a basic radio set. The key disadvantage is that it operates on a line-of-sight basis, and therefore has very short reach. Under normal conditions, you can expect a good signal over a distance of 5 to 8km; in a high position (such as a hill), this can be increased to up to 25km. The upside is that you’re always communicating with those who are in your immediate vicinity.

UHF channels

Each of the 80 UHF channels has the following accepted use:

  • Channels 1–8 and 41–48: duplex channels (output).
  • Channels 31–38 and 71–78: duplex channels (input).
  • Channels 5 and 35: duplex channels strictly used for emergency communications.
  • Channels 9, 12 -17, 19–21 24–28, 30, 39, 49-60, 64-70, 79 and 80:general chat channels, simplex use.
  • Channel 10: 4WD Clubs or Convoys and National Parks.
  • Channel 11: Call Channel used for locating friends – a general meeting point for when communications are lost or beginning, before moving to another channel.
  • Channel 18:Caravanners and Campers Convoy Channel.
  • Channel 40: Australia Wide road safety channel used primarily by truckies and oversized load pilot vehicles.
  • Channels 22 and 23 (25kHz):Telemetry & Telecommand used for automated data communications only.
  • Channel 29: Road safety channel Pacific Hwy, Pacific Mwy (NSW & QLD).
  • Channels 61–63: reserved for future use

What is Duplex?

The ‘duplex’ function of the UHF system helps increase the range of UHF radios using repeater stations set in ideal locations, such as hills. In duplex mode, the fixed position station forwards the signal it receives from repeater input stations 31-38/71-78 to the corresponding output stations 1-8/41-48.

Any transmissions sent on non-duplex channels are sent in simplex mode, or directly between radio sets without the use of a repeater.

Changes from 12.5kHz vs. 25kHz band spacing

In 2011 the channel bandwidth or frequency spacing was split in two from 25kHz to 12.5kHz. This effectively doubled the number of available channels from 40 to the current 80. While most older radio units are not compatible, it is still possible to use them until the end of the 5-year transition period (2016).

Etiquette

It is important to remember that channels 5 and 35are strictly for emergency communications, as emergency services monitor channel 5 for requests for help. People found to be misusing these or any other designated channels can face hefty fines.

Once communication is established, it’s accepted that both parties continue on another channel to free the channel up. If they’re taking place over a short distance, these ‘one on one’ conversations can continue on any of the general-use channels.

It’s important to understand that all communications on every channel are public. Anyone within range of you or a repeater that you’re using can hear you and join in. For the most part, users are well behaved and respect the rules, but you may encounter trolls who want to cause trouble or new users who are unaware of the etiquette.

UHF radio is a great way of staying in touch with your convoy or just to see who’s about. Most importantly, it is a vital link to the outside world when things go wrong.