D-STAR illegal in France

Well, perhaps things are different in Greece but it is not something I have ever come across. If people want better SNR, better range etc. they use SSB. I never heard anyone say "damn, if only we had digital we could make the contact." In Tokyo, perhaps, they have much more frequency congestion and so D-Star may meet a need there. But here in the UK now there is actually less VHF activity than there was 35 years ago when I was first licensed as a class B and 2m was the lowest frequency we could use.

I think it's quite right that experimenters should be free to develop digital voice modes and test how they perform. The thing that would motivate me to move to a digital system is seeing people do things I want to do but can't with the stuff I've got at the moment. But it also has to have a critical mass of users because it's no good how great your mode is if there are only three other people to talk to.

Whatever system is adopted should be compatible with free PC software that can interface with a radio using a sound card, or inexpensive add-ons that can turn existing rigs into digital-capable radios. That would quickly boost the numbers and, as long as people saw actual benefits, there might then be more of a willingness to upgrade to new purpose built digital radios.

 

Well, haven't you ever cried to yourself hearing some DX using just SSB and not CW? CW is considered by most to be digital!!!! (and of course, has every single advantage I mentioned earlier but it's skill reqquirement disadvantage stops it there. Imagine a world where within 1 KHz clear telephone quality could fit.

20m, the exclusively single most congested band,

could allow for 200 simultaneous QSO's in voice portions of bandplan instead of today's 60. Signals far too weak could pop out of the noise, making DXing easier over far more greater distances.

COFDM reception analysis could provide new aspects to the understanding of ionospheric propagation modes, how do they emerge and how they fade, when do they fade, and under which solar conditions. you could be finding things that explain a lot that normal PSK and FSK doesn't tell you.

A simple FPGA could handle the whole mode software processing, so we could have miniboards as we used to have adding CTCSS to older 2m rigs doing the new mode, even some of today's black box SDR radios could include them just by firmware update (did you know that the biggest fear of SDR radio makers is that someone will build an open source code which will render their radio bestseller and the next radio produced by them would be inferior to the former in the eye of the beholder, so noone would buy the new?), or new designs that could do the new mode in embedded SoC (system on chip).

Digital definately opens roads but one of those is narrower, has bumps, but still has tolls.



Once upon a time there were just a few PSK users. PSK grew up to be what it is today just by giving anyone tha ability to use it just by making a cable (or buying an interface box). I built a MAX232 converter in a box along with a pair of 600ohm transformers and a trimmer, and just like that I had a digital modes interface. HRD took over the rest, and I just paid 3 quids for parts. If digital voice is that easy, and hot as in easier DX, then many would step in the water to check it.

Still, there are some things to be considered. Some people do not recognise WSJT contacts over EME as valid, due to some unorthodox CRC routine (ie. QRZing the callsign and finding it even if 3 letters are mising, thus achieving the contact even by having -20db SNR.

Same problems could occur there as well. Others cry that cluster spoils the joy, because they scan the band all day long to get a DX and wait patiently until the DX finishes their started QSO only to have the DX spotted by someone else and mayhem follows. What to do? if it is the way to go, it's the way to go. Truth is that current modes are older than my Grandfather and I am already 33 years old...

We need to move forward.

 

Forward?

Some good points there John, but what's new is not always what's best.
Advocates of cd audio said the vinyl disc was 100% dead and here we are in 2010 with vinyl sales rising and cd sales dropping. That latter mainly due to online mp3 purchases of course, but why hasn't vinyl died? Because it sounds good.

"200 simultaneous QSO's in voice portions of bandplan" sounds like cb, throw away the vfo knob and replace it with a click selector and hey presto 20m channelized operation good buddy - 14MHz band goodbye from me.

PSK and WSPR type technologies are where we should be focusing our energies on, these are the modes with the highest potential to evolve. I'm stunned with the range of WSPR, what a fantastic mode.

I've never cried to myself when dx uses ssb over cw, it's the choice of the operator, lifes too short to get worked up about that sort of thing.

So what if that current modes are older than your Grandfather? it doesn't mean that they should be consigned to the trashcan, that's a really ageist comment and not a valid argument for DV.

If digital voice is to succeed, then it will have to offer real proven benefits and not just a replacement for SSB.

We in the UK are learning that to our cost with the DAB radio system our government are trying to force upon us. A poorly implemented COFDM system that you can't even use in a car without encountering massive bit error problems.

Back to amateur DV, I think the target should be narrower bandwidth, with the same quality as SSB and with the ability to establish & maintain solid DX contacts using much lower power than a regular SSB transmission. If it can't do that then it's not an evolutionary step and should be regarded as a dead duck.

 

I agree it has to be an evolutionary step, and therefore promoting D-Star now is wrong because it cripples the chance of better alternatives being developed just as the success of PSK31 has hindered the widespread adoption of other digital modes. As I said earlier, in ham radio it isn't just about how good the technology is but how many other people are using it so you always have someone new to work. If D-Star ever achieves the critical mass of users then it will be unstoppable.

Either we (hams in general) are going to be saddled with a white elephant taking up space in our bands and making it harder to find channels to use for alternative systems, or D-Star users are going to be saddled with obsolete radios as the system is upgraded to use improved technology. Because improvements and upgrading go hand in hand with digital systems.

In fact I think D-Star is going to usher in the age of the 3-year upgrade cycle for ham radios. Why not? It happens with other digital technologies like computers, mobile phones etc. All those 10 year old radios being sold on eBay and still doing useful service represent lost sales of new equipment. Now we have a way to make that equipment as obsolete as a Windows 98 computer. No wonder Icom is pushing it.

 

Good. I just wish the UK would follow suit.

 

The Star Wars Trilogy Continues....

D-Star = Death Star
Vive la France!!!
Vive la difference!!!

 

The D-Star Wars Trilogy Continues......

D-Star=Death Star
Vive la France!!!
Vive la difference!!!

 

The US wouldn't say that if they had oil....

 

BP would know all about that!!!

 

And that's why its damn important to get an open, free low-bitrate vocoder on the air ASAP. That's why I'm pushing so hard to see Codec2 developed.

As you've noted in your previous post, a free and open, evolved Digital Voice codec beyond current technologies would run rings around ICOM's DSTAR!

DSTAR as a mode is crippled by numerous factors:
1) The MINIMUM entry level for any ham is $200 for a DV dongle. For a standalone radio, quite a bit more.
2) Only one major vendor on the market
3) Proprietary codec, tied to a proprietary hardware platform (pre-burned DSP chip + support hardware) which limits experimentation to strictly hardware interfaces, no chance of a software implementation (without MEGA bucks)

Codec2 is currently being developed at a 2400 bit/s rate, however with wide implementation and lots of help, it could possibly go to 1200 bit/s or even lower!

The MELP (Mixed Excitation Linear Prediction - http://en.wikipedia.org/wiki/Mixed_Excitation_Linear_Prediction) family of proprietary vocoders can hit 600 bit/s and still remain intelligible. This is licensed to the US Govn't, and of course has MEGA BUCKS behind it (and an air-tight patent portfolio).

However, with STRONG open-source/ham community development, Codec2 or similar could be pushed to similar evolution! Just look at the LAME MP3 encoder software, or the whole Linux OS development community.

Of course, it's not an easy road. However, the market is there for an open-source digital vocoder that could easily knock the proverbial socks of DSTAR given the development resources!

 

once you have the software then it is like DV dongle or Echolink? Is this just a cheaper version of DV dongle?

 

Icom and D-Star

My main trouble with D-Star is only one company makes repeaters and or
radios "Icom". If you price any of them there way over price, the price of
the dual band with D-Star you can buy a low end HF radio there's even
a few HF plus 2 meter & 70 cm. radios cheaper or with in that price range.
Everytime Icom replaces a radio model the newer model cost $1000 more
then the older one was.
Icom can keep D-Star and there newer radios.

73,
N5DXL

 

If you're asking about AMBE software-based vocoder... it's in the (tens?) thousands of dollars to licence it from DVSI Inc.

A software-based Codec2 would be a free, open and portable mix between PSK31 and Echolink - It would be *standalone* like PSK31 (no Echolink registration/internet connection/etc required), however like Echolink it would allow voice through your computer.

Once developed, you could easily make a Codec2 iPhone App, hook up some audio cables and pair it with your mobile or HT!

This would be assuming a *simple* simplex or repeater setup. That assumes you're not using it as part of the DSTAR network, which is a whole another topic. In that case, you'd need a "wrapper" software that would implement the DSTAR protocol in addition to the Codec2 vocoder.

 

I agree, it should be developed. Then the idea can stand or fall on its own merits. We, the users, will decide.

You have already pointed out the disadvantages of having a system that uses a closed codec. But what really annoys me about D-Star is the way certain influential people (and bodies like the RSGB) have apparently decided that D-Star is the future without asking anyone or considering that it might be better to wait and see if something better comes along.

Hams should decide what modes should be used in our bands, not commercial interests.

 

And that's the whole crux of the issue... Bingo!