Observations of the codec
used for D-Star - How does the codec used for D-Star respond if
subjected to sounds other than those of the human voice? We
decided
to find out.
D-Star repeater
installation - Experiences, problems encountered with the
installation of a D-Star Stack at a very busy radio site - and
solutions to these problems.
The following are FAQ's provided by the Utah VHF
society.
Note that these may topically overlap the links above:
http://www.hamradio-dv.org/icom/DstarRptMods_NU5D.pdf
- "Discriminator audio" and "RSSI" modifications: If you
plan to put up a repeater, it is strongly recommended
that you read this page and make the suggested modifications. If
you need to do any RF troubleshooting on the repeater -
such as determine sensitivity, find out if there is enterference, or
even just make sure things are working properly - it is recommended
that you check this page out!
http://home.roadrunner.com/~mdmiller7/images/dv/ch_sp/Dstar_Co.pdf
- Measurements of co-channel interference: Mark, N5RFX, has
conducted Adjacent/Co-Channel
testing similar to those done by the Utah VHF Society mentioned
above: Note that the equipment used, methodology, and the
thresholds
for various aspects of these tests are slightly different from those
described on the Utah VHF Society page above, yielding slightly
different
results: The reader must take these differences into
account before attempting to draw direct comparisons between these two
sets of results.
A
Look Inside D-Star Modulation - An article (in .PDF) from the
Winter,
2009 CQ VHF Magazine about D-Star by Bob Witte, K0NR.
A Discussion
about Michigan Repeaters and D-Star - This article discusses
the co-habitation of D-Star and analog repeaters, D-Star channel
spacing, and a few other practical implications of the integration of
D-Star repeaters on the 2-meter band.
Radio
problems during a fatal fire. This page contains a
sobering example of a tragedy that can, in part, be attributed to
shortcomings of the communications system may be found here and
includes audio files and some brief analysis of what happened. Linked from Daryl Jones' blog.As with any blog, please use your judgment to weigh
possible bias of the author and its effects of the facts.
Please note that some of the problems associated with digital,
trunked systems do not necessarily apply to amateur radio
implementations of digital voice technology. It is, however,
well-worth the time for a designer of a radio network - amateur or
professional - to become familiar with these systems and take advantage
of lessons learned by others, applying them to system design, and to
the
training of those who are destined to use it!
The above lists are, by no means,
exhaustive: Other information may be found via web searches.
Questions, updates, or comments pertaining to this web page may
be
directed to the frequency
coordinator.