Making radios talk to each other.
We are often asked to make different radios talk to one another. Sometimes this is possible and sometimes it is impossible. When it is possible we nearly always need the original radio to Read it’s data to make the new radio compatible because there are often many settings that have to be adjusted to make radios compatible.
This article gives an outline of what is required to make radios communicate. This article is only relevant for commercial licenced and licence-free radios. It is not relevant to HAM or amateur radio or military radio equipment, neither of which we deal with.
All radios are manufactured to comply with international and national licensing requirements. They are made to very specific standards. Broadly there are two types of radios legal to be used in the UK.
PMR 446 radios. These are licence free and can be used without applying for a licence. The can only be used on their factory set frequencies and are often used without anything other than their factory programming.
Licenced radios. These require an OFCOM licence to use. They have to be programmed to match the frequencies issued by Ofcom
NOTE: PMR446 radios can only talk to other PMR446 radios. Some licensed radios can be made to talk to PMR446 radios but this contravenes OFCOM licensing regulations and is an offence to make them do this.
The rest of this article refers only to Licenced radios
Licensed radios are very adaptable and different models from different manufacturers can often be made to talk to one another if certains settings can be made to match.
Commercial Licenced radios are available in one or more of the following frequency Bands.
UHF 400-470 MHz The most common band. Works best in urban environments
VHF 136-174 Mhz Works best in rural open country.
VHF Low Band 66-88Mhz. (uncommonly used)
NOTE: Radios are manufactured to work on one band only. They cannot be made to work on another band. A UHF radio can never be made to talk to a VHF radio and vice-versa.
NOTE: Two radios need to be in the same Frequency Band to communicate.
Same-band radios then need to be on the same Frequency to communicate. This is set at the time the radio is programmed and is always feasible.
Radios transmit in one of at least three modes. All radios need to use the same mode to communicate.
Analogue - Currently all radios have the capability to talk in analogue mode, even ‘Digital’ radios.
Digital DMR - This mode is very popular and available on some but not all radios..
Digital DPMR - This is used on some Kenwood and Icom radios.
Signalling is a way of making the radio’s speaker unmute. Radios need compatible Signalling to work. Usually if the Mode is compatible then signalling will also be compatible. The exact signalling settings have to be matched.
Some radios use an Encryption key. The Encryption key needs to be known and to match for radios to communicate. Encryption keys cannot be read from an existing radio.