Digital Mode Repeaters

Transcription

1 Digital Mode Repeaters CLAYTON W5PFG HOOD COUNTY AMATEUR RADIO CLUB JANUARY 7, 2019

2 Hood County Digital Mode Repeaters K1DRP D-STAR MHz W5HCT D-STAR NA5AA DMR, Linked to DMR-MARC and Brandmeister Networks (Color Code 1) Majority of digital mode repeaters are on UHF nationwide, with exception to some areas.

3 Common Repeater Digital Modes Unlike traditional analog FM repeaters, your voice along with some data is transmitted across the repeater and network. Two basic modulation schemes result in several different modes: C4FM DMR ETSI Standard Project 25 (APCO 25 Standard) NXDN Kenwood / Icom Yaesu System Fusion (YSF) GMSK D-STAR Japan Amateur Radio League (JARL) None of these modes are interoperable without some sort of Gateway If you tune to a digital mode repeater using an analog radio, you ll hear the digital noise but no voice!!!

4 What Data is Carried in the Signal? Data included in a Digital Mode system may include: One or two digital voice streams Callsign or other unique Identifier (DMR uses a numeric ID) Local Repeater Local Gateway Destination User or Network APRS/DPRS Location information

5 Prevailing Digital Modes for Amateur Use D-STAR The most established / longer in use, predominantly Icom but Kenwood entered market with TH-D74A handheld Digital Mobile Radio (DMR) Fastest growing, many equipment options Yaesu System Fusion (YSF) Newest, Yaesu only Each provide unique pro s and con s worthy of experimentation and use by amateur radio operators but the point of this presentation is not to debate which is best!

6 Linking to the Outside World All of the three most common Digital Modes for repeaters share a common element the ability to link outside your local repeater to a wider area D-STAR calls these Reflectors with a nomenclature like REF004B DMR calls these Talk Groups with a number like YSF calls these Rooms with a number and name A digital mode repeater can be used for local communications only but in many cases are linked to regional or interest-related groups

7 Linking to the Outside World Many of the groups are regional in nature, such as REF004B on D-STAR: Many Texas repeaters link here TG 3148 on DMR: Many Texas repeaters link here There are also interest-specific groups, such as TG on DMR: A place where AMSAT people gather You must know what linking capability your repeater offers. Not all repeaters can access all groups or regions. For example, DMR is predominantly split into two segments: DMR-MARC & Brandmeister, and without special bridges they can t cross-communicate

8 Digital Modes without a Repeater Hood County is serviced well by three repeaters, but you may sometimes want to link somewhere for an extender period or you may be out of range the repeaters and want access to the broader network. This is achieved by using a personal Hotspot. A hotspot is a small simplex repeater you can communicate with directly by your HT or mobile radio. The hotspot has a small, onboard transceiver and requires an internet connection to access the digital networks.

9 More About Hotspots Many of these are MMDVM s Multimode Digital Voice Modems Common models: OpenSpot or OpenSpot2 Higher end, but robust and easy to setup/use MMDVM HS Hats This is a small daughterboard ( hat ) that sits atop a Raspberry Pi computer Many makes and models of HS hats on the market Personally I detest Jumbo Spots these are stolen intellectual property from hams manufactured in China, some known to be fakes and inoperable Caveat Emptor! The ZumSpot is a very popular option offered at HRO Hotspots, aside from OpenSpots, are not necessarily plug and play and require some tinkering, but are very worthwhile so you have your own personal device to access DMR/D-STAR/YSF groups.

10 What do you need? Icom and Kenwood offer D-STAR radios varying in price $ Strong used market for Icom D-STAR handhelds and mobiles. I d not go any further back than an ID- 31/51 or ID-880, though for best audio quality. Kenwood TH-D74A is probably most advanced D-STAR HT available. TYT/Hytera, AnyTone, Connect Systems, and Motorola are just a couple of vendors offering DMR radios varying in price $ I would suggest avoiding Baofeng due to poor track record w/dmr Don t fall victim to the Motorola fanclub. You do not need a $ HT to work DMR. The growth of DMR can be attributed to the $80 TYT MD-380. Yaesu offers YSF-capable radios varying in price $ The FT-70DM is a fair choice for an HT, FTM-100 for a mobile.

11 What else do you need? Patience Digital mode use is not quite as intuitive as programming your radio for the repeater. Radio configuration file Also known as codeplug to the DMR world, this file essentially helps you get up and running quickly Active locals can help you here, if you say please Read HOWTO s and watch YouTube videos There are MANY excellent tutorials Register on the network Many digital modes, with exception of YSF, require you to register your callsign or ID to use the network outside of a local repeater

12 Common Myths Digital Modes require an Internet connection at home or repeater sites True for wider access beyond local repeaters False for standalone repeater use like majority of analog repeaters Digital Modes offer poorer coverage False at fringe range, it is widely accepted that digital modes have a competitive edge Digital Modes make everyone sound like a robot True some radios of older vintage may be less desirable to the ear Digital Modes enhance battery life of many HT portables True widely accepted that TDMA (DMR, for example) yield 40% improvement

13 Clayton s Picks for Entry Level If you don t want to spend a fortune yet want to experiment with the two modes available here in Hood County, I would recommend one of these options: D-STAR Used: Icom ID-31, sub $200 or ID-51, $250 New: Kenwood TH-D74A, $ DMR TYT/Hytera MD-380 (without GPS), $80-90 Used I ve seen as low as $40 shipped AnyTone AT-D868UV, $180 You may see why DMR is more popular but like anything, there are trade-offs.

14 Questions, Comments, Feedback to I m slow to respond.