W2BRI reviews the AOR ARD9800

[w2bri]

W2BRI recently completed a review of the all new digital voice modem from AOR, the ARD9800. This device allows for digital voice over HF, VHF, in any mode or frequency. W2BRI beats the other magazines like CQ and QST with review of this new technology, sound samples from the modem, and an entire digital voice site.

Just as SSB came to replace AM for the most part, this new digital voice mode may slowly become the new everyday method of communication. Find out more at:

http://www.standpipe.com/w2bri/fastmodem/fastmodem.htm

73,

W2BRI

[w4lgh]

I went to the site and listened to the digital communications, and its much better than I thought it would be. Actually rather impressive. I am very interested in this mode, as I am interested in anything NEW with HAM radio. Need something new to get the ole HAM BLOOD flowing again!

Looks like AOR did a GREAT job!

[B] http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif WOW! Just checked out W6DMVs recording!
This is definetly the death of CW!
Richard W7MAX

[wd0ct]

Thanks for taking the time to do a great review.

I just listened to the samples provided. They remind me of my brother's digital cell phone. The sound is not pleasing to me and has a lot of the 'digital' effect, [as I guess it should??].

I'm sure digital ssb will get better with time. Playing with it is something I would like to do, but not now and not at this price. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

73,
Steve

[na4it]

Well, it is very different. And even though I like playing around with new stuff, digital voice will probably be too rich for my blood. A few things I would like to comment on, with quotes from the article:

(1) "However, this new product is not without its faults, and readers should not believe at this early stage of development digital voice is a perfected mode of operation without its own shortcomings. "

This is true of all new things, and the best idea is to wait and see before you buy spend and buy.

(2) "a switching power supply cannot be used with the product or on the radio utilized with the modem. "

Hmmm. looks like we have a problem. Switching power supplies are being used more and more by ham radio operators.

(3) "When a user presses the PTT on the their modem's microphone, a short ring is heard."

I distinctly remember that in amateur radio, we're not supposed to broadcast sounds to draw attention too us. I really believe something else should be thought up to "connect" the modems. Kind of reminds me of the old "Browning Golden Eagle" and it's "pinger".

As with all things in amateur radio, some will take to it. And that is what makes being amateur radio operators so good...we can experiment...we can operate the modes we personally like. Some like CW, some SSB, some VHF, some HF, some moon bounce. Just get in there and enjoy it!

Good Article Brian, I've been thinking for a long time that digital was the way of the future. This shows that to be true. Just think, with more CPU power, we may see 1Khz bandwidth or even less in a few yrs. Wouldn't that give LOTS more room on the HF bands, and with less QRM? Just think of a new ham in 2013 saying "QRM? What's that?"

73

Ken H>
K9FV

[N0FPE]

while I think digitial is a PART of the future. I dont think it will EVER replace analog voice on SSB. Digitial does not hold up under fading and QRN that is found on HF. Sorry but you cant get around Mother Nature!!!! If I want long haul back scatter, Long path, or contacts during a thurnderstorm someplace with in 100 miles of me I will have to use analog of some sort. Just the facts man!! Dont get fooled that digitial is a cure all!

Just my opinion of course and we all know what thats worth

Dan/N0FPE

[AB4MT]

Impressed NOT! But it is a new toy.

[w6th]

...Very interesting...

Sounds very good. #I just turn my rf gain to a minimum and sounds exactly the same. #I won't have a need for this new gadget, but sure will be of use to others.

A great asset to ham radio and looking for the elimination of the bugs. Don't toss this aside and can't wait to hear the bands active with this new gadget. I am sure it will catch on and be #successful.

# # # # # # # # # # # # # # # ...

[ke4pjw]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (na4it @ Nov. 06 2003,22:34)</td></tr><tr><td id="QUOTE">(3) "When a user presses the PTT on the their modem's microphone, a short ring is heard."

I distinctly remember that in amateur radio, we're not supposed to broadcast sounds to draw attention too us. I really believe something else should be thought up to "connect" the modems. Kind of reminds me of the old "Browning Golden Eagle" and it's "pinger".[/QUOTE]<span id='postcolor'>
I think the "ring" is the initial data header. It is not there to amuse or draw attention. It is there is sync the decoder to data that is about to be transmitted. Kinda of like the "preamble" that is sent before a POCSAG block for pagers. It kind of sounds like a two tone ring also.

[AG6NC]

Re: cost of digital. Just when I have spent all my children's inheritance on a complete station along #comes a a new fancy piece of gear! Great review, but I think I'll wait a few years when there are a least 12 people who have gone digital.
# Bill, KG6GNC #http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

[K5UJ]

I read the review and listened to the audio. #I think this has potential under some circumstances but the idea that this is going to dominate all HF voice, which is what some of the glowing praise seems to imply, is a dream in my opinion. #At the risk of sounding like Joe Negativity, this technology has some things that will have to be worked out--not just the sync problems, but the tx/rx delay--it currently just won't work in a fast roundtable where the operating involves real-time breaks and quick comments. #It also won't fly in phone contests for that same reason. #It seems like in its current form, the switch from tx to rx is difficult enough to encourage the older kind of AM geezer monolog transmissions. #

Another factor which no one seems to want to admit so I'll do it (why quit getting myself into trouble now) is social. #There is a competitive element in the hobby especially on HF. #Contests, and DX pileups basically are competitions. #On phone, brute force (being LOUD, meaning big antennas, QRO, audio processing) matters to a lot of hams. #Hams who have invested tens of thousands of dollars (and other denominations) or even hundreds of thousands in order to have dominant signals aren't interested in anything that levels the playing field. # # I think digital HF voice will be a welcome addition to the available modes and many will enjoy it but analog voice will be around for some time to come. #

Rob Atkinson
K5UJ

[KG4RUL]

Think Digital Cell Phone. #Think ABSOLUTELY NO CHALLENGE. #Think why bother with Amateur Radio at all?

Dennis #http://www.qrz.com/iB_html/non-cgi/emoticons/mad.gif

[ke4pjw]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KG4RUL @ Nov. 07 2003,22:59)</td></tr><tr><td id="QUOTE">Think Digital Cell Phone. Think ABSOLUTELY NO CHALLENGE. Think why bother with Amateur Radio at all?

Dennis http://www.qrz.com/iB_html/non-cgi/emoticons/mad.gif[/QUOTE]<span id='postcolor'>
No challenge in what, exactly? I was thinking about how hard it would be to write an encoder/decoder for this protocol using the soundcard in a computer. That's a real challenge.

By your logic, Digital Radio Monodial is not 'radio' either.

[WA7NIW]

Excellent topic. #Innovation has long been the basis of Amateur Radio. #Remember, there
once was a time when CW (Continuous Wave) was new and superceded the old and
antiquated "Spark", although both used Morse Code. Could a digital voice mode be our
salvation from BPL if something goes horribly wrong?

Of course, the issue would then be "cointerference" between the two systems.

Just for laughs though, can you imagine the look on the "pervert down the street's" face
when he sees "CQ Field Day" printed across Miss June's chest?

Dick http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

[n2obm]

A GREAT step forward! But, just as with my 'green radios', going digital with voice is a mixed blessing. Documented loss of 'planning' range for the same transmit power over VHF/UHF, skewed or chopped audio and/or total loss of audio. #For HF or 'weak signal mode', I'd rather stay analog and use my 'brain signal processing' to fill in 'lost' info. Is anybody working on a GSM style data that encorporates some type of FEC before reassembling data packets? Just not enough time to experiment.....:-( BTW, it rained today in Baghdad....chin up, head down!

[k5ahh]

---What would the digital transmission sound like if you didn't have this unit? Is it possible to listen to transmissions if you don't have this, or does it sound like listening to packet or something similar?

[kc0jez]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KG4RUL @ Nov. 08 2003,21:59)</td></tr><tr><td id="QUOTE">Think Digital Cell Phone. #Think ABSOLUTELY NO CHALLENGE. #Think why bother with Amateur Radio at all?[/QUOTE]<span id='postcolor'>
This is one of those attitudes/comments that has always befuddled me, in ham radio and in many other hobbies/technologies that I'm involved in. #So may have the "oh my gawd..it's easy now so what's the point" angle going, while everyone seems to be always striving for ways make it better, make it easier..make it more user friendly. Ham radio is just one of those things. Get rid of those automatic antenna tuners and learn to do it manually...get rid of those keyers and code programs and plug in a straight key..toss out those store bought radios and BUILD one. And for cripes sake quit trying to make anything easier or more convenient! #I just don't get it. #It's a mirror image of other technologies. I remember reading about the hubbub in the photo world when light meters hit the stores. #That's cheating. Same thing with auto focus, auto exposure, etc.. the "real" photographers considered it somehow less of an image if there was an automatic camera involved. Same thing today with digital photograhy. #No film? #It's to easy to manipulate in the computer so it can't be "real" #Sound recording technology same thing. You can be a crummy singer but with computer programs churn out CD's that sound great (believe me..Nashville has been doing that big time for 10 years). #It's like we're encouraged to come up with new stuff...perfect it..then not use it because it makes it too easy! #I personally like building, and I like radios with tubes. #I like tinkering with the innards. #I'm not amused bringing it home, plugging it in and keying it up. #I need to bond with the innards. #But that's just me. #If you like it easy and want to operate your brains out and never learn anything about the inner workings..that's fine with me. #Just seems that I hear so much the "it's too easy so what's the point" attitude in recent years.

[aa1mn]

KC0JEZ,

Isn't the whole point of technology to make our lives easier not harder?

I had a math teacher who had an attitude similar to yours. He always wanted the students to do math "the long way". Just couldn't get it through his thick skull that math, like language or any other tool, is meant to be used to improve life by making things easier not more difficult.

Ever hear the saying, "The simplist solution to a problem is usually the best"?

If you like making life harder on yourself why don't you live in a cave and cook your food over a campfire after having hunted it down with your bare hands?

Just trying to make a point.

AA1MN

[KE4MOB]

I (for one) would have liked to see (really hear) a head-to-head comparison of SSB vs. digital. It would have been nice if the reviewer would have gone from digital to SSB so we could see the propagation characteristics.

It would also have been nice to see how well the system worked with QRM and QRN, off frequency stations, and in roundtables where one station may step on another. The review as it is now, just shows us it works. How well remains to be seen...

Chuck said it best: "The simplist solution to a problem is usually the best".

CW anyone? http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

[kf4pv]

There's actually a good reason for the manual camera settings and doing math the long way. As good as the cameras are (and they are getting better every day), they still can be fooled, especially when the photographer is trying for a special effect that is not what the onboard computer is programmed for. At those times, the answer is to switch to manual. The rest of the time there's nothing wrong with automatic.

As for the math class, that's what you do in math classes - learn all the rules and whys and wherefores. If you can't do that in a math class, where will it get done? Once you've learned the principles, then it makes perfect sense to use all the shortcuts, but until you know how the shortcuts work, how do you know which ones to use and when?

Please don't get me wrong, I love my symbolic math package that evaluates triple integrals in less time than it takes me to write them out with a pencil, but if I didn't already know calculus, I'd never know if the computer was right or if was just moronically following my instructions because it doesn't know any better.

And in the same way, when conditions are right, the digital voice modes are going to be great. When the conditions aren't right, we should be ready to switch to another mode. The digital voice modes will keep getting better as hardware gets cheaper and faster and eventually they'll handle situations that would stop them cold today.

When the vast majority of voice is done on digital, there'll still be people who enjoy the older modes, and what's wrong with that? As long as we're flexible and considerate of the other ham, it won't be a problem.

73

Laszlo

[aa1mn]

KF4PV,

Valid points, there is a time and place for everything. As you so aptly pointed out, as with the example of using manual settings on an automatic camera, there are times that a little more effort is required for an improved final result and -- when the case calls for it -- I would choose this way as well.

Why, though, would one choose a more difficult method of achieving a goal when the easier one suffice just as well?

Is it understandable that I was able to use the short method of doing math because I already knew the rules?

My former math teacher was never able to concede this point and to this day, not to my surprise, he is still stuck in high school while I and many others have long since left.

I hope that no one interpreted my post as being rude for that was not the intent; it was simply meant to show that some of us taken satisfaction in using what is readily available to our best advantange just as there are those who take pride and satisfaction of doing it the "hard way".

To each his own.

AA1MN

[kw9u]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KenH @ Nov. 08 2003,05:40)</td></tr><tr><td id="QUOTE">Good Article Brian, I've been thinking for a long time that digital was the way of the future. #This shows that to be true. #Just think, with more CPU power, we may see 1Khz bandwidth or even less in a few yrs. #Wouldn't that give LOTS more room on the HF bands, and with less QRM? #Just think of a new ham in 2013 saying "QRM? #What's that?"

73

Ken H>
K9FV[/QUOTE]<span id='postcolor'>
Just answer, "High BER". #http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

[N5RLR]

<span style='color:blue'>Okay, my weigh-in on this, and forgive me if I'm "preaching to the choir"…

"This modem allows for digital voice communication over HF that's within 2.8 KHz bandwidth."

Hmm…since we’re supposed to be limited to 3 KHz bandwidth on HF (at least for SSB), the difference of 200 Hz (+/- 100 Hz either side) would seem to be "splitting hairs." One has to ask oneself, is all the extra engineering really necessary for such a small difference?

"The modem uses a form of multiplexed PSK to create ‘near FM’ voice quality."

Clarity is always good. But in this context, it is no real substitute for skill and training. The challenge of long-haul HF Amateur Radio is honing one’s skill at being able to "pluck" a signal from the ether. One part of this is through selection of equipment, antenna(s), etc. The other part is availing oneself of proper and efficient operating practices.

"This type of technology could change ham radio is a large way. Imagine getting on a band and having QSOs with none of the common noise, hash, and hiss of regular HF communication."

For those who have experienced HF, the noise often heard is "the nature of the beast." Sure, it’s no one’s friend, but a practiced, practical operator will learn (or will have learned) how to deal with it, be it through mental conditioning ("tuning out" what is not desired to be heard, a la the "cocktail party effect") or by utilizing his existing equipment to its full potential (installing filters, switching to a different antenna, etc.).

Listening to the audio clips referenced elsewhere in this thread, I have to say that while the mode is intriguing, there are some shortcomings. One which is very obvious is the ubiquitous "digital edge" to the audio; even to my diminished hearing, it doesn’t have the "warmth" of human speech that I would prefer. Another shortcoming is the dreaded "dropout" of the digital data, well know to those who’ve ever experienced a digital-cellphone call.

"When a user presses the PTT on their modem's microphone, a short ring is heard. This ring is a digital header being sent by your modem to alert other modem users on frequency that digital communication is about to be sent."

To NA4IT’s comment that we as operators are not supposed to "draw attention to ourselves" using sound effects: I believe that this ring-tone is allowed per FCC regs, as it assists in establishing communication, much like the DTMF-paging function on virtually every VHF and UHF FM rig built within the last ten years or so.

Brian, W2BRI; Charles, G4GUO; and others here have noted that this may not be the end-all/be-all/cure-all for Amateur Radio. It is a very noteworthy achievement, and as a ham-radio operator in particular, and radio-hobbyist in general, I applaud everyone who had a hand in the development of digital voice for Amateur Radio. But, I just do not feel that it is perfected yet; indeed, W2BRI has even alluded so.

For casual rag-chewing on HF, it’s a nice way to go; however, I personally wouldn’t solely depend upon it in an emergency situation, and/or with marginal propagation conditions. For local emergency operations on VHF/UHF FM; this may come in handy, especially where voice and data traffic (NTS Radiograms, etc.) could be handled simultaneously.

The death of CW? No, methinks this isn’t (and shouldn’t be) the death of anything. As radio operators, we’re supposed to be flexible, creative, innovative…anything to get the job done. That, for me, is the real challenge of Amateur Radio. Tinkering with technology is great…but, let’s leave the "operator" in the equation, shall we?

Also…let’s get back to having fun. Some of us are tired of the endless "Code-vs-No-Code" diatribes. (Sorry, I just had to throw this in…) http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif</span>

[k5okc]

I don't think enough of the details were included in many of the comments. This is basically a 2400 baud voice, with 1200 baud of FEC (3.6 kbps) which offers error correction rather than retries. It uses a state of the art DSP vocoder chip, and a very nice 32 bit CPU from Hitachi. As I begin to use my modem (#53, so there are at least 53 people out there http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif ) I'm hoping that I don't have to use my 50 year old ears to pull out a QSO, and I suspect that the protocol will work where my ears can't hear kaka. Time will tell. Thanks for the review!

[ky5u]

My favorite comment thus far was:

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">WOW! Just checked out W6DMVs recording!
This is definetly the death of CW!
Richard # #W7MAX [/QUOTE]<span id='postcolor'>

Dell just came out with a 3gHz computer, guess it is definately the end of "post it notes"!! #LOL #Chevy came out with a new truck, this is definetly the end of chicken wire!! #ROFL #Richard, pard, ....don't buy this thing. #You won't be able to get it to work. LOLOL

Sorry, I'm just pulling your leg a little. #Go ahead and get one. #They will work on CB rigs too... RFOL! #Okay, okay...sorry, I got carried away "Good Buddy!" #LOLOL There it goes again. #I hate it when that happens... sorry... #Wonder if it has a "roger beep"?? #http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

Gonna get one and hook it up to your 2M FM rig? #You'll get near FM quality digital voice if you do!!! # http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

[w6zo]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (na4it @ Nov. 07 2003,21:34)</td></tr><tr><td id="QUOTE">I distinctly remember that in amateur radio, we're not supposed to broadcast sounds to draw attention too us.[/QUOTE]<span id='postcolor'>

Huh? Just what part of the FCC rules do you remeber this from? And it isn't a "ring" like a "roger beep" - I is a data stream that causes a ring in another modem when it is synced up.

Getting slightly off topic - but is this the same rule that says we aren't supposed to call CQ on a repeater? Funny - I can't tell you how many times I have gone on a repeater and signed my call after (or before) someone has "kerchunked" it and not had a reply. But I have had a lot of enjoyable QSOs by calling CQ - just what the hell is "W6XYZ monitoring" supposed to mean anyway?

Don
W6ZO

[k5ahh]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (w6zo @ Nov. 11 2003,15:33)</td></tr><tr><td id="QUOTE">just what the hll is "W6XYZ monitoring" supposed to mean anyway?[/QUOTE]<span id='postcolor'>
http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif Hi, Don. There is a good explanation of that in "The ARRL Repeater Directory". I have the 2002/2003 edition, and on page 10, Chapter 1, Repeater Operating Practices number 2, it reads: "To initiate a contact simply indicate that you are on frequency. Various geographical areas have different practices on making yourself known, but, generally, "This is K5AHH monitoring" will suffice. " Like it read, it is different depending on where you live, but that is what the majority of us use in this area.

[K0RGR]

After hearing the demos, I'd sure like to try one! The one watt signal from W6 to W2 was quite impressive. Yes, if that was 10 meter FM on a great day, you'd have had the same thing. Maybe there were rhombics on both ends. In any case, this sounds like a very viable mode.

No, it won't be the death of SSB. You can't operate VOX on this mode, apparently. No Ahhhhhhh-peal for the 75 meter crowd. But for 'old AM-style' ragchewers like me, it looks very interesting!

From their website, it appears that AOR is working with others to help bring other compatible units onto the market. When that happens, I suspect the prices will drop. AOR forecast sharp discounts from the ham dealers which have not happened yet.

[KE4MOB]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (k5okc @ Nov. 11 2003,10:18)</td></tr><tr><td id="QUOTE">This is basically a 2400 baud voice, with 1200 baud of FEC (3.6 kbps) which offers error correction rather than retries. #[/QUOTE]<span id='postcolor'>
Uhh....how this is legal under Part 97?

For 12 meters and under, the symbol rate can't exceed 300 baud, and for 10 meters, it can't exceed 1200 baud.

I suppose if you are running multiplexed data streams (8-300 baud streams) then that would work, but wouldn't that be spread spectrum and subject to Sec 311 of Part 97?

[kw9u]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (w6zo @ Nov. 11 2003,13:33)</td></tr><tr><td id="QUOTE">Getting slightly off topic - but is this the same rule that says we aren't supposed to call CQ on a repeater? Funny - I can't tell you how many times I have gone on a repeater and signed my call after (or before) someone has "kerchunked" it and not had a reply. But I have had a lot of enjoyable QSOs by calling CQ - just what the hell is "W6XYZ monitoring" supposed to mean anyway?

Don
W6ZO[/QUOTE]<span id='postcolor'>
Maybe the "kerchunkers" don't come back to you because they don't have (or deserve) a license.

A lot of people in my area agree about the "monitoring" thing. So a lot of hams just throw out their call sign. You don't have to be exceptionally bright to know what it means.

With the channelization and clarity of FM, you don't need the CQ CQ <call> three times stuff, which basically exists to provide a signal so that a recieving station can tune to your frequency (I know you didn't do it that way, but you get the idea).

The gentlemens agreement for FM operation is supposedly to use common language instead of codes wherever possible. That's why "monitoring" or "listening" instead of "CQ". However, this is typically inconsistently applied. I've trained myself to avoid all but "73" and "QSY".
Doesn't "location" just roll off the tongue, compared to "que tee aych"?

There is a repeater etiquette guide circulating on the web, but a little KISS principle and common sense goes a long way.

What gets me, is that I've had people *answer* me with "W9XYZ monitoring". Whassa matta? You don't want a QSO?

Since you have me going here, how about the "W9XYZ clear", about 30 seconds after "W9XYZ monitoring". Like, as if just because they're monitoring, they own the frequency until they release it? This only makes sense after a station-station call, like "K9XYZ from W9XYZ".

Or how about hearing "W9XYZ QRT" five minutes after I turn on the radio. Arrggh! If you're leaving, why should I care?

Or, "...mobile 9". Bub, it's at least 800 miles to the next call district. I know what district you're in (you're not on HF).

So, put out your call, and keep on enjoying those QSO's. One more plug - once in a while, call on 146.520.

[KG4PZZ]

The whole concept seems great, but I have to wonder, when you get 100 of these little buggers all going at once and beeping and booping all over the place in a pile-up, what do you hear? Just digital tones? Scrambled words?

What about the poor guy that leaves his radio -- and PTT -- on while when he walks away from his radio? Ever been on 20 or 15 meters and heard somebody in the living room watching TV or eating dinner or vacuuming or something? You can tune that out in your head, it's not all that loud. Digital though, it would take up all 3 kHz ... er uh... 2.8. And how important is frequency stability? Off by 200 hertz or so and it goes dead / digital noise? Or do you get that funky sideband "off frequency" tone to their voice?

Will it be nice? Absolutely. I think it could make rag chewing quite enjoyable, actually. Will it replace side band? Well, I hate to be one of these old farts (especially only being 16), but there's something magical about using that DSP filter between my ears to pull a signal out of the mud. FM / "near FM" just takes all the fun away :-D... The real thing holding a lot back is probably sticker shock. $500 (or so) to get started? And we don't even know if this stuff is gonna work? Sounds like the same reason nobody is on 220, 902, or few are running those "black box" computer-controlled radios.

I like twisting knobs and pushing buttons to get stuff to work. From what I'm reading, a lot of people agree.

Just a few rambling thoughts...
Fred
KG4PZZ

[k5okc]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KE4MOB @ Nov. 12 2003,00:12)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (k5okc @ Nov. 11 2003,10:18)</td></tr><tr><td id="QUOTE">This is basically a 2400 baud voice, with 1200 baud of FEC (3.6 kbps) which offers error correction rather than retries. #[/QUOTE]<span id='postcolor'>
Uhh....how this is legal under Part 97?

For 12 meters and under, the symbol rate can't exceed 300 baud, and for 10 meters, it can't exceed 1200 baud.

I suppose if you are running multiplexed data streams (8-300 baud streams) then that would work, but wouldn't that be spread spectrum and subject to Sec 311 of Part 97?[/QUOTE]<span id='postcolor'>
Yes, legal. Symbol rate is 20ms (50 baud) times 36 carriers is 1800 baud times 2 (quadrature) is 3600 effective.



Check my math! http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

[k5okc]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KG4PZZ @ Nov. 12 2003,11:02)</td></tr><tr><td id="QUOTE">The whole concept seems great, but I have to wonder, when you get 100 of these little buggers all going at once and beeping and booping all over the place in a pile-up, what do you hear? #Just digital tones? #Scrambled words?

What about the poor guy that leaves his radio -- and PTT -- on while when he walks away from his radio? #Ever been on 20 or 15 meters and heard somebody in the living room watching TV or eating dinner or vacuuming or something? #You can tune that out in your head, it's not all that loud. #Digital though, it would take up all 3 kHz ... er uh... 2.8. #And how important is frequency stability? #Off by 200 hertz or so and it goes dead / digital noise? #Or do you get that funky sideband "off frequency" tone to their voice?

Will it be nice? #Absolutely. #I think it could make rag chewing quite enjoyable, actually. #Will it replace side band? #Well, I hate to be one of these old farts (especially only being 16), but there's something magical about using that DSP filter between my ears to pull a signal out of the mud. #FM / "near FM" just takes all the fun away :-D... #The real thing holding a lot back is probably sticker shock. #$500 (or so) to get started? #And we don't even know if this stuff is gonna work? #Sounds like the same reason nobody is on 220, 902, or few are running those "black box" computer-controlled radios.

I like twisting knobs and pushing buttons to get stuff to work. #From what I'm reading, a lot of people agree.

Just a few rambling thoughts...
Fred
KG4PZZ[/QUOTE]<span id='postcolor'>
These things have zero use in analog contests of jamming your signal amonst 75 other gomers, and blasting through the competition to become an official paper-hanger.



One thing to remember, is that this modem and a $500 sideband generator (software defined radio) will replace the multi-thousand dollar contest radios that rag-chewers don't need, and can't afford either.



PSK won't replace CW, and Vocoders won't replace SSB, but both CW and SSB will continue to attract people who want to enjoy what their grandfathers enjoyed, and roll around in the nostalgia.

Steve, K5OKC
Oklahoma City

[kw9u]

If we do get digital voice, I sure hope it's not proprietary... but it could easily go that way. Imagine having to pay a license fee to build or sell a radio.

[n0vty]

$500 price tag?
why not just use a computer with a decent sound card, oops there goes profits!

[k5okc]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (n0vty @ Nov. 29 2003,06:49)</td></tr><tr><td id="QUOTE">$500 price tag?
why not just use a computer with a decent sound card, oops there goes profits![/QUOTE]<span id='postcolor'>
Two sound cards 1) vocoder 2) OFDM modem

Please send me your 16 bit 2400 bps vocoder algorithm for the soundcard, I want to try it out. Thanks.

[skallal]

I like it. But why buy an outboard box? I use my PC soundcard for PSK31 and MFSK16. Why can't somebody write some software to utiltize the PC soundcard to do digital voice. Of course, the protocols would have to be compatible with the AOR box. In the long run, an outboard box is better, but for those of us who don't want to invest in one right now, a soundcard solution would be ideal.

Steve N6VL