[Dstar] D-Star Simplex

[Tony Langdon]

At 07:52 AM 9/4/2009, you wrote:

>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

Well, those localised emergencies usually leave infrastructure mostly 
intact, so there's certainly choice as to the tool to use, and D-STAR 
in all its forms has its attractions.

>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.

Well, if you used D-STAR, then adding D-RATS is an obvious option. :)

>You can never have too many toys!

So true!! :D

> > 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.

Yes, DV is extremely good in the region where FM signals get 
noisy.  Provided there's no multipath issues, DV does some amazing 
things.  Multipath (especially while mobile) does reduce effective 
range somewhat, due to loss of sync, but even then, it's often still 
on a par with 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.

You might want to assemble a team to pull it off.  Well, from what I 
see, Brisbane is going to be the D-STAR capital of the country, going 
by the number of installations planned for the area.

73 de VK3JED / VK3IRL
http://vkradio.com