Frequently Asked Questions

Contact us for friendly, expert advice.

020 7183 4391

Many people are concerned about the safety of using cellular phones and portable radios , Motorola as a world leader in radio manufacture has commissioned many surveys and studies by public safety organisations around the globe. The results say that there is nothing to worry about.

If you are hiring then the radios will be pre-programmed with our supplier frequencies, the use of which is included within the hire charge. Alternatively if you have your own licenced frequencies we can program our hire fleet units to be compatible with any existing radios you have.

If you are purchasing radios then you must have a licence. If you do not currently have one we can assist you with your application for a fequency. You can obtain a licence application form together with all the information you need about licencing from the Ofcom website or contact us


The Ingress Protection rating grades the resistance and degree of protection from outside materials, such as water and dust, as classified by the International Electrotechnical Commission (IEC). The rating is split into two categories, Solid Particle Protection and Liquid Ingress Protection giving each product a two-digit IP rating e.g. IP54, IP55, IP56, IP66, IP57, IP67, IP68. It is the last digit which specifies the IP liquid ingress protection specification whereas the first number specifies the radios ability to stop the ingress of dust and fine particles. The higher the IP number the more waterproof and dust proof the radio is.

If you are looking for a robust radio you might think that you’re best to go for the highest IP available however please bear in mind that as radio handsets become more and more waterproof that their mechanical and electrical serviceability often becomes less easily undertaken and often more expensive to repair, due mostly to the design and sealing technology used in high waterproof IP rated radio handsets.

a. Whip antenna UHF 16 cm long High efficiency
b. Helical antenna UHF 9cm long Medium efficiency
c. Helical antenna UHF Stubby Low efficiency
d. Helical antenna VHF 14cm long High efficiency
e. Helical antenna VHF 9cm long Medium efficiency
f. Helical antenna VHF Stubby Low efficiency


UHF band radios are normally supplied with whip antennas this is the most efficient type.

VHF band radios are normally supplied with helical antennas as these are more user friendly (a VHF whip antenna would be approx. 400 mm long).

It is important to order the best antenna for your requirements, for short range on-site work a short helical or stubby will be ideal, but for long range it is better to use a long helical or a whip antenna.

Euro446 licence free radios have fixed antennas and must not be changed.

If you have difficulty deciding which antenna you need or would like more information please contact us

Things that have a bad effect on range:

Obstacles such as buildings, trees, hills, heavy rain, tunnels, low battery etc.

Things that have a good effect on range:

A clear path between radios, height above obstacles, fully charged battery etc.

Other factors affecting range:

Range can be doubled by using a base repeater station, placed in the centre of the required service area. Range can be seriously affected by using the wrong antenna on the radio, see our information section on antennas to enable you to select the best antenna for your radio.

Local base station

A local base station is basically a fixed desk-top radio. The benefit of having this type of radio is that it prevents someone from picking the radio up and walking off with it either intentionally or accidentally i.e. if you want a radio to remain at the reception desk in your building, or any other area you feel it is crucial to have radio contact, then a fixed desk-top radio may be a good idea.

Having a local base station will not significantly increase the coverage area of your two-way radio fleet. Although the fixed radio itself has a higher power output than a hand portable radio, the hand portable still needs to transmit back to the fixed radio, the range will always be dictated by the unit with the lowest power output, i.e. the hand portable. The antenna supplied with the local base station is typically sited in an elevated position, e.g. on top of a Portakabin, which may improve the range of hand portables connecting with it as they may have an improved sight line, however it will not increase the range between hand portables.

Repeater base station

A repeater base station is a technical product that can be installed on site, in conjunction with an antenna, to increase the coverage area. When a radio sends a message, the repeater receives the transmission and then repeats the transmission back out (on another frequency) to all other radios within the coverage area.

A repeater base station must be set up in a dry waterproof area that has a 240v power source. Locating the repeater and the antenna in the correct position to ensure that maximum coverage is achieved generally requires a site survey.

Repeaters are often set up with complex antenna systems as long-term solutions to help achieve coverage throughout a building or campus. Utilising Internet connectivity they can also be used to link multiple sites.

For customers requiring increased coverage at a temporary event location, repeater base stations can be set up with a simple antenna to improve coverage. If you are organising an event that covers a wide area and you think you may need a repeater contact us for advice and assistance.

It is important to note that a repeater increases the coverage on only one channel in analogue mode or two channels in digital mode.

This is a simplistic overview; if you think that you require a local or repeater base station please contact us and we will be happy to advise you.

Motorola batteries:

  • Lithium Ion (Lilon)
  • Nickel Metal Hydride (NiMH)
  • Nickel Cadmium (NiCd)

In order to ensure that these battery types, each based upon a different chemical technology, are correctly and safely charged and function properly, the Professional Series batteries contain a small Integrated Circuit that identifies its key parameters to the radio and to the charger.

Lithium Ion (Lilon)

These batteries utilise the most modern chemistry and provide the highest power at the lowest weight and contain a built in protection circuit. However, these batteries are not recommended for use at the extremes of temperature due to a marked increase in capacity.

For safety reasons these batteries must be charged in a ‘smart’ charger designed for the specific cell characteristics. All Motorola Professional , Compact and Commercial Series radios are suitable for the Lilon batteries.


  • Lightest weight of all batteries
  • State of the art chemistry
  • No memory effect
  • Highest potential number of charge discharge cycles


  • Longer charge times

Nickel-Metal Hydride (NiMH)

More recent technology which operates similar to and provides the same capacity as Nickel Cadmium batteries in a low weight package.


  • Lighter weight than comparable Nickel Cadmium batteries
  • Less prone to the memory effect than Nickel Cadmium
  • Fewer toxic metals used – environmentally friendly


  • Self discharges at approximately 30% per month when stored. Nickel Metal Hydride will not operate at as low temperatures as Nickel Cadmium.

Nickel Cadmium (NiCd)

This well proven chemistry provides the best performance at extreme temperatures but suffers from memory effect and provides the lowest power to weight ratio.


  • High number of charge discharge cycles
  • Good performance at low temperatures
  • Easy to recharge after prolonged storage
  • Capable of sustained high rate of charge and discharge


  • Memory effect will develop if battery is not fully discharged at each cycle
  • Battery does not perform well if it is left sitting in the charger and is only used for brief periods of time
  • Must be recycled by manufacturer safely since Cadmium is toxic.

Selecting the Right Battery

The selection of the correct battery for a particular application will depend on many factors. A typical procedure for battery selection is shown below:

  • Identify how many hours of operation are required
  • Identify if the product will be operated in an intrinsic safe environment
  • Identify the required operating temperature range. For example, inside all day in an air conditioned office, inside a food freezing plant, work in a coal mine
  • Having chosen the required performance, select the most appropriate radio battery combination
  • For most effective radio performance use only genuine manufacturer branded batteries

Battery Chargers

Rapid, tri-chemistry battery chargers have been developed with a distinctive new appearance in single and six unit versions. These “intelligent” chargers are able to detect the battery type and the amount of charge left in the battery which ensures batteries are charged for exactly the right time.

Additional charging indications provide meaningful information about the status of the charging. In order to minimise the costs of changing to the new professional series radios, there is a replacement single unit “charger pocket” available to upgrade existing GP900 and GP300 chargers that use the listed power supply units:

Part Number Description Connector
Single unit charger complete with power supply:
MDHTN3001A 230V Single Unit Charger Euro plug
MDHTN3002A 230V Single Unit Charger UK plug
Single unit charger for use with existing Transformer:
MDHTN9000A Single Unit charger pocket only
Note: This charger can only be used with the following GP300/GP900 Transformers:
2580611V02 230V Transformer Euro plug
2580611V03 230V Transformer UK plug
6 Unit charger without Power supply:
MDHTN3004A Multi-Unit Charger Euro linecord
MDHTN3005A Multi-Unit Charger UK line cord
Transformers for use with 6 Unit Charger:
2504548TO7 230V Transformer Euro plug
2504548TO6 230V Transformer UK plug
Wall Mount Kit :
NLN7967A Wall Mount Kit for Multi-Unit Charger


  • One tri-chemistry charger can be used for every battery in the product range, a Cost effective solution
  • Rapid charging times allow more batteries to be charged during a work-shift.
  • Easy to use – batteries cannot be inadvertently put into the “wrong” charger
  • Easy to use – indications provide useful information.

Motorola GP340 Battery Specifications

Battery Weight
Standard High Capacity NiMH Battery 202 gms
Ultra high capacity NiMH Battery 275 gms
High Capacity NiCd battery 225 gms
High capacity LiIon battery 125 gms
Average battery life @ 5/5/90 % Cycle Low Power High Power
With Standard high capacity NiMH battery 11 hours 8 hours
With Ultra high capacity NiMH battery 14 hours 11 hours
With NiCd battery 12 hours 9 hours
With LiIon battery 11 hours 8 hours
Part Number Description
HNN9008 High capacity NiMH
HNN9009 Ultra High capacity NiMH
HNN9010 Ultra High capacity FM approved NiMH
HNN9011 High capacity FM approved NiCd
HNN9012 High capacity NiCd
HNN9013 High capacity LiIon
















Memory Effect

Continually not fully discharging a battery causes an accumulation of very tiny gas bubbles and the formation of irregular shaped crystals which adhere to the cell plates.

These irregular shaped crystals drain the battery of its true capacity capability. The result is the battery will only charge to the level at which it was last discharged. For example, a person over many months routinely uses 70% of the battery capacity.

In a Nickel Cadmium battery that originally had a run time of 8 hours the run time could be reduced to only 5.6 hours after memory effect had set in. To avoid the memory effect, use all of the available battery capacity completely.

Note: Nickel Metal Hydride batteries are less prone to memory effect and Lithium Ion batteries do not exhibit this effect at all

The DMR (digital mobile radio) standard has been adopted by manufacturers all over the world so that their products can be integrated into sophisticated solutions for your communication needs.

There are three tiers to the DMR standard:

  • Tier I products operate in the 446MHz band and do not require a licence
    and are ideal for consumer or small commercial operations.
  • Tier II operates from 66-960 MHz and is used for conventional radio
    systems where spectral efficiency is required, and facilitates advanced
    voice features and integrated IP data services.
  • Tier III covers trunking operation in frequencies from 66-960 MHz.
    This is ideal for those organsiations who need to handle voice and
    short messaging as well as packet date services including IPv4 and IPv6.

TETRA (Terrestrial Trunked Radio) is the most robust technology for commercial radio systems having been developed specifically for government agencies and the emergency services i.e. mission critical communications.

In conventional systems a separate channel is allocated to each user group (e.g. cleaning, security etc.) and users have to manually switch frequency to change groups. The disadvantage of this is that while one channel is busy and has radio users waiting another may be unused. TETRA overcomes this issue by automatically allocating channels. This is obviously a major advantage for users with a large number of users.

The success and market uptake of TETRA in a wide range of sectors outside its original target has attracted many manufacturers and suppliers of products and services creating healthy competition and making TETRA more price competitive and economically viable for an increasing range of applications.

 TETRA has much to recommend it:

Technology developed for the most challenging mission critical applications

TETRA, which was the first digital radio technology, has been proven in some of the most challenging applications in the world offering scale, security and high-quality communications.


TETRA supports terminal registration, authentication and encryption.


TETRA can communicate in direct-mode operation (DMO) or trunked-mode operation (TMO). In direct mode operation (DMO) radios can maintain communication when the network is not available, i.e. when two radio users are out of range they can still talk to each other. When connected to the network radios in DMO can act as a relay for other radios that are out of range.

Fast data advanced apps

TETRA radios can process data applications while simultaneously receiving or sending voice calls, making better use of the spectrum.

Specially designed apps can

  • Combine a geographical information system, voice recording and radio dispatch
  • Issue visual alerts, swiftly delivering images to TETRA radios and Java-enabled devices
  • Access to multiple databases


TETRA uses a lower frequency than alternatives, which gives longer range, increasing coverage and reducing the number of transmitters required, thus cutting infrastructure costs.

 Full duplex calling

TETRA enables users to talk exactly as they would on a mobile device with both parties able to speak simultaneously.


Single site, multiple site or regional networks are all possible. A TETRA fully trunked multi-site system can accommodate over 100 radio users, equivalent to a DMR Tier III fully trunked multi-site system.

 Open-standard technology

TETRA is an open-standard, multi-vendor technology so you can mix and match products from different suppliers and create a system to suit your needs. The success of TETRA has created a strong base of application developers who are able to provide a wide variety of applications for use with TETRA.

Easy to licence

Currently obtaining a TETRA licence is a straightforward process and pricing is comparable to analogue and digital licences, which are sometimes difficult to obtain, especially in London.

In addition to the above TETRA shares key features of DMR alternatives, including remote network management, roaming between sites, repeater data interface and dispatcher software.

There are also some considerations in choosing TETRA:


TETRA is not compatible with analogue or other DMR systems. Uptake of TETRA requires investment in a completely new system.


The range of TETRA radios operating in peer to peer (DMO) mode is less than that of DMR or analogue.

The best radio systems are those that meet the organisation’s requirements, whilst it is important to anticipate likely future requirements adding unnecessary complexity or over specifying tends to only add to costs.

For more information about TETRA or to discuss your system requirements call us on 020 7183 4391

The Priority Interrupt feature on digital mobile radios is designed to allow an on-going radio call between two parties to be interrupted by a third if there is an urgent message to be communicated. The feature utilises the pseudo trunking , which allows a radio to receive signalling on two time slots. It reserves one time slot at any one time , keeping it free to send the Priority Interrupt signalling to all the radios on that channel when required. For example, if a call is in progress on Slot 1, the Priority Interrupt will be sent to Slot 2.

Radios that are configured to allow this signalling to be decoded will clear down any call they are currently part of. The radio that is transmitting will also be stopped and an alert given, the interrupting radio can then transmit as normal. Only radios that have Priority Interrupt encoding enabled can perform this function; this can be configured on a per channel basis in the radio configuration.

The Priority Interrupt can be sent either by a pre-defined button on the radio, a text message or by initiating an All Call. These options can be configured for each radio as required.

10 reasons why two-way radios are the right communication tool for industrial, construction and other heavy-duty environments.

Most of us wouldn’t be without our mobile phones but two-way radios offer distinct advantages for communication in heavy-duty environments.

  1. One to many. In addition to one-to-one calls, two-way radios can simultaneously transmit to a group of users. This is useful on a day-to-day basis, making staff aware of temporary hazards, situations needing attention etc, and may prove invaluable in an emergency. If a channel is busy Priority Interrupt enables key personnel to interrupt conversations if necessary.


  1. Health & safety features. Two-way radios systems can incorporate features such as Lone Worker, Man Down and Emergency Button, designed to summon assistance when a worker is in difficulty. When an alert is received the system indicates the location of the worker on screen (tablet or PC) and help can be quickly despatched.

A two-way radio system can also be designed to raise alerts when users enter controlled access areas.


  1. Design and build quality. Two-way radios are robust and durable, designed to work reliably in harsh environments. Choose a radio designed to meet the highest ingress protection standard, IP67, and it will be protected from dust ingress and the effects of immersion in water up to a depth of 1m for 30 minutes.

ATEX (intrinsically safe) certified radios are designed for use in combustible atmospheres (e.g. oil refineries) where most mobiles would be totally unsuitable. ATEX and standard radios are often designed with large PTT (Press To Talk), volume, channel and programmable buttons to make them easy to operate even when wearing gloves.

Should your radio get damaged or malfunction your dealer should be able to repair it. Parts are usually available for several years after a product has been discontinued for leading brands.


  1. Voice Clarity. For workers to do their job effectively and stay safe clear communication is imperative yet the working environment is often noisy, with ambient sound from machines, traffic, wind etc. The technology used in digital radios such as the Hytera X1p ensures excellent quality even in loud environments.


  1. Reliability. Two-way radios do not rely on the mobile network so even when this is compromised you can still communicate, which is one of the reasons why the emergency services use them.


  1. Coverage. With two-way radios you have control over the coverage and can design your system to accommodate areas where it is difficult to obtain a signal by the use of additional beacons.


  1. Integration. Two-way radio systems can be designed to receive alerts from building management systems (BMS), fire and intruder alarms, Supervisory Control and Data Acquisition (SCADA) from machinery etc.


  1. Visibility. Those monitoring a radio system can easily see which radio users are working and where they are. Where workers are alone, working irregular hours, working over a large area or working in a hazardous area this is a very real health and safety benefit both in terms of identifying a potential issue and despatching assistance from the nearest person.


  1. Accountability. Voice and text messages and staff movements can all be recorded by a two-way radio system if required.


  1. Focus. A two-way radio system can only be accessed with permission so if the only device a worker is carrying is a two-way radio then he or she is less likely to be distracted than if using a mobile phone with potential for internet access, private calls etc. From their point of view when they are off-duty they can turn their radio off and relax.


Nearly convinced? If you have questions about two-way radios and two-way radio systems call us for a no obligation chat on 020 7183 4391.

Convinced? Chatterbox offers all leading brands of professional two-way radios. You can buy radios or they can be supplied under a managed service contract, which makes budgeting easier. Call us for a quotation on 020 7183 4391.

Land mobile radio refers to communication systems, the most familiar of which being two-way radios (or ‘walkie-talkies’), used by people while on foot (hand portable two-way radios) as you would see used security guards etc., or in vehicles (mobile two-way radio), as you would see in taxis etc.

These type of radios that most people are familiar with are generally digital mobile radio (DMR) systems, which have often replaced original analogue systems. Both digital and analogue systems may be licensed or unlicensed.

There are two further main types of land mobile radio systems Terrestrial Trunked Radio (TETRA), which is a high specification system used by the emergency services etc and P25, which is its US equivalent.

Generally, LMR systems are deployed independently, but can also be connected to other stationary systems such as cellular networks or public telephone networks.

Not sure what you need or how much to spend?

Read our advice about buying the right licence free two-way radio for you.

10 things to consider before buying walkie-talkies (unlicensed two-way radios)

  1. Unlicensed or licensed?
  2. Reliability
  3. Build quality
  4. Coverage
  5. Size
  6. Durability
  7. Compliance
  8. Compatibility
  9. Battery life
  10. Support


  1. Do you need unlicensed or licensed?

Unless you need a two-way radio system that can be operated by multiple users over great distance, you do not need to buy a licensed two-way radio. If you think you may require licensed two-way radios please call us and we can advise you. Chatterbox sells licensed two-way radios and also offers short and long term rental.

FYI: 446 just refers to the fact that the radio is for use on unlicensed frequencies.

  1. Reliability

As we’ve said you get what you pay for so if reliability is very important then invest in professional quality radios. All our Hytera radios come with a two-year guarantee. In the unlikely event of something going wrong with them in that time it’s good to know you’re covered, and if you have any queries about using them then you can call us for support.

  1. Are the radios going to be used in testing conditions?

In this instance, look out for ‘IP’ within the specification list of the handsets. Ingress Protection classifies and rates the degree of protection provided against the intrusion of dust, water and even fingers. The two digit numerical code after the IP will tell you just how effective the handset is.

If you are looking for a radio that will be robust and resilient, we suggest the Hytera Pro Rugged (Hytera POWER446) , which has achieved Dust/Water Protection Class IP66, this means it’s dust tight and that “Water from heavy seas or water projected in powerful jets shall not enter the enclosure in harmful quantities”. Good to know!

4. What distance will you be using the radios over?

No radios however expensive will work where a physical obstacle obstructs the signal and it is important to be mindful of this, particularly for some applications e.g. skiing. Manufacturers can indicate a range but this will probably be the range that can be achieved under optimum conditions, i.e. over open flat ground, and as range is significantly reduced by obstacles in the path of transmission, achieving this maximum range will depend on your environment, i.e. in a high-density city environment or if a hill or large metal object is in the way, range may be dramatically reduced. Licence free radios are ideal for small-site, same-building and line of sight outdoor activities. If you need advice just call us.

  1. Are size and looks important?

If, for example, you are using the radio front of house in a hotel, restaurant or shop it might be important to have a discreet smaller radio. The Hytera Pro-entry (Hytera TC-320 446) is ideal if you’re after a light, more compact two-way radio.

  1. Are the people who will be using the radio not too gentle?

If you need a hardy light-weight two-way radio, the Pro-Standard Radio (Hytera TC446S) is ideal. Offering excellent battery life and enhanced voice quality, it is ideal for manufacturing, warehousing and distribution.

  1. Are you using the radios abroad?

All our Hytera radios, like all 446 unlicensed radios, can be used anywhere in the UK and mainland Europe. If you are travelling outside this area you will need to investigate which radios are suitable.

  1. Are you intending to use your Hytera radio with others you already own?

Our Hytera radios can be programmed to either analogue or digital so will work with most other two-way radios

  1. How long do you need the radios to work between charges?

If you need your two-way radios to last more than an average working day the Hytera Light Weight Pro Standard (Hytera TC446S) and the Hytera Pro Rugged (Hytera POWER446) both offer longer battery life power enabling you to transmit and receive, on a 5-5-90 basis, i.e. transmit (talk) 5% of the time, receive (listen) for 5% of the time and be on standby for 90% of the time, for around 24 hours. You can also buy additional batteries.

  1. Can you get support and advice if you need it from your walkie talkie retailer?

Your choice of radios and how much you spend depends entirely on what you are intending to use them for. If they are for your children to play with you’ll be fine with something from a toyshop but if you’re buying them for your business you need to invest in the right radios for the job. Basically, you get what you pay for. The two-way radios we supply are Hytera professional quality products, backed by a two-year guarantee.

Still confused or need advice? Call us on 01883 334792


Good to know: The main benefits of two-way radios


If your workforce currently communicates using mobile phones, you have no doubt experienced the pitfalls of a method reliant on a system that can crash for multiple reasons, ranging from bad weather to a fault with the actual network. Whatever the cause, there is usually not a thing you can do about it so you or your employees are left incommunicado. With a two-way radio system, the only loss of communication will be through (very occasional) battery failure and that can be rectified and addressed immediately. Airwaves never crash.


Two-way radios are an immediate, fuss free way to communicate with individuals or multiple groups of people. There is no dialling, waiting for an answer or getting an engaged tone. The recipient can immediately tell who is communicating with them, they learn the nature of the interaction and can respond instantly. And, because two-way systems are closed systems, your colleagues do not need to field unwanted calls from unauthorised contacts. Two-way radios are the communication industry’s answer to an invite only party.

Multiple channels

With a two-way radio you can choose a multi-channel system with one channel for each department within your company. That way if you wish to speak to a single staff member about a matter that only concerns their department, you will not disturb your entire workforce with matters that don’t concern them. As your organisation grows so too can the number of channels and handsets.

Group calling

You may be able to conference call using your mobile phones but this relies on everyone having their lines free at a specific time. With a two-way radio you can communicate with an entire group at the push of a button.


Because your workforce can be contacted instantly and everyone can hear what everyone else is doing, there is a level of intrinsic safety that comes from this. Leaving you, the employer satisfied that you are looking after the welfare of your staff and your workforce feeling confident that their well-being is of the utmost importance.

Cost effectiveness

No call charges, licence fee or training expenses, minimal running costs, and no facility for making personal calls.

For those who working in proximity to flammable gases, mists or vapours or combustible dusts safety should be a priority. In these types of situation, where explosions could cause loss of life and serious injuries, regular two-way radios are potentially hazardous and ATEX intrinsically safe mobile radios, which meet the requirements of the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996, must be used. Further information about ATEX and explosive atmospheres can be found at:

For information, ATEX two-way radios are conventionally blue to allow them to be easily distinguished from other radios to ensure that users bring only ATEX radios into potentially explosive environments.