[amsat-bb] Re: D-STAR experiment on Cubesat

[Nate Duehr]

On Jun 8, 2008, at 10:18 PM, David Donaldson wrote:

> Do we think that anyone other then Icom will ever support the mode?   
> I'd
> love to experiment with it on the birds but until there is  
> competition to
> drive the price down will that be possible.
>
> Maybe a GNU project?
>
> Dave
> WB7DRU
> Minnesota

D-STAR itself is an open protocol.  The CODEC is proprietary to DVSI  
(AMBE VOCODER) only.  The rest of it is possible for anyone to build to.

Satoshi Yasuda (7M3TJZ/AD6GZ) has a working D-STAR interface that  
requires nothing more than a radio with a standard "9600 baud packet"  
port on the back.  (Discriminator audio, and an unfiltered audio input.)

As far as AMBE, DVSI sells chips with the VOCODER embedded in them for  
about $20 in single-quantity pricing.  So it's possible to buy a $20  
chip and not worry about the proprietary bits -- and the rest can be  
done in software/firmware.  (This type of "use the DVSI chip, write  
the rest" model, is what the popular DV-Dongle is based on.)

As to whether or not others will support the mode... who cares?  They  
don't even have digital products out yet.  Until they do, they're now  
way behind, technology-wise.  I'm not even an Icom fan, and I've just  
bought two of their rigs, specifically for D-STAR... and not  
regretting it.  They're good analog rigs in that mode, no problems  
other than I don't like the audio quality of the ID-800H's mic, but  
that can be worked on...

Meanwhile... Yaesu/Motorola released yet another analog dual-band non- 
full-duplex HT.  Yawn.

Kenwood's busy merging with JVC and can't produce their popular dual- 
band HT because parts dried up on them before they could do a redesign  
on the internal boards.  Another Yawn.

Icom paired up with an outside organization (JARL) and worked on rigs  
for a completely new mode for hams to play with.   Much more  
interesting.

It sure would be interesting to get something with an AMBE CODEC (or  
convince DVSI to license the CODEC into an SDR) on-orbit... but not  
really necessary... since this "stuff" will pass through a transponder  
just fine, as evidenced by some folks who've done it.

--
Nate Duehr, WY0X
nate at natetech.com