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. -----Inline Attachment Follows----- ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ -----Inline Attachment Follows----- _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2