Saturday, 11 April 2015

Digital and other ramblings

Well, after much deliberation I have got hold of a DMR radio. I weighed up the options between DMR, System Fusion and DSTAR and plumped for the DMR - MARC system. DSTAR is great, well established and quite popular but the equipment is fairly expensive and the Yaesu system isn't yet proven and I hear varying reports as to its functionality. The radio I have I'd the Connect Systems CS700 UHF handheld. It is both digital and analogue and has an output of 1 or 4W.

The requirements for using the DMR MARC system include registering for a user ID which is transmitted with your QSO, giving your radio a unique identifier which can be checked against the DMR MARC database. It a a bit like a digital

The radio needs to be programmed using a data set called a codeplug which contains all the details the radio needs to access the network. My radio came pre programmed but I have had to adjust some settings for analogue repeaters but once programmed correctly the radio is quite impressive.

Digitally the audio is superb with no loss of signal quality but there is no degradation of signal as with FM - when the signal deteriorates to a level that the radio cannot receive then the entire signal drops out. As the network of repeaters increases there is a "roaming" option which will re tune you to the next strongest repeater on your route. Each repeater setting is known as a "zone" and in each zone there are "talkgroups". Talk groups are like individual channels and are available locally, nationally and worldwide, dependent on which talkgroup you are on so it doesn't matter which repeater you use, the talkgroups remain the same.

I have fitted a CTCSS board into my old Standard C5600 radio and now FM AV repeaters are now available to me again. The Icom IC-E208 now being installed in the car to maximise my 50W operating limit.

SKARS meeting this week (15th April) includes a presentation from M0OBL on the build of his Elecraft rig. Details on

73 de 2E0ENN

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