Re: Internet Fail & Cell Weakness = Need for Ham Network?

Matthew Pitts <daywalker_blade_2004@...>
 

Maybe because it's relatively simple to generate GMSK in software whereas 4FSK/C4FM requires (to the best of my knowledge) a dedicated IC to handle the timing; I know that GMSK demodulation has been included in GNURadio since at least 2005 (and the GMSK demodulation in that is written in Python). I think someone from Icom even explained why they chose GMSK over the other options for D-Star in an interview done at the Orlando Hamcation this spring.

Matthew Pitts
N8OHU


From: Trevor .
To: UniversalDigitalRadio@...
Sent: Sunday, July 29, 2012 2:15 PM
Subject: Re: [UniversalDigitalRadio] Internet Fail & Cell Weakness = Need for Ham Network?

 
--- On Sun, 29/7/12, Mickey Baker <fishflorida@...> wrote:
> It is simply a classic example of a cascading market and Icom is to
> be commended in creating and driving the market - after all, at less
> than $300M worldwide, they're a relatively small company driving big
> ideas.

And the commercial side of ICOM saw the light and along with Kenwood went for C4FM (4 level FSK) back in 2005 and they haven't looked back since.

http://www.southgatearc.org/news/apr2005/icom_kenwood_demo.htm

The mystery has been why the amateur radio division of ICOM has persisted with GMSK all these years.

BTW doesn't the original ABME vocoder chip become free of copy restrictions in 2015 ?

73 Trevor M5AKA
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