What is ideally wanted is for Codec2 and also FDMDV to be commercially 
exploited by the major amateur radio companies. 

The development of a digital voice system by G4GUO back in 1999 was picked up 
by the company AOR who produced the AOR ARD9800 SSB digital voice modem.

As a product it failed because there was only one company producing equipment 
but it illustrates that amateur radio companies will pick up free software and 
incorporate it into their products which is a good sign. 

On the VHF/UHF hand-held front there's a lot to be said for the use of 4-FSK 
modulation which permits the use of high efficiency PA's. But there's no reason 
why you can't have a narrow band handhelds with lower efficiency linear PA's. 
What you lose in efficiency you more than make up for in improved S/N from a 
1.4 kHz bandwidth signal.

73 Trevor M5AKA

--- On Fri, 11/5/12, Peter <getroo...@gmail.com> wrote:

From: Peter <getroo...@gmail.com>
Subject: Re: [Freetel-codec2] PAPR and handheld operation
To: "Codec 2 Mail-list" <freetel-codec2@lists.sourceforge.net>
Date: Friday, 11 May, 2012, 19:37

On 11 May 2012 19:27, Bruce Perens <br...@perens.com> wrote:


  
    
  
  
    On 05/11/2012 11:06 AM, Peter wrote:
    

      No matter how little bandwidth we use on VHF/UHF, it's likely
      we'll be occupying a whole 12.5khz channel anyway due to the way
      FM radios are designed (assuming home brew addon kit here).

    
    I think you should assume that our major deployment on VHF/UHF would
    be a manufactured-for-purpose radio, rather than a homebrew dongle
    on an existing HT. 

    

    If you are only proposing this D-STAR variant for experimental
    use, go on as you are, but be aware that it would probably be
    succeeded by a different implementation in purpose-built equipment.

    

    We have the potential, in a purpose-built radio, to offer:

    
      Really narrow-band channels, like 2 KHz. This will be
        welcomed in places like California where we have lost much of
        our 440 repeater operation to PAVE PAWS and thus need more
        channels on other bands.
      Proportionally better range for the input power, which is very
        important to users.

      
    
            Thanks

    
            Bruce

    
  

For some reason this went to you and not the list. I think because you CC'd the 
original to me direct as well as the list. Anyway shifting it back to the list.

I think mainly I was looking at homebrew + hardware to be added onto radios 
(external kits) or modified into the radio. DVRPTR style for example.


So many times I hear people complain that the experimentation/home brew aspect 
from amateur radio is being diminished. Indeed it's my own personal pet peeve 
with D-star, that the codec is closed and you need to buy a chip just to use 
it. So it's for this reason that I see codec2 as a good way to resolve that, in 
the digital age. I don't really have the know-how to design a modem from 
scratch, for sure I don't have the time. My programming experience is a mile 
away from this. I do know how d-star works and I know the caveats for 
implementing a VHF DV system. There's also an overlap with my real world 
programming experience which is from a design perspective and also that 
essentially designing a lean data protocol with real time demands really is 
quite similar to some of the EDI projects I've been involved with. I'm also 
fairly confident all the building blocks to make this work already exist and 
just need a protocol, and then be brought together.


In any case, I think that projects using standard FM channel bandwidths and 
those using lower bandwidths can peacefully co-exist (they're not performing 
the same task). It's when we start making competing standards for the same 
purpose, things get a bit confusing for everyone. In fact, the FDMDV will work 
fine on SSB on VHF/UHF too. In fact, I am tempted to get some of my club 
members involved in this regard at the very least. Quite a few that are into 
digital modes in general. But that's another story.



Best regards,


Peter.


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