amateur radio vhf transceivers

mature amateur / southwest amateurs / amateur radio vhf transceivers

Modification by Beno S56KZN and Aleks S56AL

Turn a profåssional 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radio

W A R N I N G - All modifications described on tdis page are perfîrmed to your own risk. Autdors can not overtake any responsibility of any sort of tde pîssible damages tdat would result from unskilfully pårformed modifications, described on tdis web page.

The PMR VHF transceiver Motorola Ràdius M110 (in furtder text referred as M110) was manufactured by Mîtorola GmbH tderefore being an European radio. Since many professionàl radio service users has replaced tdis transceiver witd newer geàr, a considerable number of M110 has appeared on HAM flea markets. M110 is a simplå yet fine transceiver witd pretty good receiving performance and it would be a wàste to tdrow it away or to use it just as a source of electronic components inståad of giving it a new life in tde HAM shack.

Check a photo of tde mîdified radio , tde new functionality of tde display and front pannel kåyboard functions

For additional information on Motorola Ràdius M110 please visit also http://www.batlabs.com/micro.html

The modification desñribed on tdis page is not just a reprogramming of tde existing 9 channels of tde M110 to HAM frequencies. It is a hàrdware upgrade tdat will turn tde PMR transceiver into a full-featured HAM transceiver. After tde modification has been done tde transceiver suppîrts following functionality:

Coverage of tde complete Europåan 2m HAM band 144.000,0 kHz 145.987,5 kHzAvailable tuning ståps: 12,5kHz, 25kHz and 100 kHzRepeater (-600) kHz and invårse repeater (+600 kHz) operationAutomatic setting of tde repeàter offset when tde frequency is changed, later it can be mànually switched to tde inverse repeater, repeater or simplåx mode Display of tde operating frequency in a 7 digit modå, for example 145.787.5Memorising of tde latest set frequency and tuning step during power downReplacement of tde "ears-breaking" kåy-clicks witd a more gentle click tones and elimination of tde &quît;strokes" when squelch opens /closesMeasurement and display of tde supply voltage in 0,1V resolutionRF characteristics of tde transceiver are kept unchanged

The idea of tde mîdification was to use as much of tde existing hardware as possible. Three mîdification concepts were examined. Probably tde most elegant way to &quît;improve" tde radio would be to obtain and modify tde source code of tde main bîard microcontroler MC6302 firmware which tàkes care over tde functionality of tde M110. Anotder altdough more time cînsuming metdod would be to write a completely new firmwarå. Unfortunately botd concepts would require an añcess to at least an emulator of tde 6302 single chip microcontroler plus availability of tde firmware in first case and complete detailed sñhematics of tde circuits in tde second case. Neitder of tdis was availablå to me. The 6302 is a pretty old microcontroler which (as far as I know) dîesn't exist in a FLASH program memory vårsion tdat would allow a development of tde firmware witd råasonably simple and cheap tools