[Dstar] D-Star Simplex

[Dave Ingram]

Tony Langdon wrote:
> Emergency comms and infrastructure are not necessarily mutually
> exclusive.  It depends on what and where the emergency is.  Not all
> emergencies take our infrastructure (e.g. a chemical spill), and some
> emergencies are not local (I routinely deal with some on the other
> side of the world).  Those of us involved in emergency communications
> need to embrace these new modes and systems, get to learn them, and
> then add them to our existing tools, so we're able to come up with the
> best communication solution for a given situation.  Some situations
> will suit D-STAR, gateways and all, others will be better served by HF
> SSB, VHF simplex or perhaps even a traditional data mode such as
> Pactor or packet.
Each to their own on emergencies! I tend to focus on the local ones with
my participation in SES in Brisbane where storm damage and missing
person searches are the most common thing that we get called for. I've
been working with people from one of the specialist comms groups to see
how we would go passing messages when fax is down and it would take too
long to send the radiogram by voice.
> The more tools we keep in our toolbox, the more solutions we can
> build.  We have to know which tools to use and when.  Avoiding
> infrastructure for no good reason is as bad as being totally dependent
> on it, in my book.
You can never have too many toys!
> Simplex was quite popular around Melbourne before VK3RWN came about. 
> I found it very effective, and showed off D-STAR's RF performance,
> especially between fixed stations.  Stations I had difficulty working
> on FM simplex were Q5 both ways with 5W.
That's what Peter and I found with lumpy (a few hills but no real
elevation) terrain between us with a 20km path. I can only run 5W and it
certainly was more readable on DV than FM.

Mt Coot-tha is the best location for coverage of Brisbane proper from
what I've found (the 70cm FM repeater has great coverage and so does the
SES UHF repeater nearby). I was once considering helping to get a 70cm
Dstar repeater up there, but I have been put off by the problems that
are faced. I'm not sure that I could swing some space now that I don't
work for a company that has a site up there anymore. I do have line of
sight from home though, so getting an internet feed up there wouldn't be
a major hassle.  If there is a chance of this happening, or others have
similar ideas, please contact me off list.

Cheers,
    Dave.

-- 
David Ingram (VK4TDI)
Brisbane, Queensland, Australia
E: dave at ingramtech.com
W: http://www.ingramtech.com/
MH: QG62lm