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DMR-ZA is located in South Africa and is part  of the DMR-MARC network, a worldwide network of dedicated digital  amateur radio repeaters located in over 37 countries with more than  11040 registered users, originally set up by a group of Motorola  engineers who are also active radio hams.

Now approaching more than 400 repeaters worldwide, each is able to provide local, regional and worldwide repeater coverage.

Repeaters  on the network are connected all the time (24/7). TRBO radios have  great voice quality, great coverage and extended battery life all in  LESS THAN A 1/3 of the channel bandwidth of a traditional analogue FM  repeater with TWICE as many voice channels! This offers you a reliable  and scalable choice in connectivity: local, regional, national and  international.

There's  much more than that though - the network allows two completely separate  QSO's at the same time, a unique feature made possible using Motorola's  "Time Division Multiple Access" (TDMA) technology. This enables a TDMA  repeater to divide transmissions into two discrete and pre-selectable  "talkgroups", routing them appropriately to others monitoring the same  group anywhere around the world. Effectively, this means two completely  separate voice channels are possible within one standard 12.5kHz  frequency allocation - highly efficient use of the spectrum!

Time-Division  Multiple-Access (TDMA) preserves the full channel width and divides it  into alternating time slots that can each carry an individual call.  Motorola maintains that two-slot 12.5 kHz TDMA-based systems, provides  6.25 kHz equivalency. This means that two seperate conversations can be  handled by the one repeater, on the same frequency but using two  different "channels".

TG1 is for Worldwide Calling and for QSO's less than 2 minutes. This is not a talkgroup to ragchew on!

TG13  Worldwide English is for English speakers. TG13 is available 24/7 on  many systems and here you can make international calls and there is no  time limit other than being courteous and not monopolizing the  talkgroup, allowing others to use it. (That's the advice of any wide  area talkgroup including TG3 North America). Remember, TG13 is not for  USA-USA or USA-Canada calls - TG3 North America is for that. If you want  to call the UK, Australia, New Zealand, South Africa, or English  speaking hams in other countries use TG13. PLEASE DO make international  English calls on TG13.

Make  our fellow overseas hams feel welcomed to join us. Let's key up on TG13  from time to time by announcing our call and asking for any  international traffic using plain language. (Don't call CQ CQ CQ - this  is not HF).
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