Archives February 2014

handheld walkie talkie

Ensuring safeguarding when using radio communications in schools

Radio communications offers schools an essential safety tool, providing instant communication in emergency situations, and can be an important tool for safeguarding.

However many schools do not seem to offer their staff proper training in its use. I have heard a local primary school near me giving out detailed child descriptions, including name and location in the school grounds. This is a potential safeguarding issue.

They have been sold handheld radio equipment by a radio company, more concerned with their bottom line, than safeguarding compliance.

As a head teacher, you need to ask yourself, can others ‘eavesdrop’ on my school communications?

Many professional handheld radio solutions that schools use, are not secure communications, and can easily be listened to.  Are your communications secure?

There are also legal implications to be considered, apart from safeguarding, including the ‘Wireless & Telegraphy’ acts which apply to your staff.

We offer onsite training & equipment reviews to help your school.

(c) Craig Miles 2014-2023

    The Internet of Things (IOT)

    The ‘Internet of Things’ is a term that is due to become more widely known during 2014.

    One application of the Internet of Things, or IOT, is smart vending machines. For example the machine would know when it had run out of mars bars.

    It would the automatically send this data to a central database, which would automatically contact a delivery driver in the field. The driver could be instructed to change his delivery route, and go to replenish the mars bars in that empty vending machine.

    This is just a fraction of how machines will automatically communicate with other machines, and even with people (the delivery driver for instance).

    (c) Craig Miles 2014


      M2M (Machine-To-Machine Communications

      M2M (Machine-To-Machine) Communications

      M2M is short for ‘Machine to Machine’ communications. It works in a similar way to mobile phone communications (Human to Human).

      M2M transmits data in real-time between machines automatically, and without human intervention.

      Data can be transmitted both wirelessly and by fixed wired methods.

      Applications of these technologies include remote monitoring of water levels; smart road signs and remote machinery monitoring.

      Wireless technologies are generally the preferred method of transmitting machine data, due to the flexibility of equipment location. Wireless technologies include low powered terrestrial radio transmitters, satellites, and the mobile phone networks.

      (c) Craig Miles 2014

        CB Radio AM & SSB CB Radio legal in UK

        CB radio operation became popular in the UK in the late 1970s / early 80s. The early operators using imported AM, or Amplitude Modulation types, as well as SSB, from the United States.

        The use of AM & SSB (sideband) was illegal in the UK, but despite this thousands of people used it. The government decided to legalise CB radio use in the UK in 1981, however the legalised ‘CB 27/81’ standard used Frequency Modulation, or FM, rather than AM.

        This meant that the large user base of existing AM users were still operating illegally.

        AM CB operation in the UK largely died out, though SSB continued to be used illegally, due to the long distance communication that can be achieved. This is particularly true at the peak of the Sun Spot cycle, which peaks around every twelve years. Worldwide communication is possible, with suitable aerials, power and accessories.

        The UK government has recently announced that they intend to legalise AM & SSB operation to harmonise the UK with other European countries from summer 2014.

        Yesway Communications, can supply CB radios such as the ‘President Jackson’ model shown at the top of the page for £300, inc delivery to mainland UK (and subject to stock availability).

        President Jackson AM/ SSB CB

        So is CB radio any goood for business users in 2022?

        Well for starters CB is meant to be used for non business purposes only.

        That said, we have come across some farmers using it for communication.

        A particular farmer that came to us for radio communications advice, was using CB in his tractors, combine harvesters and 4×4 vehicles.

        He was getting a few miles coverage, though the coverage was variable, even between the same places, but on different days.

        This is due to propagation effects at the fairly low frequencies that CB uses.

        The antennas were also an issue, as they had high SWR (Standing Wave Ratio) readings. This meant that some of the transmit power being sent from the CB to the antenna, was being reflected back towards the radio.

        Whilst this is a bit off topic for this blog post, it is a reminder that equipment needs regular checks and maintenance.

        For this particular farmer our solution was initially VHF mobiles installed in the vehicles. 

        Later we added to the system, but adding a hill mounted VHF repeater, and handheld radios.

        The result was much better communication range for the farmer, and no channel interference.

        For business use, we therefore always recommend licenced professional UHF and VHF radio equipment, rather than SSB / AM / FM CB radio.

        The reason for this is that CB is not designed or licenced for business use in the UK.

        Nor is it particularly convenient, due to antenna length.

        CB radio operates in the 27MHz frequency band, which means that its ‘wavelength’ is around 11 metres.

        This results in the requirement for relatively long antennas, compared with licenced business radio.

        The higher the frequency, the shorter the wavelength, and the shorter the antenna.

        Having the antenna at the correct size affects radio performance, due to what is called ‘resonant frequency’.

        Having the antenna length matched to the radio transmit frequency, will maximise two-way-radio performance and range.

        A ‘resonant’ antenna, will also protect the two-way radi, from potential damage.

        The damage could occur, because the rf power being transmitted, won’t all be efficiently going from the antenna. Some will be reflected, back into the radio.

        Another consideration, is transmission range.

        With CB radio, you can get better performance than standard AM or FM, by using SSB (Single Sideband). 

        However long range transmission is not reliable, due to atmospheric conditions. These changes vary not only within the 11 year ‘sunspot’ cycle, but at different times of the day.

        Therefore business radio offers a more reliable solution.

        With business radio, you can increase coverage range, using ‘radio repeaters’.

        Radio repeaters re-broadcast the weak received signal, at a stronger signal level.

        By using radio repeaters which are connected together via Internet or microwave links, national (even international) coverage is possible.

        Another alternative, is to use PTT over cellular, which combines the instant communication benefit of traditional two-way radio, with the mobile (cell) phone network.

        PTT over cellular can therefore easily allow national or even worldwide communication.

        Of course voice communications aren’t the only forms of radio communications available. IOT, or the ‘Internet of Things’, allow monitoring of things such as agricultural and building conditions.