D-Star Information
To be updated shortly - 21/7/2009.
The Worthing D-Star Project - Progress Report, 20/1/2009
The 70cms NOV for the Worthing D-Star Repeater GB7JH, was issued to Kelvan M0KEL on the 25th November, some 4 months after the application was made. (The 2 metre application is still with the ETCC.) So we can now progress with getting the 70cms side on-air.
The callsign of the repeater GB7JH was chosen as a tribute to Jim Hicks G4XRU, SK, from whom a bequest to the Club, has partly financed the repeater.The Icom hardware (the RP-2C controller and the RP-4000V 70cms RF module), has now been delivered to the Club and has been checked out. The Gateway Server has been loaded with the Icom Gateway software and GB7JH has been registered with the Trust Server (K5TIT) in the USA, using a temporary connection to the Internet.
The eventual site of GB7JH in a Worthing Council building is being prepared. The antenna has been installed and an ADSL broadband connection has now been activated. The remaning tasks are to install shelving and mains power sockets. An announcement will be made when a firm date is known.
The allocated frequency for GB7JH B, (the "B" indicates the 70cms RF module), is as follows: Output (Tx) is 439.7125MHz, input (Rx) is 430.7125MHz, -9MHz offset.
Introduction to D-Star
What is D-Star?
D-Star is an acronym for Digital Smart Technologies for Amateur Radio. It is an open standard digital communications protocol established by JARL, (Japan Amateur Radio League). The fact that it is an Open Standard means that the protocol documents are freely available, and that anyone can use and/or implement D-Star without having to pay royalties
What can D-Star do?
The D-Star protocol allows suitably-equipped transceivers to communicate using a digital voice channel, (DV Mode), giving advantages of lower bandwidth and better readability, especially under conditions of marginal signal strength. The voice channel is always crisp and clear.
As well as digital voice, D-Star permits a 1200baud data channel, that normally is used for displaying the callsign of the person currently transmitting, but can also exchange short text messages concurrently with the voice channel. If the transceiver is fitted with the GPS satellite receiver, positional information can be sent as well, using the 2 metre, 70cms or 23cms bands.
Another feature of D-Star is the DD Mode (Digital Data). This allows high-speed (128kbit) data to be exchanged. However, this is only available for the 1.2GHz (23cms) links.
While it is possible to have simplex QSOs using D-Star, using D-Star Repeaters extends the range of contacts, in the same way as analogue repeaters. A repeater can also handle crossband contacts, and via Internet Linking, can extend the scope of contacts worldwide.
What does D-Star sound like?
Being a digital protocol using a fairly narrow bandwidth, (4.8kbps for the DV voice channel), it does give a certain "digitised" quality to the speech. Links to two examples, one for strong signals, and the other for weak signals, are available here.
| Strong Signal Example | Weak Signal Example |
How much is D-Star used?
In the UK, there are currently 11 Repeaters, and a further 3 on the UK Repeaters list. More are being planned.
There are over 100 D-Star users in the UK, and something like 500 users world wide. See the http://www.d-starusers.org/ website for up-to-date information.
Further Information
Further information may be obtained at the following websites:
UK D-Star wiki
D-StarUsers.org
Texas Interconnect Team
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The Worthing and District Amateur Radio Club is affiliated to the Radio Society of Great Britain. |
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Updated - 21/07/2009