Motorola MTP700

The Motorola MTP700 is a Tetra handheld which was introduced shortly after the millenium change on large scale by dutch emergeny services. Except Tetra became well know as the cornerstone of the notorious C2000 network, this protocol has also found its way into the commercial sector. ‘Entropia’ offers nationion wide Tetra coverage, but also some (large) companies have their own closed Tetra network.

From this private segment equipment starts to find its way to the second hand market. Which means it’s getting an interesting niche for radio amateurs. The difference between Tetra equipment from the commercial sector and the radios from the emergency services is hidden in the firmware. Emergency services are using TEA2 encryption. Possession by companies and private persons is prohibited and prosecutable!

Motorola MTP700 met 'stub' antenne
Motorola MTP700 with ‘stub’ antenna

Over the internet I could get hold of MTP700 radios with so called ‘clear’ firmware, so without TEA2 encryption. The portables had been programmed already into the 70 amateur radio band. But there were some traces of the original programming in the radio, which point to the former owner.

So then I was the proud owner of two of these radios, and after some research I’ve also got the original programming cable and corresponding software. And then? Then the big search on the internet started in the same pace as the huge puzzle what all functions and settings mean. More about this will follow on the ‘Projects’ blog pages. Important to know:

Programming mode: the radio won’t spontaniously communicate with the computer. It has to be kicked into programming mode manually. This can be done by pressing and keeping pressed the keys [1] and [9] (in that order, not quasi together), the switch on the radio. Release the keys after a few seconds, then the radio is into programming mode. The display won’t show anything and the MTP700 won’t react on anything. In case the radio won’t communicate properly with the computer although the settings in the CPS (like serial port) are correct, something went wrong while entering programming mode. In that case leave the programming mode and start over. Keep in mind to first press [1] and keep it pressed. Then press [9] and keep it pressed as well. And while both keys are being pressed, switch on the radio.

Leaving programming mode: can be done in two ways. In case the radio correctly communicates with the computer, the CPS shows a button with a vertical red line in a red circle. By clicking this the radio is switched off by the software. Afterwards the on/off switch can be turned to ‘off’. When switching on the radio again, it will boot as usual. In case the CPS refuses to communicate with the radio, the only way to leave programming mode is to turn the on/off switch to ‘off’ and remove the battery for a moment.

Programming HAM radio frequencies: on YouTube some movies can be found how Motorola Tetra radios are programmed out of band. Normally 430.0000 MHz is the highest possible frequency which can be entered. By in some cases the CPS (the ‘lab’ version) can be tricked to allow frequencies up to 440.0000 MHz. In these YouTube movies this trick is done with more recent Motorolas. How this has been done with the MTP700 is still unclear to me. Luckily enough it’s possible to read the codeplug (also the 70cm HAM frequencies), edit the programming and write it back to the radio again. Also cloning of an out of band codeplug to another radio is possible.

Disclaimer: please don’t ask questions about listening into communication of emergency services! 1. this is strictly forbidden; 2. these radios are technically unable to access the emergency network; 3. also using nicked radios won’t be able to access the emergency network as they’re banned from the system.