Re: [DSTAR_DIGITAL] Re: Bit Rate?
Scott: Yep, fine equipment can do wonderful things (the added dynamic range at 24 bit can be spectacular), but I rarely connect my IC-92AD to my Klipsch Forte II speakers. :) Chuck On 9/2/2010 9:12 PM, ZL1CHM wrote: I work in pro audio and can hear the difference in 16bit and 24bit. audio
RE: [DSTAR_DIGITAL] Re: Bit Rate?
Probably have a drive level problem Chuck with an IC-92 directly driving audio to those Fortes anyhow‼‼‼ Thanks…Joe / W8SS / Mesh Engineering / Trustee Sysop on D-Star for K8LCD AKA: Dr. Joe Mesh, D.M.D., C.A.G.S. (Prosthodontics) from beautiful downtown HELL, Michigan Always available at: i...@drsmesh.com ... See us on the web at: W8SS, W8SSS K8LCD all on QRZ.com and at drsmesh.com From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of Charles Scott Sent: Saturday, September 04, 2010 11:38 AM To: dstar_digital@yahoogroups.com Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? Scott: Yep, fine equipment can do wonderful things (the added dynamic range at 24 bit can be spectacular), but I rarely connect my IC-92AD to my Klipsch Forte II speakers. :) Chuck On 9/2/2010 9:12 PM, ZL1CHM wrote: I work in pro audio and can hear the difference in 16bit and 24bit. audio
Re: [DSTAR_DIGITAL] Re: Bit Rate?
Jim: I am first and foremost a CW op. Will always be such. That said, it is ALL fun and a learning experience. See: http://www.qrz.com/db/wb2mic 73, Jozef WB2MIC On 9/2/2010 23 45 Hours, J. Moen wrote: Jozef, I appreciate where you are coming from. I must say that while I enjoy D-Star and my internet-connected HotSpot, probably my favoriate activity is to take a small case with my Yaesu FT-817ND and my NUE-PSK PSK modem, along with a small, light 12v battery and a small portable vertical and go out to the fields and set up. Now when I talk to people all over the US with my 3 watts and absolutely no infrastructure, including the power company, I really like that. Both SSB and PSK in this mode are sweet. Well, I must admit to some infrastructure to charge the battery, though I have it on my wish list to get a portable solar panel for charging it. With that, I could go for months without leveraging other resources for communications. Now, when I'm home, I will sometimes crank up to about 600 watts with my modern stuff, or about 400 watts with my 1960 CE 100V with 1955 CE 600L and 1955 75A4. I'll also use the power company's electricity, and I'll even hook into the internet with my D-Star gmsk node adapter HotSpot. There is no one better way to ham, no one best mode. There is only what each of enjoys doing at some particular point in time. With any kind of luck, we learn and grow, but coming back to the wonderful old stuff is fun too. Jim - K6Jm - Original Message - *From:* Jozef mailto:jo...@metaphoria.org *To:* dstar_digital@yahoogroups.com mailto:dstar_digital@yahoogroups.com *Sent:* Thursday, September 02, 2010 1:44 AM *Subject:* Re: [DSTAR_DIGITAL] Re: Bit Rate? D-Star, to me, will NEVER EVER, replace HF/SSB/CW and the thrill and romance of being able to communicate with another human being without any corporate infrastructure in-between. To give that up would be to surrender to those that control the infrastructure. I am not about to that, nor ever. D-Star is fun, fascinating, and useful. I like it. That said, there will be that nag that always irritates about it that says I am beholden to non-RF means to communicate. That is the nature of the D-Star phenomenon. So, I will put up with the QRM and the QRN and make those QSOs that actually require operator skill. For me, that is what defines ham radio. D-Star just slightly refines it, and, degrades it at the same time. JOzef attachment: jozef.vcf
Re: [DSTAR_DIGITAL] Re: Bit Rate?
I work in pro audio and can hear the difference in 16bit and 24bit. audio Saying that, I also think 28bit would be overkill being CD audio is only 16bit. Perhaps what was meant was 28kbps as in mp3 audio 73 Scott zl1chm / n0hok - Original Message - From: Joel Koltner zapwire-gro...@yahoo.com To: dstar_digital@yahoogroups.com Sent: Friday, September 03, 2010 3:49 AM Subject: [DSTAR_DIGITAL] Re: Bit Rate? --- In dstar_digital@yahoogroups.com, Charles Scott csc...@... wrote: For voice communications, 28 bits would be beyond overkill. Even for music, while someone might put up a point-to-point microwave link or similar that happens to have that level of fidelity, I don't think there's any commercial music broadcast system in the world that comes anywhere close to that sort of SNR -- assuming levels and mixing have been done properly, there's no human being on the planet who can discern the difference between 28-bit music and 24- or 20-bit... and darned few who could even tell the difference at 16 bits! __ Information from ESET NOD32 Antivirus, version of virus signature database 5419 (20100902) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5419 (20100902) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __ Information from ESET NOD32 Antivirus, version of virus signature database 5421 (20100903) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
Hello Jim. Quite agree with all you say. Plus: the D-Star system I have now allows me to sit in the garden with a handheld running 100mW and speaking to someone AND being able to understand them, on the other side of the world. Yes I could fire up HF battle through the QRM, QRN and idiots and do the same thing but it's nice to have the option. The other thing that gives D-Star the green light is my wife thinks it's cool and she's not impressed with any other branch of the hobby. Thursday, September 2, 2010, 6:50:55 AM, you wrote: JM There is a lot of room in our hobby for many niche interests and JM points of view. I became a Ham in the late 1950s and while I JM started out on AM, I switched to SSB fairly soon after. I have JM always liked communications quality audio for voice JM communications. When I discovered a whole subculture of Hams JM interested in Extended SSB, I had trouble understanding why. I JM listen to some people with carefully adjusted equalizers that JM sound like they are transmitting from their bathroom, what with JM echos etc. But then I realized that as long as they don't hog the JM bandwidth when a band is busy, there is nothing wrong with them JM wanting something more than communications quality. JM JM I just expect them to respect my preference for narrower audio response over RF. JM JM I am thinking D-Star will probably not work out for John, and JM he'll decide to move on to other parts of Ham radio. Or he'll get JM involved in experimentation with other types of digital radio that JM may involve other vocoders and different design parameters (I JM wonder what Codec2 sounds like?). And if we all live long enough, JM we will probably see other DV standards evolve. I like to think JM that if we left the planet and came back in 50 years, the vast JM majority of Ham transmissions will be some form of digital. It's JM inevitable. For John's sake, let's hope he has some audio quality choices. JM JM In the meantime, I like D-Star audio just fine, since I'm able to JM understand what everyone is saying. JM JMJim - K6JM -- Best regards, JohnG8KVPmailto:k...@bigfoot.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
D-Star, to me, will NEVER EVER, replace HF/SSB/CW and the thrill and romance of being able to communicate with another human being without any corporate infrastructure in-between. To give that up would be to surrender to those that control the infrastructure. I am not about to that, nor ever. D-Star is fun, fascinating, and useful. I like it. That said, there will be that nag that always irritates about it that says I am beholden to non-RF means to communicate. That is the nature of the D-Star phenomenon. So, I will put up with the QRM and the QRN and make those QSOs that actually require operator skill. For me, that is what defines ham radio. D-Star just slightly refines it, and, degrades it at the same time. JOzef On 9/2/2010 02 50 Hours, John Parkins wrote: Hello Jim. Quite agree with all you say. Plus: the D-Star system I have now allows me to sit in the garden with a handheld running 100mW and speaking to someone AND being able to understand them, on the other side of the world. Yes I could fire up HF battle through the QRM, QRN and idiots and do the same thing but it's nice to have the option. The other thing that gives D-Star the green light is my wife thinks it's cool and she's not impressed with any other branch of the hobby. Thursday, September 2, 2010, 6:50:55 AM, you wrote: JM There is a lot of room in our hobby for many niche interests and JM points of view. I became a Ham in the late 1950s and while I JM started out on AM, I switched to SSB fairly soon after. I have JM always liked communications quality audio for voice JM communications. When I discovered a whole subculture of Hams JM interested in Extended SSB, I had trouble understanding why. I JM listen to some people with carefully adjusted equalizers that JM sound like they are transmitting from their bathroom, what with JM echos etc. But then I realized that as long as they don't hog the JM bandwidth when a band is busy, there is nothing wrong with them JM wanting something more than communications quality. JM JM I just expect them to respect my preference for narrower audio response over RF. JM JM I am thinking D-Star will probably not work out for John, and JM he'll decide to move on to other parts of Ham radio. Or he'll get JM involved in experimentation with other types of digital radio that JM may involve other vocoders and different design parameters (I JM wonder what Codec2 sounds like?). And if we all live long enough, JM we will probably see other DV standards evolve. I like to think JM that if we left the planet and came back in 50 years, the vast JM majority of Ham transmissions will be some form of digital. It's JM inevitable. For John's sake, let's hope he has some audio quality choices. JM JM In the meantime, I like D-Star audio just fine, since I'm able to JM understand what everyone is saying. JM JM Jim - K6JM -- Best regards, John G8KVP mailto:k...@bigfoot.com mailto:kvp%40bigfoot.com attachment: jozef.vcf
Re: [DSTAR_DIGITAL] Re: Bit Rate?
There are other codecs and vocoders that provide better audio reproduction than AMBE. That's just a fact of life. There are some (EMBE) with worse characteristics. I do not enjoy using P25 for this reason, either in Amateur or public safety service. (In fact, I believe the poor audio reproduction of EMBE, coupled with its inherent lack of ambient audio noise immunity make it dangerous for public safety, too). I, too, suspect John won't stick with D-Star. That's too bad: There's a lot of development going on, and hi could likely find a home in improving things where we really can make changes. But the points made about interoperability are important. The vocoder used in D-STar isn't my favorite, but it IS burned in stone. Somewhere down the road someone will cobble up a software AMBE clone and offer it up and then we'll have a more configurable system, but even there, if we tweak the vocoder bit rate, it will no longer interoperate. When that happens, we'll have smething based on D-Star but it won't be D-Star. There are other aspects of Ham Radio to investigate and enjoy. I've wandered through Skywarn, microwave communications and antennas, HF and higher antennas, and 802.11 networking among other things. I still find ways to become excited by Ham radio. My current thing is D-Star, and while I'm not writing code for it, I've got a pretty good grasp of what it does, why, and how. And, I don't always agree with the why or how! What I don't have, however, is John's professional audio experience. If I did, I might have a similar opinion, that we could crank up the sampling and decoding rates and improve the audio. Since I do know something about how things work (and since I've looked at the networking side of D-Star), I respectfully disagree with John about how simple it'd be to enhance the audio. Sorry, it's not how things work on the startship. 73 gerry n5jxs J. Moen wrote: There is a lot of room in our hobby for many niche interests and points of view. I became a Ham in the late 1950s and while I started out on AM, I switched to SSB fairly soon after. I have always liked communications quality audio for voice communications. When I discovered a whole subculture of Hams interested in Extended SSB, I had trouble understanding why. I listen to some people with carefully adjusted equalizers that sound like they are transmitting from their bathroom, what with echos etc. But then I realized that as long as they don't hog the bandwidth when a band is busy, there is nothing wrong with them wanting something more than communications quality. I just expect them to respect my preference for narrower audio response over RF. I am thinking D-Star will probably not work out for John, and he'll decide to move on to other parts of Ham radio. Or he'll get involved in experimentation with other types of digital radio that may involve other vocoders and different design parameters (I wonder what Codec2 sounds like?). And if we all live long enough, we will probably see other DV standards evolve. I like to think that if we left the planet and came back in 50 years, the vast majority of Ham transmissions will be some form of digital. It's inevitable. For John's sake, let's hope he has some audio quality choices. In the meantime, I like D-Star audio just fine, since I'm able to understand what everyone is saying. Jim - K6JM - Original Message - *From:* n2gyn mailto:li...@gmx.net *To:* dstar_digital@yahoogroups.com mailto:dstar_digital@yahoogroups.com *Sent:* Wednesday, September 01, 2010 3:19 PM *Subject:* [DSTAR_DIGITAL] Re: Bit Rate? It's NOT a microphone issue. It's the small bit processing. I have been in Pro sound for most of my life. Their is NO WAY to get any quality at 8bit. This is unexceptionable to me! I rather listen to all the QRM and QRN in the world with analog. I am very surprise that their are not more people that feel this way. The bit rate has to be at lest 28bit to starting sounding acceptable. John -- Gerry Creager -- gerry.crea...@tamu.edu Texas Mesonet -- AATLT, Texas AM University Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983 Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843 Please TRIM your replies or set your email program not to include the original message in reply unless needed for clarity. ThanksYahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/dstar_digital/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/dstar_digital/join (Yahoo! ID required) * To change settings via email: dstar_digital-dig...@yahoogroups.com dstar_digital-fullfeatu...@yahoogroups.com * To unsubscribe from this group,
RE: [DSTAR_DIGITAL] Re: Bit Rate?
Don - Initially I agreed with your wife! Things have changed significantly in the last three years. Largely it depends which reflectors one monitors... Thanks.Joe / W8SS / Mesh Engineering / 810-629-5500 AKA: Dr. Joe Mesh, D.M.D., C.A.G.S. (Prosthodontics) from beautiful downtown HELL, Michigan Always available at: i...@drsmesh.com See us on the Web at:drsmesh.com From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of Donald James Sent: Thursday, September 02, 2010 8:35 AM To: dstar_digital@yahoogroups.com Subject: RE: [DSTAR_DIGITAL] Re: Bit Rate? This is funny! My wife is clearly a D-Star supporter as well. She's commented that she finds the exchanges more serious and technical and that it doesn't sound like a CB. And I too like using my 92AD on just 100mw and catching up with and staying in touch with friends in other cities and countries while I'm sitting on the couch, the back yard or in my office. These and several other things about D-Star make it very interesting and exciting for me. Donald ~ N2VU -Original Message- From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of John Parkins Sent: Thursday, September 02, 2010 2:51 AM To: J. Moen Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? Hello Jim. Quite agree with all you say. Plus: the D-Star system I have now allows me to sit in the garden with a handheld running 100mW and speaking to someone AND being able to understand them, on the other side of the world. Yes I could fire up HF battle through the QRM, QRN and idiots and do the same thing but it's nice to have the option. The other thing that gives D-Star the green light is my wife thinks it's cool and she's not impressed with any other branch of the hobby.
RE: [DSTAR_DIGITAL] Re: Bit Rate?
Joe, Elabourate, what are your observations, reflections can be good. Donald ~ N2VU -Original Message- From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of Dr. Joeseph Mesh Sent: Thursday, September 02, 2010 9:25 AM To: dstar_digital@yahoogroups.com Subject: RE: [DSTAR_DIGITAL] Re: Bit Rate? Don - Initially I agreed with your wife! Things have changed significantly in the last three years. Largely it depends which reflectors one monitors... Thanks.Joe / W8SS / Mesh Engineering / 810-629-5500 AKA: Dr. Joe Mesh, D.M.D., C.A.G.S. (Prosthodontics) from beautiful downtown HELL, Michigan Always available at: i...@drsmesh.com See us on the Web at:drsmesh.com From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of Donald James Sent: Thursday, September 02, 2010 8:35 AM To: dstar_digital@yahoogroups.com Subject: RE: [DSTAR_DIGITAL] Re: Bit Rate? This is funny! My wife is clearly a D-Star supporter as well. She's commented that she finds the exchanges more serious and technical and that it doesn't sound like a CB. And I too like using my 92AD on just 100mw and catching up with and staying in touch with friends in other cities and countries while I'm sitting on the couch, the back yard or in my office. These and several other things about D-Star make it very interesting and exciting for me. Donald ~ N2VU -Original Message- From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of John Parkins Sent: Thursday, September 02, 2010 2:51 AM To: J. Moen Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? Hello Jim. Quite agree with all you say. Plus: the D-Star system I have now allows me to sit in the garden with a handheld running 100mW and speaking to someone AND being able to understand them, on the other side of the world. Yes I could fire up HF battle through the QRM, QRN and idiots and do the same thing but it's nice to have the option. The other thing that gives D-Star the green light is my wife thinks it's cool and she's not impressed with any other branch of the hobby.
RE: [DSTAR_DIGITAL] Re: Bit Rate?
Some respond to the challenge of acquiring the knowledge required to accomplish a remarkable feat of great distance and low power on HF... Others like it handed to them effortlessly with fidelity Which side one agrees with is a personal issue. Some say real men use their heads and learn to achieve on their own without the net - then they take great pride in the resulting accomplishment.The endorphins released are addicting to those. Others enjoy jumping on the new tech - sit back and relax - approach For me the excitement in D-Star resides in the improvement in DX mobile communications. In even the very best situation D-Star will NEVER reflect the magnitude of personal accomplishment seen on HF SSB in real radio relying on RF and knowledge... I got a QSL card today from Europe via D-Star... OK... But of what value is the signal report and distance? Just different Little more. Thanks.Joe / W8SS / Mesh Engineering / Trustee Sysop on D-Star for K8LCD AKA: Dr. Joe Mesh, D.M.D., C.A.G.S. (Prosthodontics) from beautiful downtown HELL, Michigan Always available at: i...@drsmesh.com ... See us on the web at: W8SS, W8SSS K8LCD all on QRZ.com and at drsmesh.com From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of John Parkins Sent: Thursday, September 02, 2010 2:51 AM To: J. Moen Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? Hello Jim. Quite agree with all you say. Plus: the D-Star system I have now allows me to sit in the garden with a handheld running 100mW and speaking to someone AND being able to understand them, on the other side of the world. Yes I could fire up HF battle through the QRM, QRN and idiots and do the same thing but it's nice to have the option. The other thing that gives D-Star the green light is my wife thinks it's cool and she's not impressed with any other branch of the hobby. Thursday, September 2, 2010, 6:50:55 AM, you wrote: JM There is a lot of room in our hobby for many niche interests and JM points of view. I became a Ham in the late 1950s and while I JM started out on AM, I switched to SSB fairly soon after. I have JM always liked communications quality audio for voice JM communications. When I discovered a whole subculture of Hams JM interested in Extended SSB, I had trouble understanding why. I JM listen to some people with carefully adjusted equalizers that JM sound like they are transmitting from their bathroom, what with JM echos etc. But then I realized that as long as they don't hog the JM bandwidth when a band is busy, there is nothing wrong with them JM wanting something more than communications quality. JM JM I just expect them to respect my preference for narrower audio response over RF. JM JM I am thinking D-Star will probably not work out for John, and JM he'll decide to move on to other parts of Ham radio. Or he'll get JM involved in experimentation with other types of digital radio that JM may involve other vocoders and different design parameters (I JM wonder what Codec2 sounds like?). And if we all live long enough, JM we will probably see other DV standards evolve. I like to think JM that if we left the planet and came back in 50 years, the vast JM majority of Ham transmissions will be some form of digital. It's JM inevitable. For John's sake, let's hope he has some audio quality choices. JM JM In the meantime, I like D-Star audio just fine, since I'm able to JM understand what everyone is saying. JM JM Jim - K6JM -- Best regards, John G8KVP mailto:k...@bigfoot.com mailto:kvp%40bigfoot.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
Like fishing - it's not necessarily how big the bites are, but how fast they are biting - a combination of sample size and rate - seems like there is a rule that sample rate must be twice the highest frequency being digitized - for me the test would be with or without hearing aids. steve On Thu, Sep 2, 2010 at 10:49 AM, Joel Koltner zapwire-gro...@yahoo.comwrote: --- In dstar_digital@yahoogroups.com, Charles Scott csc...@... wrote: For voice communications, 28 bits would be beyond overkill. Wet birds never fly at night.
Re: [DSTAR_DIGITAL] Re: Bit Rate?
Hello Jozef, Read the post. No where did I say I would give up HF in favour of D-Star, I said it's nice to have the option of either. When I want to sit in the garden and have a beer and a chat with someone on the other side of the world D-Star is the way to go. When I want to work DX then I go to the shack, fire up HF, put down the beer and concentrate. Thursday, September 2, 2010, 9:44:59 AM, you wrote: J D-Star, to me, will NEVER EVER, replace HF/SSB/CW and the thrill and J romance of being able to communicate with another human being without J any corporate infrastructure in-between. To give that up would be to J surrender to those that control the infrastructure. I am not about to J that, nor ever. D-Star is fun, fascinating, and useful. I like it. That J said, there will be that nag that always irritates about it that says I J am beholden to non-RF means to communicate. That is the nature of the J D-Star phenomenon. So, I will put up with the QRM and the QRN and make J those QSOs that actually require operator skill. For me, that is what J defines ham radio. D-Star just slightly refines it, and, degrades it at J the same time. J JOzef -- Best regards, Johnmailto:k...@bigfoot.com Please TRIM your replies or set your email program not to include the original message in reply unless needed for clarity. ThanksYahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/dstar_digital/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/dstar_digital/join (Yahoo! ID required) * To change settings via email: dstar_digital-dig...@yahoogroups.com dstar_digital-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: dstar_digital-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On Sep 2, 2010, at 9:17 AM, Steve Bosshard (NU5D) wrote: Like fishing - it's not necessarily how big the bites are, but how fast they are biting - a combination of sample size and rate - seems like there is a rule that sample rate must be twice the highest frequency being digitized - for me the test would be with or without hearing aids. steve On Thu, Sep 2, 2010 at 10:49 AM, Joel Koltner zapwire-gro...@yahoo.com wrote: --- In dstar_digital@yahoogroups.com, Charles Scott csc...@... wrote: For voice communications, 28 bits would be beyond overkill. Wet birds never fly at night. AMBE beats the Nyquist-Shannon sampling theorem by not just simply sampling the audio. It takes pre-sampled audio (say 8 KHz. sample rate), analyzes it, and sends a series of codes that characterize the original waveform but throws away the whole original samples. On the receive end the AMBE algorithm uses those codes to totally synthesize a new wave form that mathematically approximates the original waveform. That is why we can get communications quality audio in 2400 bps (or possibly 1200 bps in their newer low rate (LR) chips). So the Analog to Digital is going to be something like 8000 samples per second, but what the AMBE chip outputs is totally different and at 2400 bps (plus FEC). A short explanation of sampling rates can be found at http://en.wikipedia.org/wiki/Sampling_rate Interestingly, when I was in the Air Force (1980-1984) I worked on a project for digitized imaging and in pure grayscale 5-bits was about all a human could discern. John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
Re: [DSTAR_DIGITAL] Re: Bit Rate?
No where did I imply that you said you would give up HF. :) Differing aspects of amateur radio have their place. That's what makes it, in my opinion, the hobby I never grow tired of. Been pounding brass for almost 47 years now. CW will still be here 47 more years from now. D-Star will most likely yield to something else - which fine and dandy. CU on 160 this winter. 73, Jozef WB2MIC On 9/2/2010 12 32 Hours, John Parkins wrote: Hello Jozef, Read the post. No where did I say I would give up HF in favour of D-Star, I said it's nice to have the option of either. When I want to sit in the garden and have a beer and a chat with someone on the other side of the world D-Star is the way to go. When I want to work DX then I go to the shack, fire up HF, put down the beer and concentrate. Thursday, September 2, 2010, 9:44:59 AM, you wrote: JD-Star, to me, will NEVER EVER, replace HF/SSB/CW and the thrill and J romance of being able to communicate with another human being without J any corporate infrastructure in-between. To give that up would be to J surrender to those that control the infrastructure. I am not about to J that, nor ever. D-Star is fun, fascinating, and useful. I like it. That J said, there will be that nag that always irritates about it that says I J am beholden to non-RF means to communicate. That is the nature of the J D-Star phenomenon. So, I will put up with the QRM and the QRN and make J those QSOs that actually require operator skill. For me, that is what J defines ham radio. D-Star just slightly refines it, and, degrades it at J the same time. J JOzef attachment: jozef.vcf
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On Sep 2, 2010, at 9:17 AM, Steve Bosshard (NU5D) wrote: Like fishing - it's not necessarily how big the bites are, but how fast they are biting - a combination of sample size and rate - seems like there is a rule that sample rate must be twice the highest frequency being digitized - for me the test would be with or without hearing aids. steve On Thu, Sep 2, 2010 at 10:49 AM, Joel Koltner zapwire-gro...@yahoo.com wrote: --- In dstar_digital@yahoogroups.com, Charles Scott csc...@... wrote: For voice communications, 28 bits would be beyond overkill. Wet birds never fly at night. AMBE beats the Nyquist-Shannon sampling theorem by not just simply sampling the audio. It takes pre-sampled audio (say 8 KHz. sample rate), analyzes it, and sends a series of codes that characterize the original waveform but throws away the whole original samples. On the receive end the AMBE algorithm uses those codes to totally synthesize a new wave form that mathematically approximates the original waveform. That is why we can get communications quality audio in 2400 bps (or possibly 1200 bps in their newer low rate (LR) chips). So the Analog to Digital is going to be something like 8000 samples per second, but what the AMBE chip outputs is totally different and at 2400 bps (plus FEC). A short explanation of sampling rates can be found at http://en.wikipedia.org/wiki/Sampling_rate Interestingly, when I was in the Air Force (1980-1984) I worked on a project for digitized imaging and in pure grayscale 5-bits was about all a human could discern. John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On Sep 2, 2010, at 6:36 AM, Dr. Joeseph Mesh wrote: Some respond to the challenge of acquiring the “knowledge required” to accomplish a remarkable feat of great distance and low power on HF... Others like it handed to them effortlessly with fidelity Which side one agrees with is a personal issue. Some say “real men” use their heads and learn to achieve on their own without the net - then they take great pride in the resulting accomplishment.The endorphins released are addicting to those. Others enjoy jumping on the “new tech” - sit back and relax - approach For me the excitement in D-Star resides in the improvement in DX mobile communications. In even the very best situation D-Star will NEVER reflect the magnitude of personal accomplishment seen on HF SSB in “real radio” relying on RF and knowledge... I got a QSL card today from Europe via D-Star... OK... But of what value is the signal report and distance? Just different Little more. Don't forget, the infrastructure of D-STAR is useful, but there is such a thing as simplex D-STAR with all the challenges and rewards as any other RF based communications. On VHF/UHF we can see who is able to get EME D-STAR, on HF we can see who sets new mode DX (IC-9100 does 10 meters, but in some parts of the world there are fewer mode restrictions and even the US rules seem to allow for Phone in bandwidth and modulation index of D-STAR on other HF bands - and some hams have tried it http://www.youtube.com/watch?v=zlIqpedYsYM ) John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On 9/2/2010 3:30 PM, n2gyn wrote: Well, I thank everyone for their comments and Technical info. I think because of my trained ear it makes it harder to deal with the robot sound. It reminds me of effects processing. One thing that puzzles me is, why some stations sound less robotic then others. Why is that?? I am not looking for HIFI sound quality, just a more natural sound. I feel like I am talking to a computer instead of a real person. Very impersonal. Thanks to all again for your comments. John My experience is that most D-STAR stations do not sound like robots. It is not the pure note of analog, but certainly quite smooth and clear. Perhaps you have some multipath, or other issue that is causing a just enough bit errors that the AMBE chip is not quite able to correct them all. Have you been able to try D-STAR simplex on a short and clear path? -- John D. Hays Amateur Radio Station K7VE http://k7ve.org PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org sip:j...@hays.org mailto:j...@hays.org
Re: [DSTAR_DIGITAL] Re: Bit Rate?
Jozef, I appreciate where you are coming from. I must say that while I enjoy D-Star and my internet-connected HotSpot, probably my favoriate activity is to take a small case with my Yaesu FT-817ND and my NUE-PSK PSK modem, along with a small, light 12v battery and a small portable vertical and go out to the fields and set up. Now when I talk to people all over the US with my 3 watts and absolutely no infrastructure, including the power company, I really like that. Both SSB and PSK in this mode are sweet. Well, I must admit to some infrastructure to charge the battery, though I have it on my wish list to get a portable solar panel for charging it. With that, I could go for months without leveraging other resources for communications. Now, when I'm home, I will sometimes crank up to about 600 watts with my modern stuff, or about 400 watts with my 1960 CE 100V with 1955 CE 600L and 1955 75A4. I'll also use the power company's electricity, and I'll even hook into the internet with my D-Star gmsk node adapter HotSpot. There is no one better way to ham, no one best mode. There is only what each of enjoys doing at some particular point in time. With any kind of luck, we learn and grow, but coming back to the wonderful old stuff is fun too. Jim - K6Jm - Original Message - From: Jozef To: dstar_digital@yahoogroups.com Sent: Thursday, September 02, 2010 1:44 AM Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? D-Star, to me, will NEVER EVER, replace HF/SSB/CW and the thrill and romance of being able to communicate with another human being without any corporate infrastructure in-between. To give that up would be to surrender to those that control the infrastructure. I am not about to that, nor ever. D-Star is fun, fascinating, and useful. I like it. That said, there will be that nag that always irritates about it that says I am beholden to non-RF means to communicate. That is the nature of the D-Star phenomenon. So, I will put up with the QRM and the QRN and make those QSOs that actually require operator skill. For me, that is what defines ham radio. D-Star just slightly refines it, and, degrades it at the same time. JOzef
Re: [DSTAR_DIGITAL] Re: Bit Rate?
If you change the vocoder, doesn't that mean that everyone else will have to as well, or else you will be off by your lonesome ? But I may be wrong...steve n2gyn wrote: Thank you all for you reply and comments. -- Ham Radio Spoken Here !!! EM11ma - South Mountain, Texas
RE: [DSTAR_DIGITAL] Re: Bit Rate?
There are likely two possible areas for improvement and one where improvement is likely impossible. Some radios seem to have better transmit audio than others. Many people find the IC-2200 very good while many people find the ID-880 very bad. Possible the receive audio could also be improved by some additional audio processing. Much of the poor quality in DStar can be attributed to the AMBE Vocoder. This is a very complex algorythm that converts a high bit-rate voice data stream into a very low bit-rate data stream. By its very nature this is a lossy process. Removing bits must reduce the information content of the data. AMBE attempts to maximize the bit-rate while maintaining 'acceptable' audio quality. Some people may find the resulting sound unacceptable. Much like the battles over vinyl vd CD vs MP3 and tubes vs solid state in the music world, some ears are very sensitive to the aural content while others are quite insensitive. In a search to find a better sound for my 880, I contacted Bob, AB5N, who sells upgrades to a vatiety on ham microphones hoping he could provide a solution. below is his response. I hope it helps explain the problem. 73, Ted W1GRI Ted- We have a conundrum here. Most people buy the ID-880H to use it on D-Star. Otherwise they would just buy a less-expensive rig. D-Star is a extremely compressed digital voice mode. They don't want to digitize any audio that isn't directly responsible for intelligibility. That passband is 300-3000... the old telephone response. Any audio that is outside that range would just be wasting bits encoding sound that does not help you understand what is being said. So, the mic audio is tailored narrowly to that passband for D-Star in the radio. Problem is, on FM, it sounds light at the bottom. If it was me, I would have had separate mic EQ circuits switched in for each mode. Thus, if we change the mic response curve to un-do what the mic pre-amp EQ's are doing, D-Star will go down the drain. Digital distortion is horrible. I've tried this experiment with my ID-800. I had to remove the new element and go stock again. As well, Icom engineers have always felt that their radios should have communications-grade audio. None of their FM radios sound as pleasing as say a Yaesu FM mobile (totally analog radios). When you go to an Icom like a IC-7000, it is like comparing a vinyl record with a MP3. So, for radios that use the 133 or 131 - which do not have D-Star, indeed my mic element gives a very nice improvement. Uh oh... major storm here...tornado warnings.. I better unplug the router and laptop. Hope that clears it up... I wish I could help! Bob-AB5N _ From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of n2gyn Sent: Wednesday, September 01, 2010 14:27 To: dstar_digital@yahoogroups.com Subject: [DSTAR_DIGITAL] Re: Bit Rate? Thank you all for you reply and comments. Let me make myself clearer. I would like to see the audio quality of D-Star be improved. To MY ears' everyone sound like a robot. I thought this was due to the low bit rate. I am NOT impressed with the digital voice mode. I want to hear a more natural sounding voice. My telephone sounds better. How could this be achieved if not by bit rate? John --- In dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com , Ted Wrobel twro...@... wrote: Hi John, Not quite sure what you are thinking, but here is a brief overview of the DStar data stream. The input to / output from the data processing 'module' of the radio is a 9600 Baud stream - which equates to roughly 960 eight bit characters per second. The logic of the system digitizes the voice in and passes it to the AMBE Vocoder that compresses the data stream - a lot. It is the compresion by the Vocoder that is both the strength and weakness of DStar. The compression makes a low data rate (and thus low bandwidth) possible, but it also means that the re-constituted voice is an approximation of the voice input. Generally the reconstructed voice is pretty good, and given the bandwidth it is really quite remarkable. In any case, the baud rate of the system is fixed and cannot be modified at any stage of the process without making the resulting stream unrecognizable to other DStar systems. Note that the data rate over the internet can be much higher, but the chain from repeater controller to / from the radio is fixed for DV comms at 9600. 73 Ted W1GRI _ From: dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com [mailto:dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com ] On Behalf Of n2gyn Sent: Tuesday, August 31, 2010 16:54 To: dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com Subject: [DSTAR_DIGITAL] Bit Rate? Most radios are sent to 8bit. Can all radio's bit rate be changed? I believe it is the LOW
RE: [DSTAR_DIGITAL] Re: Bit Rate?
John, Try plugging a better quality speaker into the radio. I personally find this does wonders to increase fidelity. Icom should be ashamed of the speakers in the D-Star HT's. I'm not sure, but there also may be something else going on as well. If I set up my 80 or 880 and connect to a reflector and do the same with the ID-1 using the same speaker, the fidelity improves big time with the 80 and 880 but the ID-1 still sounds much better (and the RF signal is much weaker). Gary KB2BSL WG2MSK repeater From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of n2gyn Sent: Wednesday, September 01, 2010 2:27 PM To: dstar_digital@yahoogroups.com Subject: [DSTAR_DIGITAL] Re: Bit Rate? Thank you all for you reply and comments. Let me make myself clearer. I would like to see the audio quality of D-Star be improved. To MY ears' everyone sound like a robot. I thought this was due to the low bit rate. I am NOT impressed with the digital voice mode. I want to hear a more natural sounding voice. My telephone sounds better. How could this be achieved if not by bit rate? John --- In dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com , Ted Wrobel twro...@... wrote: Hi John, Not quite sure what you are thinking, but here is a brief overview of the DStar data stream. The input to / output from the data processing 'module' of the radio is a 9600 Baud stream - which equates to roughly 960 eight bit characters per second. The logic of the system digitizes the voice in and passes it to the AMBE Vocoder that compresses the data stream - a lot. It is the compresion by the Vocoder that is both the strength and weakness of DStar. The compression makes a low data rate (and thus low bandwidth) possible, but it also means that the re-constituted voice is an approximation of the voice input. Generally the reconstructed voice is pretty good, and given the bandwidth it is really quite remarkable. In any case, the baud rate of the system is fixed and cannot be modified at any stage of the process without making the resulting stream unrecognizable to other DStar systems. Note that the data rate over the internet can be much higher, but the chain from repeater controller to / from the radio is fixed for DV comms at 9600. 73 Ted W1GRI _ From: dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com [mailto:dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com ] On Behalf Of n2gyn Sent: Tuesday, August 31, 2010 16:54 To: dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com Subject: [DSTAR_DIGITAL] Bit Rate? Most radios are sent to 8bit. Can all radio's bit rate be changed? I believe it is the LOW bit rate that lowers the quality of d-star's audio. Is there a sub menu in the radio's. Also can the repeater's rate be change to a higher rate? John
Re: [DSTAR_DIGITAL] Re: Bit Rate?
If the bit rate is faster, is not the signal wider as well? Would we be sacrificing a narrow band mode to achieve a faster bit rate? Digital TV looks and sounds great but the signal width is awesome! Those who think SSB can be improved and achieve a broadcast-quality signal by adding audio processors are also widening their signals on the band. As someone else has already mentioned, it might take a complete overhaul of the vocoder, rendering everyone's current radio obsolete. However, I agree with you in some respects. I wish the audio coming from the radio were better and not so tinny-sounding. I have improved the audio quality more to my liking by adding an external speaker with good low frequency response. It makes a big difference especially as I have some high frequency hearing loss from my years in the military. 73 de Tim, AF1G n2gyn li...@gmx.net wrote: = Thank you all for you reply and comments. Let me make myself clearer. I would like to see the audio quality of D-Star be improved. To MY ears' everyone sound like a robot. I thought this was due to the low bit rate. I am NOT impressed with the digital voice mode. I want to hear a more natural sounding voice. My telephone sounds better. How could this be achieved if not by bit rate? John --- In dstar_digital@yahoogroups.com, Ted Wrobel twro...@... wrote: Hi John, Not quite sure what you are thinking, but here is a brief overview of the DStar data stream. The input to / output from the data processing 'module' of the radio is a 9600 Baud stream - which equates to roughly 960 eight bit characters per second. The logic of the system digitizes the voice in and passes it to the AMBE Vocoder that compresses the data stream - a lot. It is the compresion by the Vocoder that is both the strength and weakness of DStar. The compression makes a low data rate (and thus low bandwidth) possible, but it also means that the re-constituted voice is an approximation of the voice input. Generally the reconstructed voice is pretty good, and given the bandwidth it is really quite remarkable. In any case, the baud rate of the system is fixed and cannot be modified at any stage of the process without making the resulting stream unrecognizable to other DStar systems. Note that the data rate over the internet can be much higher, but the chain from repeater controller to / from the radio is fixed for DV comms at 9600. 73 Ted W1GRI _ From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of n2gyn Sent: Tuesday, August 31, 2010 16:54 To: dstar_digital@yahoogroups.com Subject: [DSTAR_DIGITAL] Bit Rate? Most radios are sent to 8bit. Can all radio's bit rate be changed? I believe it is the LOW bit rate that lowers the quality of d-star's audio. Is there a sub menu in the radio's. Also can the repeater's rate be change to a higher rate? John
Re: [DSTAR_DIGITAL] Re: Bit Rate?
John, D-STAR has a very specific standard for the on air digital voice signal. The signal rate must be 4800 bps (to achieve 6.25khz. bandwidth). Any variance from that rate and you have broken the standard and would be incompatible with D-STAR. The specification also requires the use of AMBE vocoder technology. The specification also requires the use of the 3600 bps encoding (2400 bps voice + 1200 bps forward error correction or FEC) and any other values would be incompatible even though the AMBE vocoder can be run at other rates and voice to FEC ratios. After you use 3600 bps for voice+FEC, there is an additional 1200 bps that is used for protocol addressing and various user defined data components (Icom has added some useful extensions in that space, GPS, Short Text, some protocol redundancy). To move outside of these standards is certainly within the realm of amateur radio and amateur radio experimentation but D-STAR is very defined, by the JARL, as to what can be done. If one wants a higher fidelity voice signal, then one is free and encouraged to experiment, but it won't be D-STAR and won't be able to take advantage of the D- STAR infrastructure. Certainly the manufacturer of AMBE technology works to improve the encoding and decoding of voice and could possibly come up with new generations of chips to fit the D-STAR parameters, but they would have to be backward compatible for acceptance in the market. The final sound of the AMBE signal after decoding is not an exact, high fidelity, reproduction of the original voice encoding, but for the sake of communicating intelligence it works very well (assuming the speaker is speaking intelligently :) ). Different people have different perspectives on that audio, for example, one local ham finds the AMBE processed voice easier to listen to due to his specific hearing ability. There are some in the hobby that would go for FM broadcast quality fidelity, but it is terribly inefficient from a spectrum point of view. Higher encoding bit rates could provide higher fidelity, for example Sirius digital satellite radio uses AMBE as well, but again it would be at the sacrifice of bandwidth for what is a communications service that does not need the fidelity and musicality of an entertainment service. AMBE is a registered trademark of Digital Voice Systems, Inc. D-STAR is a trademark of the JARL (in Japan) and a registered trademark of Icom in the US and several other markets. On Sep 1, 2010, at 11:26 AM, n2gyn wrote: Thank you all for you reply and comments. Let me make myself clearer. I would like to see the audio quality of D-Star be improved. To MY ears' everyone sound like a robot. I thought this was due to the low bit rate. I am NOT impressed with the digital voice mode. I want to hear a more natural sounding voice. My telephone sounds better. How could this be achieved if not by bit rate? John John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
RE: [DSTAR_DIGITAL] Re: Bit Rate?
At 05:05 AM 9/2/2010, you wrote: John, Try plugging a better quality speaker into the radio. I personally find this does wonders to increase fidelity. Icom should be ashamed of the speakers in the D-Star HT's. A better quality speaker certainly works, as anyone who's listened to a DV Dongle on PC speakers can attest to. Actually, I find the quality of the audio of my 91AD is very good (for a HT), only complaint is there's not enough of it for some environments. As for the robotic sound, well, we're stuck with it. The whole point of speech codecs is to literally throw away anything that's not directly contributing to intelligibility, to reduce the bitrate. There is a tradeoff here between bitrate and fidelity. AMBE is designed to achieve very low bitrates, so it's not going to sound very natural. My own view of D-STAR audio is that while it doesn't sound natural, I find it very intelligible, often more so than FM in the real world (where there's a lot of poorly adjusted radios and radios with wonky audio response). I'm also able to recognise who is speaking, so enough of the voice is preserved to allow that. The AMBE vocoder excels at what it sets out to do in my opinion - provide communications grade speech at very low bitrates. I'm not sure, but there also may be something else going on as well. If I set up my 80 or 880 and connect to a reflector and do the same with the ID-1 using the same speaker, the fidelity improves big time with the 80 and 880 but the ID-1 still sounds much better (and the RF signal is much weaker). Different radios will have different audio responses. RF signal strength is largely irrelevant in D-STAR, until the bit error rate starts to increase significantly to the point that the FEC has trouble correcting those errors. 73 de VK3JED / VK3IRL http://vkradio.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
IMHO the robotic sound is not going away with D-Star. Of course the D-Star radios have standard FM which you can use. If you decide to sell the 91AD rest assured that it will be bought by someone quickly. On 9/1/2010 18 43 Hours, n2gyn wrote: I guess I just can not live with the robotic sound. This is unacceptable in this world of technology. I am trying to find away around this before I dump the whole D-Star thing. John PS: I also have a 91AD --- In dstar_digital@yahoogroups.com mailto:dstar_digital%40yahoogroups.com, Tony Langdon vk3...@... wrote: At 05:05 AM 9/2/2010, you wrote: John, Try plugging a better quality speaker into the radio. I personally find this does wonders to increase fidelity. Icom should be ashamed of the speakers in the D-Star HT's. A better quality speaker certainly works, as anyone who's listened to a DV Dongle on PC speakers can attest to. Actually, I find the quality of the audio of my 91AD is very good (for a HT), only complaint is there's not enough of it for some environments. As for the robotic sound, well, we're stuck with it. The whole point of speech codecs is to literally throw away anything that's not directly contributing to intelligibility, to reduce the bitrate. There is a tradeoff here between bitrate and fidelity. AMBE is designed to achieve very low bitrates, so it's not going to sound very natural. My own view of D-STAR audio is that while it doesn't sound natural, I find it very intelligible, often more so than FM in the real world (where there's a lot of poorly adjusted radios and radios with wonky audio response). I'm also able to recognise who is speaking, so enough of the voice is preserved to allow that. The AMBE vocoder excels at what it sets out to do in my opinion - provide communications grade speech at very low bitrates. I'm not sure, but there also may be something else going on as well. If I set up my 80 or 880 and connect to a reflector and do the same with the ID-1 using the same speaker, the fidelity improves big time with the 80 and 880 but the ID-1 still sounds much better (and the RF signal is much weaker). Different radios will have different audio responses. RF signal strength is largely irrelevant in D-STAR, until the bit error rate starts to increase significantly to the point that the FEC has trouble correcting those errors. 73 de VK3JED / VK3IRL http://vkradio.com attachment: jozef.vcf
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On Sep 1, 2010, at 3:19 PM, n2gyn wrote: It's NOT a microphone issue. It's the small bit processing. I have been in Pro sound for most of my life. Their is NO WAY to get any quality at 8bit. This is unexceptionable to me! I rather listen to all the QRM and QRN in the world with analog. I am very surprise that their are not more people that feel this way. The bit rate has to be at lest 28bit to starting sounding acceptable. John It isn't a microphone issue (nor is it an 8 bit A/D issue) -- AMBE is not a simple A/D waveform sampler, it examines the complex signal and encodes hints via a codebook to reproduce the waveform, that is how it gets its amazing compression. This is not an apples to apples comparison. The sample rate and number of bits per sample are important to providing a good input signal but the chip really is looking for 8 Khz (16-bit linear, ųlaw, or alaw -- optionally 32Khz using AD 73311 -- see http://www.dvsinc.com/manuals/ AMBE-2020_manual.pdf Page 39) and puts out the same, but in between it doesn't resemble anything close to a bit sampler. Anything one knows about sample rates and size (in bits) is largely irrelevant as the limiting factor is the AMBE algorithm and its lookup codebook. http://en.wikipedia.org/wiki/Advanced_Multi-Band_Excitation John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
Re: [DSTAR_DIGITAL] Re: Bit Rate?
John: Actually, it's neither. 8 bits is actually sufficient to reproduce fairly low distortion audio, given a good sample rate, but with limited dynamic range. Since communication quality audio doesn't require much dynamic range, that's not a problem. I don't believe the fact that it's an 8 bit quantization is much of a factor in the quality of the resulting communications and I don't think there's much reason to go beyond 8 bits. Being in pro sound is clearly biasing your perspective on this. I certainly wouldn't want an 8 bit music system, but for communications, I think it's fine. For voice communications, 28 bits would be beyond overkill. The real issue is the data compression technology, which compromises sound quality to limit data bandwidth. Still, I've heard some pretty acceptable D-Star audio from good stations with good signals. It's not live, but that's not the point. If you feel a need for high quality audio Hamming, I suggest you visit with the guys that hang out around 14.180 KHz. (Is that the frequency?). Chuck - N8DNX On 9/1/2010 6:19 PM, n2gyn wrote: It's NOT a microphone issue. It's the small bit processing. I have been in Pro sound for most of my life. Their is NO WAY to get any quality at 8bit. This is unexceptionable to me! I rather listen to all the QRM and QRN in the world with analog. I am very surprise that their are not more people that feel this way. The bit rate has to be at lest 28bit to starting sounding acceptable. John
Re: [DSTAR_DIGITAL] Re: Bit Rate?
At 08:43 AM 9/2/2010, you wrote: I guess I just can not live with the robotic sound. This is unacceptable in this world of technology. I am trying to find away around this before I dump the whole D-Star thing. As stated, fidelity is not the point of D-STAR. It's voice/data communications using the minimum feasible bandwidth. 73 de VK3JED / VK3IRL http://vkradio.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
On Sep 1, 2010, at 4:53 PM, Tony Langdon wrote: As stated, fidelity is not the point of D-STAR. It's voice/data communications using the minimum feasible bandwidth. 73 de VK3JED / VK3IRL http://vkradio.com And for the HF DV experimenter it looks like DVSI now has a chip to do 1200 or 1800 bps (no FEC) AMBE. John D. Hays Amateur Radio Station K7VE PO Box 1223 Edmonds, WA 98020-1223 VOIP/SIP: j...@hays.org
RE: [DSTAR_DIGITAL] Re: Bit Rate?
AMEN! It's COMMUNICATIONS QUALITY audio. not high fidelity! 73, Mike WM4B From: dstar_digital@yahoogroups.com [mailto:dstar_digi...@yahoogroups.com] On Behalf Of Tony Langdon Sent: Wednesday, September 01, 2010 7:54 PM To: dstar_digital@yahoogroups.com Subject: Re: [DSTAR_DIGITAL] Re: Bit Rate? As stated, fidelity is not the point of D-STAR. It's voice/data communications using the minimum feasible bandwidth. 73 de VK3JED / VK3IRL http://vkradio.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
At 10:16 AM 9/2/2010, you wrote: And for the HF DV experimenter it looks like DVSI now has a chip to do 1200 or 1800 bps (no FEC) AMBE. Hmm, maybe room for a HF dongle for experimenters. :) Of course, a pure software vocoder has its advantages, but there's room to try different approaches. 73 de VK3JED / VK3IRL http://vkradio.com
Re: [DSTAR_DIGITAL] Re: Bit Rate?
There is a lot of room in our hobby for many niche interests and points of view. I became a Ham in the late 1950s and while I started out on AM, I switched to SSB fairly soon after. I have always liked communications quality audio for voice communications. When I discovered a whole subculture of Hams interested in Extended SSB, I had trouble understanding why. I listen to some people with carefully adjusted equalizers that sound like they are transmitting from their bathroom, what with echos etc. But then I realized that as long as they don't hog the bandwidth when a band is busy, there is nothing wrong with them wanting something more than communications quality. I just expect them to respect my preference for narrower audio response over RF. I am thinking D-Star will probably not work out for John, and he'll decide to move on to other parts of Ham radio. Or he'll get involved in experimentation with other types of digital radio that may involve other vocoders and different design parameters (I wonder what Codec2 sounds like?). And if we all live long enough, we will probably see other DV standards evolve. I like to think that if we left the planet and came back in 50 years, the vast majority of Ham transmissions will be some form of digital. It's inevitable. For John's sake, let's hope he has some audio quality choices. In the meantime, I like D-Star audio just fine, since I'm able to understand what everyone is saying. Jim - K6JM - Original Message - From: n2gyn To: dstar_digital@yahoogroups.com Sent: Wednesday, September 01, 2010 3:19 PM Subject: [DSTAR_DIGITAL] Re: Bit Rate? It's NOT a microphone issue. It's the small bit processing. I have been in Pro sound for most of my life. Their is NO WAY to get any quality at 8bit. This is unexceptionable to me! I rather listen to all the QRM and QRN in the world with analog. I am very surprise that their are not more people that feel this way. The bit rate has to be at lest 28bit to starting sounding acceptable. John
