First satellite QSO using D-STAR Digital Voice

[g4tut]

First amateur satellite QSO using D-STAR digital voice

What is believed to be the first Amateur Satellite QSO using the new Digital Voice Mode D-STAR took place on July 1st between Michael N3UC and Robin AA4RC using the AO-27 Amateur Satellite.

This report from http://www.ao27.org/

On July 1st, 2007 during the 20:00 UTC pass over North America, AO-27 was again providing a new round of enjoyment for Amateur satellite experimenters.

Thirteen years ago, AO-27, which coined the term "Easy Sat" by employing an FM bent pipe in space, provided many hams the ability to use a satellite without the expense of multi mode radios.

This time around, AO-27 was used to provide the first D-Star via Satellite contact between Michael, N3UC, FM-18 in Haymarket VA and Robin, AA4RC, EM-73 in Atlanta GA. Signals were reported as strong and easy to copy.
Call signs were received digitally on both sides of the link. Communications were possible for most of the pass.
Both Robin and Michael were surprised at just how well thedigital link was received.

The Analogue repeater on-board AO-27 is well suited for D-Star work. The radios were designed to pass 1200-19200 baud GMSK data. The Analogue mode was not a primary mode of operation in the design. Using a free switch setting in the switching board, the design team hooked up the output of the receiver to the input the transmitter to create the Analogue mode. There is not the normal low frequency filtering that is found in normal FM Repeaters. This means the Analogue mode passes the low frequencies required by D-Star.

The equipment for the contact were IC-2200s on the Uplink at both N3UC and AA4RC, an IC-2820 on the downlink at N3UC, and an IC-91AD on the downlink at AA4RC. Doppler shift did prove to be a minor problem while using these radios.

The D-Star signal would decode out to about 1.5 KHz in frequency error. The IC-2820 would only tune on 5 KHz spacing (the 6.25 KHz channels did not fall in the right locations to help.) so at times we could not decode the digital signals.

For others that want to try D-Star via Satellite we have a few things to keep in mind.

1) Remember that the FM users can't hear you on the bird.
They hear a strong "noise" but can't decode you. So please keep the D-Star transmitting short.
If you can monitor the FM side, you can time your transmitting as to not step on them.
Please try to schedule with other D-Star users instead of calling CQ for the entire pass.

2) Watch the doppler, at times you may not be able to decode a signal even if the other station can decode you.
Keep your uplink on 145.850 for the entire pass. Program your radio call signs the same as for simplex, AO-27
does not have a D-Star call sign. You don't need to set up your radio for repeater use.

3) Before using other satellites besides AO-27, please check with the control operators of those satellites. Every
FM satellite may not pass the D-Star signal nor may the control operators wish to have D-Star traffic on the bird.

4) If you hear us on the Bird, please give us a call. We would love to have as many D-Star users on AO-27 as possible.

The AO-27 Control Operators fully support and encourage the use of D-Star via Satellite on AO-27.

A shout goes out to ICOM for creating Radios for this Fun new Amateur mode of operation. Without their radios we could not have made this contact.

Michael N3UC
AO-27 Control Operator

--------------------------------------------------------------------------------

AMSAT-UK will be holding their 22nd International Space Colloquium at the University of Surrey, Guildford, England from Friday 20th to Sunday 22nd July.
see http://www.uk.amsat.org/Colloquium/

AMSAT-UK publish a quarterly newsletter OSCAR News.
For membership information contact the secretary Jim Heck G3WGM
Tel: +44 (0)1258 453959
Email: g3wgm@amsat.org
Join online at https://secure.amsat.org.uk/subscription/

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[KG4RUL]

Oh joyous rapture! http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

[N3CRT]

Expensive radios that dont work all the time on the Satellite? No thanks I'll stick with my IC-910h. It may be expensive but it doesnt drop out.

[ky5u]

Congratulations guys!

[wa6itf]

Quote[/b] (N3CRT @ July 04 2007,06:48)]Expensive radios that dont work all the time on the Satellite? No thanks I'll stick with my IC-910h. It may be expensive but it doesnt drop out.
Even with the Doppler induced drop-outs, it is a rather noble first time achievement. If anything, it shows that the terrestrial radio gear will need to be improved to that it can tune in smaller increments such as 100 Hz steps or such.

If satellite operation of D-Star become popular, then I suspect that Icom -- or some other manufacturer -- will bring out gear specific for this type of utilization. Another though far more costly solution would be to launch into geosynchronous orbit three "TDRS-like" satellites that could be linked together to permit terrestrial hams to "talk" or exchange "data" in real time from any spot on the globe to any other spot on the globe.

Right now the two biggest complaints I as a writer hear are that ham radio satellites require stations be equipped to track them and that they are not available 24 hours a day / 7 days a week. Once satellite operation comes of age to where a given terrestrial station need only have an antenna fixed to one location in the sky, I suspect that you will see many more -- if not most of the worlds radio amateurs give it a try.

Technology is ever moving forward, A good example is FM which did not come of age until the first repeaters came on the air back in the late 1960's. A decade later, almost every ham owned some sort of FM transceiver -- at least for 2 meters -- and there were some 3500 repeaters in operation in the USA. By 1990 there were about 9500 FM repeaters world-wide and growth did not level off until about 2002.

Whether or not D-Star will be a catylist that pushes the worlds various AMSAT groups to think in terms of providing the global ham radio community with a system of digital ready, interlinked geosynchronous ham radio utility communications "Easy Sats" I cannot say. Its just far to early to know. But in the big picture, this D-Star experiment -- and in reality is is just an "experiment" -- does open the "ham radio digital door" a bit wider. And is not "experimentation" that leads to "utility" really an important part of what ham radio is really all about?


de
WA6ITF

[K4JF]

Quote[/b] (wa6itf @ July 03 2007,11:33)]And is not "experimentation" that leads to "utility" really an important part of what ham radio is really all about?

de
WA6ITF
Absolutely! In spite of what a lot of posters on here say.

[NL7W]

Quote[/b] (K4JF @ July 04 2007,12:13)]Quote[/b] (wa6itf @ July 03 2007,11:33)]And is not "experimentation" that leads to "utility" really an important part of what ham radio is really all about?

de
WA6ITF
Absolutely! In spite of what a lot of posters on here say.
So true.

A little experimenting or Research, Development, Testing, and Evaluation (RDT&E) is always a good thing -- if only to find out what doesn't work.

73.

[wb3dye]

I think it's great that digital has come to ham radio but I do have a question.
Why aren't we using APCO Project 25 digital? #It's becoming the national standard for public safety comms.

It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck. If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

[NC5P]

Quote[/b] ]Why aren't we using APCO Project 25 digital?

Because the royalties on it are totally rediculous. D-Star uses the AMBE vocoder, a second generation vocoder after IMBE (P-25) but they charge a very small fee for that one.

There are quite a few hams using P-25 and a number of repeaters out there. I don't know if anyone has used them through satellites? Perhaps someone will speak up.

[k5okc]

Quote[/b] (wb3dye @ July 04 2007,20:50)]Why aren't we using APCO Project 25 digital? #It's becoming the national standard for public safety comms.
Who cares. #Public Safety isn't ham radio.

Quote[/b] ]It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck.

If you want to be a fireman or an ambulance driver, then join the force.

Quote[/b] ]If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders.

Hams should stay off Public Service frequencies. #If you want to communicate directly with first responders, have them give you a radio. #It's probably encrypted anyway.

[wa6itf]

Quote[/b] (wb3dye @ July 04 2007,18:50)]I think it's great that digital has come to ham radio but I do have a question.
Why aren't we using APCO Project 25 digital? It's becoming the national standard for public safety comms.

It could get to a point that those of us who have public safety frequencies plugged into our FM 2 meter/440 radios will be out of luck. If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
Several reasons. First is that APCO-25 is not a free format. To manufacture equipment for it means that the maker has to pay a royaltee fee which in turn gets passed onto the customer.

As such the next reason -- that fee along with full type acceptance as required by the FCC places APCO-25 compliant radios out of the reach of most hams. And ham manufacturers know that radio amateurs will not shell out $1000 for an HT or $2500 for a mobile radio. On the other hand, D-STAR -- which was developed by the Japan amateur Radio League i in the public domain and is royaltee free. Anyone can make and sell D-STAR compliant radios albeit only Icom has to date.

All Icom has to do is recoup its research and development costs whereas those making and selling APCO-25 radios have the ongoing expense of royaltee fees for each radio delivered. So from a business position, APCO-25 make very bad ham radio business sense.

de
WA6ITF

[aa1mn]

Wow, all that expensive equipment - all that time - for two people to communicate with each other. They must have money to burn. Wonder if either of them considered a less expensive investment of email (you don't even need your own computer can use one at a local public library - for free - using a yahoo or hotmail account - also free - to kepp in touch), pick up a phone and dial each other up (a decent Verizon plan is less expensive than the cost of amateur radio gear as I well know as I have such a plan), or the cost of a .41 cent stamp would do the job just as well.

Hey guys, since ya got cash to toss away how about sending some my way?

Chuck, AA1MN

[ka9uce]

D-Star would be a great tool for experimentation, but the initial cost is prohibitive for many, myself included.

While the kudos to those that have and use it are at hand, many can not justify the much higher cost of the equipment and therefore, have to forego the experimantal stages amost out of hand.

P25 is crap as well...expensive royalties to D.V.I to produce a CODEC, and regardless of what many may think, P25 is NOT interoperable throughout the nation as many locales can not afford such costly infrastructure, and have no real need as well.

P25 was billed as the end-all for everything, and in the 'end', most are finding out it's incapable of real world usage, given geographical constraints, simulcasting requirements and multiple repeater sites....it doesn't make financial/fiscal sense, same goes for D-Star.

The ID-1200 appeared to be a neat radio, UNTIL you saw the price!!

Not to mention how many 1.2Ghz systems are there in this country that are operational AND being used as well?

I'll bet there's less than FIVE.

Even the IC U-82 and V-82 were cheap in initial cost of purchase....UNTIL you decided to add the D-Star board, then the cost of that radio jumped from under $100.00 to over $300.00, with 80% of that cost being for the digital board!

Sorry, but D-Star is NOT worth that much to me for playing with, not when I can pick up an Astro Saber with IMBE vocoder for about the same cost, plus I have a radio that can be used for business PLUS amateur radio too.

If you have the $$ to toss around for D-Star and have a digital repeater in operation also, then why stop there.
Go commercial and pay big $$ for a Datron, or an XTS 3000/5000 or even the 2500 with FPP.

No wonder the big names build and sell $20,000.00 H.F rigs....there must be a lot of hams with money burning holes in their wallets, or they have a HUGE spending limit on their credit cards!

D-Star is no different...playing up to those willing to spend any amount on new toys, too bad they'll have nobody to talk to once they power it up.

Don't get me wrong, I LOVE the technology, it's just too far in its infancy to be of real value yet, maybe over the course of the next five years the cost to own them will drop to a level most will no longer find objectionable, but for now, it's pretty much a rich man's game, and that in itself is sad.

[K0RGR]

For some of us, there is another reason I'd prefer not to see APCO 25 in my radios.

Here in the People's Republic of Minnesota, we have the country's most anal-retentive anti-scanner law. While the law does exempt amateur radio transceivers, hams are required to show any officer who inquires their license. This means that if my wife or daughter drive my car, they may face a jail term.

Fortunately, our local police and sheriff's offices have moved over to APCO-25 trunked digital, and within a few years, the whole state should be that way. At that point, I will no longer have a radio 'capable of receving public safety transmissions', so I shouldn't have to worry about my ham rigs or any analog scanner. If the radio is DSTAR, it still won't matter.

Congrats on this 'first'!

[kb2wye]

Holy RF Batman!!!!!!!!!!!!!

[w4hv]

OH MY! Was it not LT. Commander Montgomery Scott who stated "The more you complicate the plumbing the easier it is to screw up the pipes!"..Congrats on doing the contact are in order. But now exactly why do we need to use a bandwith hogging digital mode to convey what can easily (and with less bandwidth) be conveyed currently. By the very nature of its being it does not compare with the efficieny of a standard SSB or FM signal...I know all about compression routines and hopefully one day the D-star or some other mode will be improved to the point of actually making it useful and practical.
As I understand ham radio we need to experiment to expand our knowledge and to develope such technology. That being understood its not always practical to use the most moden thing out there to get reliable communication...Until we see the place where we should be using this technology (up in the gigahertz range), we should be careful to guard our fully functional systems of communication. So great work on doing it! Now put it where the bandwidth won't compromise the learning curve on standard satelite communications..
Not everyone gives a hoot about research...And many can't understand why you would bother...I do understand the need to grow...But not at another group of peoples expense...

[N2RJ]

Congratulations!!! Go D-STAR! Go Digital!!

[W5HTW]

Quote[/b] (k5okc @ July 04 2007,20:00)]Quote[/b] (wb3dye @ July 04 2007,20:50)]Why aren't we using APCO Project 25 digital? It's becoming the national standard for public safety comms.
Who cares. Public Safety isn't ham radio.

Quote[/b] ]It could get to a point that those of us who have public safety frequencies plugged into our FM 2 meter/440 radios will be out of luck.

If you want to be a fireman or an ambulance driver, then join the force.

Quote[/b] ]If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders.

Hams should stay off Public Service frequencies. If you want to communicate directly with first responders, have them give you a radio. It's probably encrypted anyway.
Exactly. Exactly! Exactly!!! Precisely. Darned right.

Thanks for saying that. If we could stop playing cop long enough to get back into ham radio, we'd have a heck of a lot more fun -- and more experimentation.


Ed

[wa4gch]

"Remember that the FM users can't hear you on the bird.
They hear a strong "noise" but can't decode you. So please keep the D-Star transmitting short.
If you can monitor the FM side, you can time your transmitting as to not step on them. "

Hummmmmm ....

After seeing how the digiboys acted on taking over other bands how long will this last ...... since FM, SSB and CW are LEGECY modes not worthy of bandwidth ....



One can hope ill be proven wrong ....

[ky5u]

Quote[/b] (K4JF @ July 04 2007,12:13)]Quote[/b] (wa6itf @ July 03 2007,11:33)]And is not "experimentation" that leads to "utility" really an important part of what ham radio is really all about?

de
WA6ITF
Absolutely! In spite of what a lot of posters on here say.
I think most amateurs support experimentation, just not on top of more popular modes on HF. Experiment all you want on VHF and above, and on a limited basis on HF.

I also see this is sliding into a D-Star versus P25 discussion. Lets congratulate these folks for their noteworthy achievement and take the snivel about P25 elsewhere.

[KE7CDV]

Quote[/b] ]On the other hand, D-STAR -- which was developed by the Japan amateur Radio League i in the public domain and is royaltee free.

The standard is, indeed, in the public domain and open, but it calls for using AMBE codec from Digital Voice Systems, Inc. (DVSI) which is not free (but apparently is pretty cheap). #I don't think there's anything inherently wrong with that (the intellectual property in the AMBE codec is significant, and even if you had the spec, parts of it are probably patented anyway), but I wish the codec were available in a form other than a physical IC that you purchase. #If DVSI licensed the source code for the codec, it would make it possible to use D-Star as a "sound card" mode on laptops, for instance -- this would really help out the mode's popularity and acceptance, I think.

So... having said that... I'm all for continuing D-Star development/experimentation, since it demonstrates some nice technological advances, but I'm also a big advocate of amateurs cooking up their own codec that's reasonably comparable in quality to DVSI's and making it 100% freely available. #

I disagree with the folks who think amateur radio experimentation is a "rich man's" sport. #It's certainly no more expensive than many other hobbies, and in real dollars radios today are much cheaper and more feature-laden today than they were 20 years ago. #Amateurs have also been incredibly resourceful when it comes to conserving money -- I still don't know how AMSAT manages to get so many amateur satellites put up, when commercial ventures wanting to do so would typically be paying millions of dollars for the task!

---Joel Kolstad

[KE7CDV]

Quote[/b] (w4hv @ July 05 2007,13:15)]
Quote[/b] ]But now exactly why do we need to use a bandwith hogging digital mode to convey what can easily (and with less bandwidth) be conveyed currently.

Umm... no. D-Star doesn't occupy any more bandwidth than a standard NFM channel: D-Star is ~9kHz, most radios occupy ~10-16kHz (depending on their deviation and the audio input) in NFM mode!

Quote[/b] ]By the very nature of its being it does not compare with the efficieny of a standard SSB or FM signal...

You're right, arguably D-Star is more efficient. :-) Look, I'd be the last guy to claim that D-Star is "all pros" and "no cons" or that other modes have no advantages over D-Star -- they certainly do. But D-Star is a legitimate advancement in amateur radio, and I think it's fair to say that anyone who starts using it ends up preferring it in many cases over conentional NFM or SSB.

Quote[/b] ]Until we see the place where we should be using this technology (up in the gigahertz range)

9kHz is a reasonable bandwidth for 2m, IMO. D-Star does have a 128kbps mode -- occupying something like 130kHz -- that they advocate for 1.2GHz and higher; I think everyone would agree that occupying 130kHz on 2m is a Bad Idea. :-)

Quote[/b] ]I do understand the need to grow...But not at another group of peoples expense...

At least where I live, about 90% of the amateur bands on VHF and above are completely dead much of the time. There's plenty of open bandwidth to experiment in without stepping on anyone's toes.

---Joel Kolstad

[n1dvj]

Quote[/b] (wb3dye @ July 04 2007,18:50)]It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck. If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
I hope you don't think I'm picking on your for this, but ... Wow, is this dangerous or what?

Just what HAM radio needs for an image, wacker HAMs breaking in on police frequencies to report stranded motorists or blinking traffic lights. #And you KNOW that will happen!

It's one thing to 'listen in' on public service, but quite another to even THINK about being able to break into them, even just for 'emergencies'.

By the way, unless something has changed, I'm pretty sure it would be illegal. #That would make the radio 'multi service' and in violation. #Even if you have a VHF/UHF frequency as a business, it is ILLEGAL to make your HAM radio go there and transmit. #It COULD be legal for you to have a business or public service radio and to to HAM frequecies and transmit, but ONLY if the commercial radio is certified for it, and then that's not very likely to happen. #One manufacturer a few years ago got into an issue where one of their radios could 'sweep' the spectrum if it went from a HAM frequency to a business frequency and was keyed. #Besides, why would a business radio manufactuer even care?

[W9WHE]

D-STAR.....

ONE SMALL STEP FOR ICOM, ONE GIGANTIC LEAP BACKWARDS FOR HAM RADIO COMPATABILLITY.

APCO P25 IS THE WORLD-WIDE STANDARD FOR DIGITAL COMMUNICATIONS. WHAT IS D-STAR?

W9WHE

[wc4rav]

Quote[/b] (W9WHE @ July 06 2007,14:20)]D-STAR.....

ONE SMALL STEP FOR ICOM, ONE GIGANTIC LEAP BACKWARDS FOR HAM RADIO COMPATABILLITY.

APCO P25 IS THE WORLD-WIDE STANDARD FOR DIGITAL COMMUNICATIONS. WHAT IS D-STAR?

W9WHE
the next phase of p-25
p-25 phase 2 employs ambe like d-star and some manufactors even have applications that behave very much like D-star check out Ip-25

[wa4gch]

I was wondering is D-STAR the same as DEATH STAR ? And is P-25 a friend of R2D2 ?

[K4JF]

Quote[/b] (W9WHE @ July 05 2007,15:20)]D-STAR.....

ONE SMALL STEP FOR ICOM, ONE GIGANTIC LEAP BACKWARDS FOR HAM RADIO COMPATABILLITY.

APCO P25 IS THE WORLD-WIDE STANDARD FOR DIGITAL COMMUNICATIONS. WHAT IS D-STAR?

W9WHE
D-Star is the worldwide standard for Amateur communications. An advance, not a backward move, toward digital compatibility (if that's what you're looking for).

APCO P-25 is proprietary and expensive, thus disqualifying it for an amateur standard. There is no need to go there if D-Star is just as good (I don't know, but I hear it is).

[K4JF]

Quote[/b] (n1dvj @ July 05 2007,09:16)]Quote[/b] (wb3dye @ July 04 2007,18:50)]It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck. If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
I hope you don't think I'm picking on your for this, but ... #Wow, is this dangerous or what?

Just what HAM radio needs for an image, wacker HAMs breaking in on police frequencies to report stranded motorists or blinking traffic lights. #And you KNOW that will happen!

It's one thing to 'listen in' on public service, but quite another to even THINK about being able to break into them, even just for 'emergencies'.

By the way, unless something has changed, I'm pretty sure it would be illegal. #That would make the radio 'multi service' and in violation. #Even if you have a VHF/UHF frequency as a business, it is ILLEGAL to make your HAM radio go there and transmit. #It COULD be legal for you to have a business or public service radio and to to HAM frequecies and transmit, but ONLY if the commercial radio is certified for it, and then that's not very likely to happen. #One manufacturer a few years ago got into an issue where one of their radios could 'sweep' the spectrum if it went from a HAM frequency to a business frequency and was keyed. #Besides, why would a business radio manufactuer even care?
It is perfectly legal to modify commercial equipment for operation on ham frequencies. #That has been done for decades, and the commercial radio does NOT have to be "certified for it". #The reverse, however, is illegal.

[ka9uce]

Quote[/b] (n1dvj @ July 06 2007,01:16)]Quote[/b] (wb3dye @ July 04 2007,18:50)]It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck. If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders. http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
I hope you don't think I'm picking on your for this, but ... #Wow, is this dangerous or what?

Just what HAM radio needs for an image, wacker HAMs breaking in on police frequencies to report stranded motorists or blinking traffic lights. #And you KNOW that will happen!

It's one thing to 'listen in' on public service, but quite another to even THINK about being able to break into them, even just for 'emergencies'.

By the way, unless something has changed, I'm pretty sure it would be illegal. #That would make the radio 'multi service' and in violation. #Even if you have a VHF/UHF frequency as a business, it is ILLEGAL to make your HAM radio go there and transmit. #It COULD be legal for you to have a business or public service radio and to to HAM frequecies and transmit, but ONLY if the commercial radio is certified for it, and then that's not very likely to happen. #One manufacturer a few years ago got into an issue where one of their radios could 'sweep' the spectrum if it went from a HAM frequency to a business frequency and was keyed. #Besides, why would a business radio manufactuer even care?
I see this conversation is getting waaayyyy out of touch with what it started out as...

First off, to those making wild comments about hams using public safety frequencies....nothing was ever mentioned about this!

Stay focused, the conversation is/was about the differences between P25 and D-Star, NOT some joker talking on P.S channels.

And for correction, anybody using a radio that is deviating SIXTEEN KILOHERTZ is SURELY being heard well outside the legally authorized emission bandwidth of just TEN KILOHERTZ, actually, less than that in proper usage.

8 Khz. either side of the carrier frequency is nuts!
And that radio should be aligned before it's put back into service, and if not then smash it with a hammer to make sure it never gets used again.....it's JUNK!

P25 has its place, as does D-Star, neither are the two of these modes the end-all-do-all to ham radio, they are simply another mode of operation, don't bash what you've never tried.

If you are a ham with big money, then get a P25 repeater up and running, same goes for D-Star, both are legal and afford challenges plain FM repeaters don't suffer from...yet.

Just as I am all for using encryption on ham radio....as there are times when it's a good thing to keep certain people from 'tuning in'.

Besides, even if you are using DES-XL, its algorithm has already been broken in minutes now, so in actuality, only those with super computer access may possibly have the ability to crak your coding, but highly unlikely as to be all but impossible, especially to 'normal' hams.

People don't like it because all they see are the nefarious things one can do while 'cloaked'...But I don't think the Romulans are going to attack soon, and if there are those with bad intentions, it will be used regardless of a rule, so in reality, what IS the difference if it's allowed or not?

Honest people would not use it, and crooks would no matter what, so the 'law' or 'rule' has NO real effect, except as a 'feel good' measure for bleeding heart purists who think laws are always adhered to by everybody.

That's okay, I'll never tell if you always drive above the posted speed limit( but it is a 'law' regardless, and we ALL break that one daily).

Besides, P25 is not just for public safety, anybody can use that digital mode, it's just a little cost prohibitive for the time being, but not forever.

There are plenty of Astro Sabers and used XTS portables with digital operation flashed into the firmware...you just have to look and be willing to pay to play, that's really all it boils down to....money.

And just what constitutes 'dangerous' anyway, when it involves life or property?

Is simply being able to USE a digital mode to talk on a P.S frequency 'dangerous', or is it simply because it's allocated TO public safety that makes it so?

Recall if you will, that ANY form of communications is LEGAL if the circumstances require aid for life or property, or imminent danger to same.....ANYTHING GOES, and this includes ALL radio frequencies.

If you are in a boat on the 'high seas' and have a marine radio you don't have a license for, and you are taking on water, are YOU going to leave it off, or pick up the mic and call for help?

I KNOW what the proper answer to THAT question is...YES!

And rightly so....same goes for using P.S frequencies.

But I digress...this is NOT what this particular forum is about.

I'm fro DStar and ANY digital mode we care to implement, even the P25 'standard'.

[n5rfx]

Quote[/b] (ka9uce @ July 06 2007,13:29)]And for correction, anybody using a radio that is deviating SIXTEEN KILOHERTZ is SURELY being heard well outside the legally authorized emission bandwidth of just TEN KILOHERTZ, actually, less than that in proper usage.
An FM radio that has a 5 KHz deviation and whose highest audio frequency is 3KHz has a bandwidth of 16KHz according to Carson's Rule (http://www.fmsystems-inc.com/eng_fm.htm). This is F3E modulation. F1E can be more bandwidth efficient and provide an equivalent SNR and audio bandwidth. DSTAR for voice has an occupied bandwidth of 6 KHz. DSTAR Spec (http://www.arrl.org/FandES/field/regulations/techchar/D-STAR.pdf)

73,
Mark N5RFX

[n1dvj]

Quote[/b] (K4JF @ July 06 2007,20:06)]It is perfectly legal to modify commercial equipment for operation on ham frequencies. #That has been done for decades, and the commercial radio does NOT have to be "certified for it". #The reverse, however, is illegal.
Correct. #You can take almost ANYTHING and put it on HAM frequencies as HAM equipment. #There really is no difference from taking a whole unit and making it work on HAM frequencies as opposed to taking individual parts and building a radio. #You are correct in that there is NOTHING that has to be done for radios for use on HAM frequecies by individual HAMs.

However, depending on the mods you do, you MAY be invalidating the radio for use on it's original frequencies.

Normally you would think that just 'adding frequencies' to a broadband radio wouldn't cause a problem. #It's just frequencies,right? #However a number of years ago there was a commercial PS radio that happened to be modified by a lot of 'firemen' and others in public service to cover popular HAM 2M frequencies. #The manufacturer had a fit due to the fact because under certain conditions the radio would 'sweep' the entire spectrum at full power transmit until it locked, and allegedly one of the conditions that set up the unit to have this problem was programming 2M into the unit with the other frequencies way back up in the PS areas. #So in that case, just putting 2M frequecies into the units would set up conditions to invalidate the unit for operation in the PS area.


Quote[/b] (KA9UCE @ July 07 2007,12:29)]
And just what constitutes 'dangerous' anyway, when it involves life or property?

Is simply being able to USE a digital mode to talk on a P.S frequency 'dangerous', or is it simply because it's allocated TO public safety that makes it so?

Recall if you will, that ANY form of communications is LEGAL if the circumstances require aid for life or property, or imminent danger to same.....ANYTHING GOES, and this includes ALL radio frequencies.

If you are in a boat on the 'high seas' and have a marine radio you don't have a license for, and you are taking on water, are YOU going to leave it off, or pick up the mic and call for help?

I KNOW what the proper answer to THAT question is...YES!

And rightly so....same goes for using P.S frequencies.
Hey, no kidding! You do what you have to do. But I wasn't refering to what would be considered life threatening circumstances. I'm refering to the wacker HAMs that are out there. You know who they are, I'm sure. Even just on HAM frequencies with HAM only activities, they're the idiots that during severe weather nets, with net control starting to get overwhelmed as power is being knocked out and BEGGING people to report only branches larger than 6" coming down from the wind or hail 1/2" or larger, who just have to break in to say "It just started to drizzle here" kind of thing. 'Wackers' The dark side of HAM radio we don't want to acknowledge even exist.

Do I have a 'modified' radio in my car? Sure. But I didn't modify it to get on PS. I modified it because it was 'all or nothing' with my radio. One mod opened it up, and it wouldn't do cross band repeat without full transmit capability. Personally, I've considered UNDOING the mod.

I liken the ability to do a mod to other situations in my life with the capability is nice, but it has to be kept under control. I worked for a company once that said if a robber came in give them what they want. No guns, no resisting, be sheep. Ok, fine, that's policy. But when the place next door got hit, and the two employees were taken into the back room and pistol whipped to give the robbers more time to 'get away'... I put a 357Magnum behind my filing cabinent positioned so that if I was being led into the back room with my hands raised it was 'right there'. I figured if I used it I would be fired almost as fast as the company got the info. But then it was my life or well being vs the job. Job looses.

Sometimes yes, you have to break the rules to do what is right, or to protect yourself or those you care about, and you are willing the accept the consequences of those actions.

However, there are those 'wackers' out there that just don't know how to tell the difference and where lines should be crossed. OK, make anyone who transmits on PS frequencies INSTANTLY loose their HAM license for 1 year. Subject to reinstatement IF JUSTIFIED upon review (and ONLY if there were NO OTHER means of communication, like cell or even a pay phone). AUTOMATICALLY suspended INSTANTLY for getting on PS. Would you transmit to save someones life? Report a robery? Report a suspicious person? Where do you draw the line? There are people NOW who abuse it!

[ab8yy]

Is there any ability to receive DStar or transmit it with soundcard software yet?

As far as DStar goes, I have no problem with it as long as the league doesn't try to use it to remove legacy modes. AS for encryption, there is no place for that on ham radio. Period - none. Encryption is for thepurpose of hiding the tranmitted information - which should never be done on amateur radio. We are a self-policing service/hobby and there is no way to self-police something which cannot be monitored by other hams.

Steve

[KQ6XA]

What happens when the D-Star vocoder chips are not available any longer, because the manufacturer has moved on in their production fabs toward more profitable next generation chips?

[K4JF]

Quote[/b] (ab8yy @ July 06 2007,14:58)]AS for encryption, there is no place for that on ham radio. #Period - none. #
Steve
Amen, Steve.

[w6em]

Quote[/b] (ab8yy @ July 06 2007,14:58)]We are a self-policing service/hobby and there is no way to self-police something which cannot be monitored by other hams.
Pactor II and III can only be monitored via a $1200 single source modem.....

I'd call that a form of defacto encryption....

[KE7CDV]

Quote[/b] (w6em @ July 08 2007,18:36)]
Quote[/b] ]Pactor II and III can only be monitored via a $1200 single source modem.....

I'd call that a form of defacto encryption...

That may be aggravating, but it's really not that much stronger of an argument than saying that for "full" monitoring you need an HF radio, a VHF/UHF radio, a microwave radio, at least one PC, one or more TNCs, lots of antennas, etc... There was certainly a time when monitoring something as simple as RTTY took, I imagine, more than $1200 in extra equipment once you adjust the prices of yesterday for inflation.

That being said, Pactor III is a documented protocol (even if that documentation is rather weak -- the FCC accepted it, though!), so you should certainly feel free to sit down and start building your own Pactor III modems and selling them at cost.

As mentioned previously, current rules allow authetication of users using "opaque" methods. E.g., it's perfectly OK for a packet BBS to send a "challenge" string to you, you to encrypt it using a private key, and send back the result to the BBS to prove that "you're you." Everyone can see the challenge and your response, but since the challenge will be different next time and "the real you" is (hopefully) the only one with the unique private key, it's (nearly) impossible for someone else to impersonate you on the air.

I agree with the other posters that actual encryption is very much against the spirit of amateur radio and *not* something we should be asking the FCC for.

A few more thoughts on D-Star:

-- Unfortunately, there isn't a sound card mode for D-Star because the CoDec used is proprietary with DVSI... and they want $100k for a source code license! (Whereas ICs that implement the AMBE standard are apparently reasonably priced.)
-- What happens in DVSI goes out of business and you can no longer purchase the AMBE CoDec ICs? Well... worst case, there are no more *new* D-Star radios. Big deal! This is a hobby -- if D-Star dies, it's not the end of the world. Of course, I don't think that's a very likely outcome in actuality -- the much more likely scenario is that DVSI's intellectual property is purchased by someone and AMBE lives on in some form or other.
-- As amateurs we should all support the development of 100% freely available digital modes, but until that actually happens, I see nothing wrong with paying Icom to purchase AMBE CoDecs from DVSI.

---Joel

[ka7fox]

Quote[/b] (W9WHE @ July 06 2007,14:20)]APCO P25 IS THE WORLD-WIDE STANDARD FOR DIGITAL COMMUNICATIONS. WHAT IS D-STAR?
I'd just like to point out that P25 is in no way a "world wide" standard, since most of Europe uses TETRA, and some places (still) use iDEN (which was originally a digital trunking system with phone services, not a cell phone system), and so fourth.

And by the way, capitals are harder to read than normal mixed case and generally its bad taste to write in all capitals on the internet.

Edit to add: It would be really nice if something open like Ogg Speex could be made part of something like D-STAR, so that a totally open implementation can be made.

[n1dvj]

Quote[/b] (w6em @ July 08 2007,18:36)]Pactor II and III can only be monitored via a $1200 single source modem.....

I'd call that a form of defacto encryption....
I wonder... #Is that because it's difficult to decode without a fancy DSP and some significant processor power such that no one other than the developers with a vested interest have done it or are the specs actually supressed as 'trade secret'?

If they are supressed, then how the heck are they allowed on HAM frequencies??

[wa4gch]

Quote[/b] (n1dvj @ July 09 2007,11:30)]Quote[/b] (w6em @ July 08 2007,18:36)]Pactor II and III can only be monitored via a $1200 single source modem.....

I'd call that a form of defacto encryption....
I wonder... #Is that because it's difficult to decode without a fancy DSP and some significant processor power such that no one other than the developers with a vested interest have done it or are the specs actually supressed as 'trade secret'?

If they are supressed, then how the heck are they allowed on HAM frequencies??
To hear them they are the ONLY mode on ham frequencys.

[WA9SVD]

Quote[/b] (wa6itf @ July 04 2007,10:33)]Quote[/b] (N3CRT @ July 04 2007,06:48)]Expensive radios that dont work all the time on the Satellite? No thanks I'll stick with my IC-910h. It may be expensive but it doesnt drop out.
Even with the Doppler induced drop-outs, it is a rather noble first time achievement. If anything, it shows that the terrestrial radio gear will need to be improved to that it can tune in smaller increments such as 100 Hz steps or such.

If satellite operation of D-Star become popular, then I suspect that Icom -- or some other manufacturer -- will bring out gear specific for this type of utilization. Another though far more costly solution would be to launch into geosynchronous orbit three "TDRS-like" satellites that could be linked together to permit terrestrial hams to "talk" or exchange "data" in real time from any spot on the globe to any other spot on the globe.

Right now the two biggest complaints I as a writer hear are that ham radio satellites require stations be equipped to track them and that they are not available 24 hours a day / 7 days a week. Once satellite operation comes of age to where a given terrestrial station need only have an antenna fixed to one location in the sky, I suspect that you will see many more -- if not most of the worlds radio amateurs give it a try.

Technology is ever moving forward, A good example is FM which did not come of age until the first repeaters came on the air back in the late 1960's. A decade later, almost every ham owned some sort of FM transceiver -- at least for 2 meters -- and there were some 3500 repeaters in operation in the USA. By 1990 there were about 9500 FM repeaters world-wide and growth did not level off until about 2002.

Whether or not D-Star will be a catylist that pushes the worlds various AMSAT groups to think in terms of providing the global ham radio community with a system of digital ready, interlinked geosynchronous ham radio utility communications "Easy Sats" I cannot say. Its just far to early to know. But in the big picture, this D-Star experiment -- and in reality is is just an "experiment" -- does open the "ham radio digital door" a bit wider. And is not "experimentation" that leads to "utility" really an important part of what ham radio is really all about?


de
WA6ITF
No offense, Bill,

But isn't that "Pie (satellite?) in the sky" thinking?

It's one thing to envision what amounts to a system of geostationary Amateur sats HEO (High Earth Orbit) that will provide communications to ALL users, much less D-Star (or any other digital system) users? Where will the money come from? Remember AO-40? That was an expensive way to prove Colonel Murphy was correct. But where will Amateurs come up with the funds to launch several satellites for digital use?

I would not support ANY expenditure of funds I make to AMSAT to support a satellite that would support only digital voice modes. But I would not support a satellite that excluded them, either. The digital "revolution," if it proves to be much more than a few pip squeak firecrackers rather than a full blown war, needs to prove itself further. Experimentation is fine, but at least in this point in time, it seems more an idea of "digital for the sake of digital," rather than digital actually providing any tangible advantage. It certainly has potential, but the real advantage (i.e., increased communication capability) has yet to be realized, if it truly exists.

It's wonderful that the first "D-Star" contact was made, but again, I have to question, "WHY is this actually such a big deal?" The digi-zealots tout D-Star (or other digital technology) as so far superior to analogue voice as to attempt to declare analogue signal methods extinct. Yet they have only now accomplished something that analogue technology has achieves decades ago? With limitations?
I see potential, but not at the expense of analogue users. In some ways, current digital tewchniques seem to be a solution looking for a problem, at least at this juncture.

[K9ZED]

Quote[/b] (W5HTW @ July 05 2007,18:56)]Quote[/b] (k5okc @ July 04 2007,20:00)]Quote[/b] (wb3dye @ July 04 2007,20:50)]Why aren't we using APCO Project 25 digital? #It's becoming the national standard for public safety comms.
Who cares. #Public Safety isn't ham radio.

Quote[/b] ]It could get to a point that those of us who have public safety frequencies plugged into our FM #2 meter/440 radios will be out of luck.

If you want to be a fireman or an ambulance driver, then join the force.

Quote[/b] ]If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders.

Hams should stay off Public Service frequencies. #If you want to communicate directly with first responders, have them give you a radio. #It's probably encrypted anyway.
Exactly. #Exactly! #Exactly!!! # Precisely. #Darned right.

Thanks for saying that. #If we could stop playing cop long enough to get back into ham radio, we'd have a heck of a lot more fun -- and more experimentation.


Ed
Quote[/b] ]Why aren't we using APCO Project 25 digital? It's becoming the national standard for public safety comms.
Who cares. Public Safety isn't ham radio.

Quote[/b] ]It could get to a point that those of us who have public safety frequencies plugged into our FM 2 meter/440 radios will be out of luck.

If you want to be a fireman or an ambulance driver, then join the force.

Quote[/b] ]If we were using Project 25 as a digital standard that wouldn't be a problem--especially during an "emergency" when that 2 meter/440 radio is needed to communicate directly with first responders.

Hams should stay off Public Service frequencies. If you want to communicate directly with first responders, have them give you a radio. It's probably encrypted anyway.[/quote]
Exactly. Exactly! Exactly!!! Precisely. Darned right.

Thanks for saying that. If we could stop playing cop long enough to get back into ham radio, we'd have a heck of a lot more fun -- and more experimentation.


Ed[/QUOTE]

I disagree.

I don't know why APCO Project 25 digital is not being studied.... I'd would be interested in facts about it though.

What I do know is this:

Public safety may not be Amateur Radio, but Amateur Radio has a lot of supporters, even defenders, in the Public Safety community. Much of the support Amateur Radio has comes not from its purposes as an experimental medium, but due to the perceived and real value to serve the people of this country in emergencies. While some may not care about the relationship between public safety and the Amateur Radio, it would be foolish to disparage those who do. With out the public service component, amateur radio would have a very, very difficult time holding on to spectrum.

To speak in a disparaging way about "Playing cop" or "Ambulance Drivers" seems insulting to both the Public Safety employees and the Hams who are interested in working with Public Safety employees. No one is forcing any Ham to not have fun or avoid experimentation, that is a personal choice of focus for some individuals.

BTW, Most public safety communication is not "encrypted". In fact most is, by law, public record. The use of frequency sharing trunked communications is common to optimize spectrum usage, and digital systems are coming on line to further enhance efficiency. While "Telephone" communications are protected by law, the use of TDMA, CDMA, or similar digital process in the public safety systems is for efficiency, not "security"

These of you with an interest in Public Safety go right ahead and lean how we work, and how you might fit in with planning for emergencies of all sizes.

Those who don't, keep doing what you are doing.

Each of you will be contributing knowledge that may be of value to every one of us.

[ZR4LP]

ZR4LP

In South Africa a certain Radio cost R1100 ,the DSTAR chip is R1300. More than radio.
i cant even afford to buy a HF radio,never in my life will i buy
DSTAR chip.Goodluck for those that can afford to spend the money. Johan Visagie ZR4LP