Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
Oops, I forgot about that 400 ms time segment! Yes, now I see what you mean. Thanks for helping clarify this. 73, Rick, KV9U cesco12342000 wrote: >>From my understanding of the documentation for WinDRM, MELP >>does work if the speed is at least 1,000 bps. >> >> > >No. 1000 bp400ms (bit per 400 ms) or 2400 bps >This per second / per 400 millisecond mixture is confusing ! > > > > > > >Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org > >Other areas of interest: > >The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ >DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) > > >Yahoo! Groups Links > > > > > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Digital Voice: Some thoughts after one week.
> From my understanding of the documentation for WinDRM, MELP > does work if the speed is at least 1,000 bps. No. 1000 bp400ms (bit per 400 ms) or 2400 bps This per second / per 400 millisecond mixture is confusing ! Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Digital Voice: Some thoughts after one week.
--- In digitalradio@yahoogroups.com, "Patrick Lindecker" <[EMAIL PROTECTED]> wrote: > I have listened some test in spanish with artificial voice reading words. It was not too bad. The real problem is to translate voice in symbols, in a reliable way. > Yes. There was that fairly recent QST article about using voice recognition software to operate PSK or other keyboard modes by voice. I copied a guy using it - it did fairly well, but of course had trouble with homonyms: e.g. "to" and "two" and "too" Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
Glad that I was understanding that the 4-QAM was for the text part and not voice. At least at this point of technology advancement. Also, you had said earlier that: "Tests with a 1200 bit/sec LPC codec have been negative (bad intellegibility)." From my understanding of the documentation for WinDRM, MELP (which is really a form of LPC) does work if the speed is at least 1,000 bps. So what LPC codec is it that does not work at 1,200 bps? 73, Rick, KV9U cesco12342000 wrote: > See the list on the windrm spec page. > >http://www.qslnet.de/member/hb9tlk/drm_h.html > > > >>If LPC doesn't work at 1200 bps, >> >>And apparently it works OK at 1000 bps? >> >> > >I dont understand. > > > > > > >Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org > >Other areas of interest: > >The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ >DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) > > >Yahoo! Groups Links > > > > > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
Hi Patrick and group, I wonder if there would be much interest in this kind of DV? The main argument was for having a high quality sounding voice in real time. In the early 1980's, there used to be a product called HERO (Heath Educational Robot) which allowed simple phoneme entry so that it could "speak." Of course it did a lot more with a robot arm and was ambulatory and had various sensors and sonar ranging, etc. I built one of these kits for a shared robot experience with our school districts and used to demonstrate it to teachers. The programming could be entered manually via a keypad. The voice quality not always easy to understand, and it was definitely what we call robotic:) If the phoneme quality was improved with a clearer sound that I am sure can be done with today's technology, I can see where a phoneme based system could theoretically work. I am not sure if it would receive wide adoption, but if it was the only way to effect weak signal voice, maybe it could have a niche area of interest? I wonder what other group members think about that? 73, Rick, KV9U Patrick Lindecker wrote: >Hello Rick, > > > >The only solution to do voice exchange with a low S/N would be to translate >all the pronounced words in symbols (through some program able to "understand" >voice, the symbols being phonemes or words), to code these symbols through a >Varicode with, for example 40.000 different symbols, to transmit these symbols >and to reverse the process at reception: decoding of the symbols and >pronunciation through an auxiliary program handling an artificial voice. >The transmission mode would be some MFSK16 or Contestia mode (rapid and >reliable). > >I have listened some test in spanish with artificial voice reading words. It >was not too bad. The real problem is to translate voice in symbols, in a >reliable way. > >I think that, in this way, the compression of the information would be close >to the maximum. > >73 >Patrick > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: DV
AOR Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: The Rules are a changing!!! FCC publishes it changes
--- In digitalradio@yahoogroups.com, Rick Ellison <[EMAIL PROTECTED]> wrote: > > > > http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-06-149A1.doc > > > 73's Rick N2AMG > Aim:n2amg > Yahoo:n2amg > By the way, whatever happened to the plan to ditch CW as a license requirement for HF? Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: DV
--- In digitalradio@yahoogroups.com, John Becker <[EMAIL PROTECTED]> wrote: > > Sitting on 7240 for a while. > Which DV? Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] DV
Sitting on 7240 for a while. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Digital Voice: Some thoughts after one week.
> The only solution to do voice exchange with a low S/N would > be to translate all the pronounced words in symbols Exactly what i am thinking! We need to establish a "phoneme alphabet". Then, a correlator is needed to extract those phonems from the voice input. Each phonem should have duration and pitch indicators to allow a more individual reconstruction of the voice. This would result in a robust, low-bitrate and somewhat robotic DV system. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Digital Voice: Some thoughts after one week.
> It was my understanding that the QAM-4 modulation was used for the > text transmission Negative. Text and data can be anything from qam-4 to qam-64 FAC data (the callsign) is the only thing which is always qam-4 > and you needed to use at least QAM-16 for the > voice. Since the codecs used have 2400bps data rate, qam-16 is necessary. But if you find a decent 1200bps codec, data rate is lower, and qam-4 could be enough. > How many bps can you get through with QAM-4? See the list on the windrm spec page. http://www.qslnet.de/member/hb9tlk/drm_h.html > If LPC doesn't work at 1200 bps, > > And apparently it works OK at 1000 bps? I dont understand. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
Hello Rick, >Does anyone have any "inside" information that would suggest that we >will be able to lower the required S/N ratios for a given speed or are >we already too close to the Shannon Limit as it is? The only solution to do voice exchange with a low S/N would be to translate all the pronounced words in symbols (through some program able to "understand" voice, the symbols being phonemes or words), to code these symbols through a Varicode with, for example 40.000 different symbols, to transmit these symbols and to reverse the process at reception: decoding of the symbols and pronunciation through an auxiliary program handling an artificial voice. The transmission mode would be some MFSK16 or Contestia mode (rapid and reliable). I have listened some test in spanish with artificial voice reading words. It was not too bad. The real problem is to translate voice in symbols, in a reliable way. I think that, in this way, the compression of the information would be close to the maximum. 73 Patrick - Original Message - From: KV9U To: digitalradio@yahoogroups.com Sent: Wednesday, October 11, 2006 10:54 PM Subject: Re: [digitalradio] Re: Digital Voice: Some thoughts after one week. The one common theme I see with much of the digital modes that require the higher level of speed is that the required minimum S/N ratio hovers around 10 db S/N. It seems to be true with DV voice, with SCAMP, and also with high baud rate modes (such as trying to exceed a few hundred baud on HF).To me there is a dividing line between real time voice and high speed digital texting vs. slower modes that get through under difficult conditions. Actually, difficult conditions tend to be more of the norm on HF.Does anyone have any "inside" information that would suggest that we will be able to lower the required S/N ratios for a given speed or are we already too close to the Shannon Limit as it is?If we can not do this, I don't see how any of the higher speed digital modes will ever be able to replace analog communications for weak signal and general amateur radio communications with modest power levels and modest antennas. In other words, what most of us do most of the time.Of course this would not be true for VHF and up, only for the restricted BW's of HF.73,Rick, KV9UDuBose Walt Civ AETC CONS/LGCA wrote:>Ed,>>Back in the fall of 1989, we started using a unit called the TacTerm for DV. The best modem was a 39 parallel tone modem (Mil-Std-188-110?) and 2400 BPS. On HF it sounded funny...robotic like...and while it did work on about the same SNR as a ~S3 SSB signal ...the SNR had to be about 10 dB, it worked much better on VHF and UHF FM as well as UHF AM.>>In Jan-Feb 1990, after Operation Just Cause, I got to play with a Harris Mil-Std-188-110? modem and DV at 2400 BPS AND 4800 BPS. The 2400 bps DV still sounded a bit robotic but worked quite well at S2-S3 signals and even when the SNR was at or I think slightly below 10 dB. The modem had ALE and provided a SNR figure and my old ham radio ear figured an S2-3 signal.>>When we switched to 4800 bps, the DV sounded just like the individual speaking over a telephone...better than SSB voice but it required a slightly better SNR.>>Data with the TacTerm 39 tone modem was really good...text came through at about a page a minute with a signal that you could hear. When the signal got down close to the noise...where you had to strain to hear it, the throughput went down to maybe 20-30 lines per minutebut still near 100% copy (could have been typing errors). The actual computer software was KA9Q NOS running on a BIG military laptop computer.>>When we went to the Harris modem and 2400 BPS/4800 BPS, the copy at 2400 BPS was about the same with a good signal but better than the TacTerm with lower qualitity signals.>>4800 bps screemed unless the signal got below 10 dB SNR or so.>>During Operations Desert Shield and Desert Storm, the U.S. Marine Corp used a Hughes RT-1209 and Harris AM-6545A 400 watt amplifier to make up the GRC-193A (http://www.nj7p.org/millist/pic/grc-193.gif) used in some of the last productions Jeeps and Humvees. Most were using a 15-16 ft fold over whip. The whip went up just about 18" higher then the Humvee top and then tilted over and ran horizontal the remainder of the length. This provided a good NVIS antenna radiation pattern.>>The Marine Corp did connect the Harris MIL-STD-188-110x modem to the GRC-193 and used a computer to send data from the field back to their command center.>>For digital voice I believe that some units used the Navy's version of the TacTerm and some may have been using the later ITT MinTerm DV unit. The TacTerm (KY-57) can accept signal fades of up to 12 seconds without losing synchronization with the transmitting station.>>I never noticed
[digitalradio] Revised FCC rules for data/image communication
New FCC rulesdigital related, see below. Oct 10, 2006 . 15. Image Emissions. Background. Amateur radio operators have recently been using personal computers with sound cards and software to develop new communication systems and technologies that are capable of transmitting both image and data emission types. One system in use, for instance, combines a digital emission and a narrowband facsimile (FAX) emission. Another system, sometimes referred to as the "Hellschriber" system, uses transmitted pulses to directly write images on paper or a computer screen. Amateur radio operators worldwide have been using these new communications systems without causing harmful interference to other amateur service communications. Such use appears to be consistent with one of the purposes of amateur service, namely, to contribute to the advancement of the radio art. Nevertheless, our Part 97 rules do not now authorize amateur stations to transmit both image and data emission types on any HF frequency segments, though they do authorize image emission types to be transmitted on frequency segments also authorized for phone communications. 16. In the NPRM, the Commission sought comment on whether it should revise the definition of data emission types contained in Section 97.3(c) of our Rules to include emission types A1C and F2C. This would permit amateur stations to transmit FAX emissions having an occupied bandwidth of 500 Hz or less on the frequency segments used for data communications. The NPRM also noted that limiting the occupied bandwidth of image emissions in data segments of the HF bands to 500 Hz or less would provide the amateur service community greater flexibility in developing communication systems and communications technology, thereby furthering that purpose of the amateur service while maintaining the narrow bandwidth nature of the data emission band segments. 17. Decision. All commenters who addressed this issue support the NPRM proposal to revise the definition of data in the amateur service rules. We agree that permitting images to be transmitted on data emission frequency segments will "allow amateur radio to make the most of new [software] programs" thereby "advanc[ing] its technology." 18. We agree with the majority of commenters that analog emissions should not categorically be excluded from the definition of data emission types because the frequency segments authorized for data emissions also are authorized for certain analog emission types. Although ARRL agrees with the concept of permitting images to be transmitted in HF segments where data emissions are currently allowed, it requests that we exclude analog image emissions from the definition of data, because it asserts that analog emissions "would be inhomogeneous with the digital emissions in the segments in which CW, RTTY, and data emissions are permitted." However, many other commenters request that we include emission designators J2C and J3C in the definition of data so that data communications transmitted by amateur stations may include narrow bandwidth analog images. We also note that no commenter has claimed that interference occurs between these different types of emissions and that many commenters support allowing narrow bandwidth analog image emissions in digital frequency segments. Based on the record before us, we believe that we should allow amateur stations to transmit narrow bandwidth analog image emissions in digital frequency segments. Accordingly, we revise the definition of data to include emission designators J2C and J3C. We also include emission type F1C, because F1C is the emission type that amateur stations transmit when they are using multiple frequency shift keying (MFSK). 19. ARRL also requests that we not impose a 500 Hz bandwidth limitation in the definition of data emissions, arguing that this limitation would have unintended consequences because the limitation also applies to amateur service bands in which a higher symbol rate or bandwidth is permitted. We understand ARRL's concern, but we note that eliminating or relaxing the bandwidth limitation would de facto eliminate the separation of narrow bandwidth and wide bandwidth emissions. We believe that separation of emission types by bandwidth is accepted in the amateur service as a reasonable means to minimize interference on shared frequencies and bands and, therefore, we will not replace the 500 Hz bandwidth limitation with a 3 kHz bandwidth limitation. To accommodate the concern raised by ARRL, however, we will revise our rules to clarify that the 500 Hz limitation applies only to the emission types we are adding to the definition of data when transmitted on amateur service frequencies below 30 MHz. By amending the rule in this manner, the 500 bandwidth limitation will not apply to other data emission types or amateur service bands in which a higher symbol rate or bandwidth currently is permitt
Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
The one common theme I see with much of the digital modes that require the higher level of speed is that the required minimum S/N ratio hovers around 10 db S/N. It seems to be true with DV voice, with SCAMP, and also with high baud rate modes (such as trying to exceed a few hundred baud on HF). To me there is a dividing line between real time voice and high speed digital texting vs. slower modes that get through under difficult conditions. Actually, difficult conditions tend to be more of the norm on HF. Does anyone have any "inside" information that would suggest that we will be able to lower the required S/N ratios for a given speed or are we already too close to the Shannon Limit as it is? If we can not do this, I don't see how any of the higher speed digital modes will ever be able to replace analog communications for weak signal and general amateur radio communications with modest power levels and modest antennas. In other words, what most of us do most of the time. Of course this would not be true for VHF and up, only for the restricted BW's of HF. 73, Rick, KV9U DuBose Walt Civ AETC CONS/LGCA wrote: >Ed, > >Back in the fall of 1989, we started using a unit called the TacTerm for DV. >The best modem was a 39 parallel tone modem (Mil-Std-188-110?) and 2400 BPS. >On HF it sounded funny...robotic like...and while it did work on about the >same SNR as a ~S3 SSB signal ...the SNR had to be about 10 dB, it worked much >better on VHF and UHF FM as well as UHF AM. > >In Jan-Feb 1990, after Operation Just Cause, I got to play with a Harris >Mil-Std-188-110? modem and DV at 2400 BPS AND 4800 BPS. The 2400 bps DV still >sounded a bit robotic but worked quite well at S2-S3 signals and even when the >SNR was at or I think slightly below 10 dB. The modem had ALE and provided a >SNR figure and my old ham radio ear figured an S2-3 signal. > >When we switched to 4800 bps, the DV sounded just like the individual speaking >over a telephone...better than SSB voice but it required a slightly better SNR. > >Data with the TacTerm 39 tone modem was really good...text came through at >about a page a minute with a signal that you could hear. When the signal got >down close to the noise...where you had to strain to hear it, the throughput >went down to maybe 20-30 lines per minutebut still near 100% copy (could >have been typing errors). The actual computer software was KA9Q NOS running >on a BIG military laptop computer. > >When we went to the Harris modem and 2400 BPS/4800 BPS, the copy at 2400 BPS >was about the same with a good signal but better than the TacTerm with lower >qualitity signals. > >4800 bps screemed unless the signal got below 10 dB SNR or so. > >During Operations Desert Shield and Desert Storm, the U.S. Marine Corp used a >Hughes RT-1209 and Harris AM-6545A 400 watt amplifier to make up the GRC-193A >(http://www.nj7p.org/millist/pic/grc-193.gif) used in some of the last >productions Jeeps and Humvees. Most were using a 15-16 ft fold over whip. >The whip went up just about 18" higher then the Humvee top and then tilted >over and ran horizontal the remainder of the length. This provided a good >NVIS antenna radiation pattern. > >The Marine Corp did connect the Harris MIL-STD-188-110x modem to the GRC-193 >and used a computer to send data from the field back to their command center. > >For digital voice I believe that some units used the Navy's version of the >TacTerm and some may have been using the later ITT MinTerm DV unit. The >TacTerm (KY-57) can accept signal fades of up to 12 seconds without losing >synchronization with the transmitting station. > >I never noticed any delays or words that were not understandable using the >TacTerm or MinTerm or Harris Modem using LCP-10 and UG-??? encryption unit. >There were of course a second or two between transmissions, but certainly not >enough to prevent artillary spotting or fire control. > >The PRC-109/GRC-193 systems were used at least in 1985 and perhaps before with >the TacTerm. The TacTerm was used in the Viet Nam war on HF SSB, VHF and UHF >AM and as far as I know without problems. The C-130s tracking and Navy vessel >captured by North Korea used Tacterm's on HF and the crew of the C-130 never >mentioned to me that there were communications using the TecTerm. > >So when the Marine Corp have problems with DV must have been shortly after the >capture of the USS Pubelo which I believe was in 1968. > >A good reference on the ANDVT modem may be _HF modem evaluations for the >Advanced Narrowband Digital Voice Terminal (ANDVT)_ by Chase, D.; Bello, P. >A.; Boardman, C.; Pickering, L.; Pinto, R. published in Nov 1978 > >Abstract: >"During this program, the specifications for the ANDVT HF modem have been >refined and detailed evaluation and simulation of the new technical features >within this modem have been conducted. These include a multiple-tone signal >detection format with an adaptive
[digitalradio] Re: Digital Voice: Some thoughts after one week.
--- In digitalradio@yahoogroups.com, "DuBose Walt Civ AETC CONS/LGCA" <[EMAIL PROTECTED]> wrote: > > I've heard DV using LCP-10 and a 16 tone modem as well as a 39 tone modem at 1200 bps...it sounds robotic at best. But that could have been just the systems used (ANDVT/Mil-STD-188-110) > > Walt/K5YFW Walt, Thanks for your very interesting and informative comments. I would be very interested in meeting you on the air for an extended conversation on the subject. We should be able to connect on 40M or 80M in the evenings. I often monitor 7295 +/-. I can also be reached on EchoLink. Some of the questions I have are: 1) Can you suggest a reference on HF propagation that may show distributions or histograms of fade depths, durations and bandwidths? 2) For the examples of military equipment you gave, did they use voice bandwidths (~2.5 KHz) or were the bandwidths larger? 3) With military communications I expect that voice quality and accuracy of the communication is essential. For ham weak signal applications where accuracy is not a life and death matter, can we gain any performance by trading codec data for FEC data? If voice quality at 2400 bps is considered acceptable for military applications, can we get better SNR performance with useable voice quality for ham applications at codec data rates less than 2400 bps with stronger FEC? Is there anyone reading this thread that could develop additional experimental modes for WinDRM? Ed WB6YTE Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] The Rules are a changing!!! FCC publishes it changes
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-06-149A1.doc 73's Rick N2AMG Aim:n2amg Yahoo:n2amg Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: First DRM Reception
--- In digitalradio@yahoogroups.com, "jhaynesatalumni" <[EMAIL PROTECTED]> wrote: > > --- In digitalradio@yahoogroups.com, Tony wrote: > > > > Jim > > > > > > You need to mute the MIC audio on your sound card. That will stop > the WinDRM > > digital signal from making it to your PC speakers and mixing with the > > decoded voice. Once it starts to decode, WinDRM will playback the > audio into > > your sound card speakers. > > [snip...] > Well, thanks, but... The soundcard mixer stuff doesn't seem to work > under WINE. I guess I have to use the native Linux mixer. And my > soundcard has only one output, not separate line and speaker outputs. > That's why I think I need another sound card. I use a USB sound card adapter ($10) and a set of headphones with a boom mic ($4) with XP to simplify the setup. The USB sound card driver installation was done automatically by XP. I don't know how difficult it would be with Linux. Ed Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
Al Chandler, K6RFK used to be prominently displayed in some of AEA's advertisements at the peak of their success. He was one of the engineers who I believe was instrumental in the development of the PK-232 and perhaps some of the other interfaces in the CP series. I have had the CP-1 for many years, as well as some of the Kantronics products (remember the UTU?). Also, some HB stuff to get on VHF and HF RTTY until packet came along. Later on the DSP-2232 types of modems. I almost bought one of these but thankfully I did not as I felt uncomfortable with AEA and their plans for supporting this product. I believe that the principal programmer for this product, which was very advanced for its time, was Bob, N4HY. If this product could have supported some of the other modes, it would have been one of the only U.S. products under $1000. But HAL kept Clover proprietary and SCS kept Pactor 2 and 3 proprietary and would not license them to anyone else. So I could see that these were going to be strictly niche products that would never become popular with mainstream digital operation and I left digital modes for a number of years until the miracle of sound card modes became possible. That was one of the largest paradigm shifts in amateur radio in the 40+ years since I was first licensed next to the packet rise and fall. 73, Rick, KV9U DuBose Walt Civ AETC CONS/LGCA wrote: >I don't think that you have to lock yourself into fixed codec's, etc. AEA >made a programmable TNC and I think that you could move this way with an >external box...just adding additional DSP computing power and RAM on the >external device and store the programming and interface (GUI, etc.) on the >main computer. > >I believe that several individuals have experimented with using external DSP >cards rather then the ACP on-board DSP/audio chips or even PCI audio/DSP >boards and found the external audio/DSP boards superior. Perhaps you could >make a PCI extension cable and use multiple audio/DSP boards and custom cable >interfaces...that would be GREAT. For example, perhaps running 2 or 3 >Turtle-Santa Cruz Audio/DSP cards externally? > >I don't like the sound cards puny connections...at least give me RCA jacks. > >Walt/K5YFW > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] On SDR and DRM
The current (October 2006) issue of IEEE Spectrum has an article on another software defined radio, made by Ettus. http://www.ettus.com which is a receive-only item. Also an item about DRM in Europe, which may not catch on because there are few receivers you can buy, and they are expensive, and why should you when you are happy with BC radio as it is? For some reason the U.S. has chosen the proprietary Ibiquity system instead of DRM. The local NPR station announces that they are broadcasting in High Definition Radio, but there don't seem to be any receivers you can buy for it, except perhaps automobile receivers. And then there is a wry note that there is only one ham-type electronics store left in New York City (Barry); the others are all consumer-entertainment types. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] OE3GBB 14236.0 DV 1830z
Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
Ok John...I'll take that on. Oh Ok, maybe but I have run a laptop under the front passenger's seat with a small remote LCD monitor and mouse. But your point IS well taken. Hi Hi. Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 11, 2006 10:12 AM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!! I can't help you either. A bit hard to mount a computer vs AOR DV modem in a mobile set up like I have done. John, W0JAB At 08:41 AM 10/11/2006, you wrote: Paul, Have you found a significant difference between the quality and robustness of the AOR product vs. WinDRM? Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
I don't think that you have to lock yourself into fixed codec's, etc. AEA made a programmable TNC and I think that you could move this way with an external box...just adding additional DSP computing power and RAM on the external device and store the programming and interface (GUI, etc.) on the main computer. I believe that several individuals have experimented with using external DSP cards rather then the ACP on-board DSP/audio chips or even PCI audio/DSP boards and found the external audio/DSP boards superior. Perhaps you could make a PCI extension cable and use multiple audio/DSP boards and custom cable interfaces...that would be GREAT. For example, perhaps running 2 or 3 Turtle-Santa Cruz Audio/DSP cards externally? I don't like the sound cards puny connections...at least give me RCA jacks. Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 11, 2006 8:41 AM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!! Paul, Have you found a significant difference between the quality and robustness of the AOR product vs. WinDRM? It seems to me that external hardware would become obsolete if worked about as well as the free sound card product. This is not unlike the situation that has occured with hardware modems for Pactor, Amtor, etc. While a few (very few) might use them for casual contacts, it is actually very rare now. At one time you would have no trouble finding others to link with. With the hardware solutions though, you lock yourself into a fixed codec that is very likely to change due to constant technology improvements. DiD AOR make some provisions for updates. 73, Rick, KV9U Paul Metzger wrote: >I've been calling CQ for the past couple hours on 40m. But then again, >I'm using the AOR DV units, not WinDRM. > >Sorry. > >Paul Metzger > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [digitalradio] Re: Digital Voice: Some thoughts after one week.
I've heard DV using LCP-10 and a 16 tone modem as well as a 39 tone modem at 1200 bps...it sounds robotic at best. But that could have been just the systems used (ANDVT/Mil-STD-188-110) Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 11, 2006 8:20 AM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: Digital Voice: Some thoughts after one week. It was my understanding that the QAM-4 modulation was used for the text transmission and you needed to use at least QAM-16 for the voice. How many bps can you get through with QAM-4? If LPC doesn't work at 1200 bps, then what other codec do you suggest? Even MELP (which is a type of LPC) normally was based upon a 2400 bps speed was it not? And apparently it works OK at 1000 bps? 73, Rick, KV9U cesco12342000 wrote: > >A codec withh 1000bit/sec would allow qam-4 modulation, and improve >the robustness to "useful" levels. Tests with a 1200 bit/sec LPC >codec have been negative (bad intellegibility). > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [digitalradio] Re: Digital Voice: Some thoughts after one week.
Ed, Back in the fall of 1989, we started using a unit called the TacTerm for DV. The best modem was a 39 parallel tone modem (Mil-Std-188-110?) and 2400 BPS. On HF it sounded funny...robotic like...and while it did work on about the same SNR as a ~S3 SSB signal ...the SNR had to be about 10 dB, it worked much better on VHF and UHF FM as well as UHF AM. In Jan-Feb 1990, after Operation Just Cause, I got to play with a Harris Mil-Std-188-110? modem and DV at 2400 BPS AND 4800 BPS. The 2400 bps DV still sounded a bit robotic but worked quite well at S2-S3 signals and even when the SNR was at or I think slightly below 10 dB. The modem had ALE and provided a SNR figure and my old ham radio ear figured an S2-3 signal. When we switched to 4800 bps, the DV sounded just like the individual speaking over a telephone...better than SSB voice but it required a slightly better SNR. Data with the TacTerm 39 tone modem was really good...text came through at about a page a minute with a signal that you could hear. When the signal got down close to the noise...where you had to strain to hear it, the throughput went down to maybe 20-30 lines per minutebut still near 100% copy (could have been typing errors). The actual computer software was KA9Q NOS running on a BIG military laptop computer. When we went to the Harris modem and 2400 BPS/4800 BPS, the copy at 2400 BPS was about the same with a good signal but better than the TacTerm with lower qualitity signals. 4800 bps screemed unless the signal got below 10 dB SNR or so. During Operations Desert Shield and Desert Storm, the U.S. Marine Corp used a Hughes RT-1209 and Harris AM-6545A 400 watt amplifier to make up the GRC-193A (http://www.nj7p.org/millist/pic/grc-193.gif) used in some of the last productions Jeeps and Humvees. Most were using a 15-16 ft fold over whip. The whip went up just about 18" higher then the Humvee top and then tilted over and ran horizontal the remainder of the length. This provided a good NVIS antenna radiation pattern. The Marine Corp did connect the Harris MIL-STD-188-110x modem to the GRC-193 and used a computer to send data from the field back to their command center. For digital voice I believe that some units used the Navy's version of the TacTerm and some may have been using the later ITT MinTerm DV unit. The TacTerm (KY-57) can accept signal fades of up to 12 seconds without losing synchronization with the transmitting station. I never noticed any delays or words that were not understandable using the TacTerm or MinTerm or Harris Modem using LCP-10 and UG-??? encryption unit. There were of course a second or two between transmissions, but certainly not enough to prevent artillary spotting or fire control. The PRC-109/GRC-193 systems were used at least in 1985 and perhaps before with the TacTerm. The TacTerm was used in the Viet Nam war on HF SSB, VHF and UHF AM and as far as I know without problems. The C-130s tracking and Navy vessel captured by North Korea used Tacterm's on HF and the crew of the C-130 never mentioned to me that there were communications using the TecTerm. So when the Marine Corp have problems with DV must have been shortly after the capture of the USS Pubelo which I believe was in 1968. A good reference on the ANDVT modem may be _HF modem evaluations for the Advanced Narrowband Digital Voice Terminal (ANDVT)_ by Chase, D.; Bello, P. A.; Boardman, C.; Pickering, L.; Pinto, R. published in Nov 1978 Abstract: "During this program, the specifications for the ANDVT HF modem have been refined and detailed evaluation and simulation of the new technical features within this modem have been conducted. These include a multiple-tone signal detection format with an adaptive threshold, a multiple-tone/multiple-stage Doppler estimation algorithm, a matched filter frame estimation algorithm utilizing PN correlation properties, a low-rate error-correction coding approach for protection of the KG sync sequences, an error-correction coding approach specifically designed to protect the critical speech parameters, use of soft-decision (channel measurement) information obtained from the demodulator, and decision-directed Doppler tracking utilizing information from all data tones. The analytical and simulation results provide the desirable result that the preamble can be successfully received at a lower SNR than is required for the reception of high-quality 2400-b/s digitized voice." Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Wednesday, October 11, 2006 2:17 AM To: digitalradio@yahoogroups.com Subject: [digitalradio] Re: Digital Voice: Some thoughts after one week. Some more info: I found a paper that describes some tests done with 2.4Kbps and 1.2kbps voice transmission over HF paths. It sounds like the 1.2 kbps gives useable voice quality. I talked to a friend who had done some research for the
Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
I can't help you either. A bit hard to mount a computer vs AOR DV modem in a mobile set up like I have done. John, W0JAB At 08:41 AM 10/11/2006, you wrote: Paul, Have you found a significant difference between the quality and robustness of the AOR product vs. WinDRM? __._,_.___ Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) SPONSORED LINKS Ham radio Ham radio antenna Ham radio store Digital voice Digital voice recorder mp3 Your email settings: Individual Email|Traditional Change settings via the Web (Yahoo! ID required) Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe __,_._,___
[digitalradio] Re: First DRM Reception
--- In digitalradio@yahoogroups.com, Tony <[EMAIL PROTECTED]> wrote: > > Jim > > > You need to mute the MIC audio on your sound card. That will stop the WinDRM > digital signal from making it to your PC speakers and mixing with the > decoded voice. Once it starts to decode, WinDRM will playback the audio into > your sound card speakers. > > In WinDRM, click on SOUNDCARD, OPEN MIXER, RX INPUT. The windows Mixer will > open. Now click PROPERITES, PLAYBACK, then OK. On the microphone slider > click MUTE. Well, thanks, but... The soundcard mixer stuff doesn't seem to work under WINE. I guess I have to use the native Linux mixer. And my soundcard has only one output, not separate line and speaker outputs. That's why I think I need another sound card. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] QRV Digital Voice 14236.0 1430z
All: QRV DV 14236.0 --1430z (Oct 11). Will be here for an hour or two. Tony KT2Q Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
On Oct 11, 2006, at 06:41, KV9U wrote: > Paul, > > Have you found a significant difference between the quality and > robustness of the AOR product vs. WinDRM? Sorry Rick, I have never used WinDRM. Mainly due to the fact that I do not use Windows as an OS platform. Also, it draws less power than a computer, I can take it on the go mobile much easier, and I don't miss the computer spaghetti between computer - radio. > > It seems to me that external hardware would become obsolete if worked > about as well as the free sound card product. That's the way it's always been. > > This is not unlike the situation that has occured with hardware modems > for Pactor, Amtor, etc. While a few (very few) might use them for > casual > contacts, it is actually very rare now. At one time you would have no > trouble finding others to link with. > > With the hardware solutions though, you lock yourself into a fixed > codec > that is very likely to change due to constant technology improvements. > DiD AOR make some provisions for updates. Honestly, I don't know enough to fully answer this question. I know with the AOR ARD9800 digital voice modems, we the users are able to flash upgrade the units ourselves from files supplied to us by AOR. All we needed was a computer, the file, and a single cable to the ARD9800 unit. During the first year or two, AOR released Flash files every few months. It seems that they settled on that last flash release about 2 years back when they started releasing the smaller ARD9000 units, and now the ARD9000 mk2. I believe the reason they settled down releasing new Firmware versions was in part due to the fact that the ARD9000 required the owner to ship it into the factory in order for it's firmware to be upgraded. To what extent can the AOR units be upgraded, I'm not quite sure. You might try asking Taka at AOR USA. Good question though. Have Fun ! Paul Metzger KQ6EH - > > 73, > > Rick, KV9U Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: WinDRM Hiss??? PROBLEM SOLVED!!!!!!
Paul, Have you found a significant difference between the quality and robustness of the AOR product vs. WinDRM? It seems to me that external hardware would become obsolete if worked about as well as the free sound card product. This is not unlike the situation that has occured with hardware modems for Pactor, Amtor, etc. While a few (very few) might use them for casual contacts, it is actually very rare now. At one time you would have no trouble finding others to link with. With the hardware solutions though, you lock yourself into a fixed codec that is very likely to change due to constant technology improvements. DiD AOR make some provisions for updates. 73, Rick, KV9U Paul Metzger wrote: >I've been calling CQ for the past couple hours on 40m. But then again, >I'm using the AOR DV units, not WinDRM. > >Sorry. > >Paul Metzger > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Re: Digital Voice: Some thoughts after one week.
It was my understanding that the QAM-4 modulation was used for the text transmission and you needed to use at least QAM-16 for the voice. How many bps can you get through with QAM-4? If LPC doesn't work at 1200 bps, then what other codec do you suggest? Even MELP (which is a type of LPC) normally was based upon a 2400 bps speed was it not? And apparently it works OK at 1000 bps? 73, Rick, KV9U cesco12342000 wrote: > >A codec withh 1000bit/sec would allow qam-4 modulation, and improve >the robustness to "useful" levels. Tests with a 1200 bit/sec LPC >codec have been negative (bad intellegibility). > > > > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] HI - A quick Introduction
Hi guys I'm new here and thought i would introduce myself: I am Tim Holmes, W8TAH -- ive been an extra for a couple years now. My interests are quite varied in amateur radio. Contesting (more for fun than for scores) casual DX chasing, meteor scatter, rtty, psk, and pretty much anything else fun -i dont do homebuilding or boatanchors (if i can avoid it) my base rig is an ICOM 706mk2G and i have a decent computer and rig-blaster combination set up. Im mostly available in the evenings after work till about 8:30 or 9:00pm Eastern time. IM always happy to try to work skeds etc Have an Awesome day TIM W8TAH Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Digital Voice: Some thoughts after one week.
> The WinDRM specification is very sketchy .. Well,... you are invited to provide a better one. > but the FEC is not > described. The interleaving of the pilots and overhead data is > described but not the interleaving of the voice data. It says "This document describes the DIFFERENCE of mode HAM to the official broadcast DRM standard". That means everithing not described is like the official broadcast DRM standard. FEC and interleave is exactly like broadcast. More, its the same code used in the DREAM DRM software. > I will have to have a conversation with one of the speech codec > designers I work with. A codec withh 1000bit/sec would allow qam-4 modulation, and improve the robustness to "useful" levels. Tests with a 1200 bit/sec LPC codec have been negative (bad intellegibility). Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [digitalradio] Kantronics KAM
OK thanks for that, didn't know that,,and yes PMR 446, ian.David Ackrill <[EMAIL PROTECTED]> wrote: ian parkinson wrote:>> I think the Kam etc are great, I had thought of hooking a couple up on > 466 Mhz and leave messages in a neighbours M.box for playing chess.Do you mean PMR446?If so, don't let the authorities catch you, as it's not legal to use anything other than voice on PMR446...(See http://www.ofcom.org.uk/radiocomms/ifi/licensing/classes/business_radio/information/ofw57/#content where it says "PMR 446 is a handportable, short-range, voice-only communication system. It provides a basic but effective radio service for both business and non-business users, and is ideal for providing communication over short distances (e.g. within office buildings, factories and building sites). Please note that it is for speech transmissions *only*.")There's discussion of 'Digital' PMR446, but that seems to be about digital audio, not AX.25.Dave (G0DJA) Try the all-new Yahoo! Mail . "The New Version is radically easier to use" The Wall Street Journal __._,_.___ Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) SPONSORED LINKS Ham radio Ham radio antenna Ham radio store Digital voice Digital voice recorder mp3 Your email settings: Individual Email|Traditional Change settings via the Web (Yahoo! ID required) Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe __,_._,___
[digitalradio] Re: Digital Voice: Some thoughts after one week.
Some more info: I found a paper that describes some tests done with 2.4Kbps and 1.2kbps voice transmission over HF paths. It sounds like the 1.2 kbps gives useable voice quality. I talked to a friend who had done some research for the military back in the '80s on digital voice transmission over HF. He said that the state of the art back then was about 2.4Kbps but there was a technique developed for decoding the speech into text with a very limited vocabulary for tactical operations - around 300 words - and sending the words with minimum coding required for the limited vocabulary. The transmitted data was then reconstructed into speech at the receiving end. The data rates achieved with this method were as low as 300 bps. There were a few problems with this method, though. First it introduced substantial delays due to the processing required for the speech recognition. Second, the Aussies got very upset when their speech came out the other end of the link with a midwestern accent. :) Finally, when attempts were made to apply this method to an application for the Marines for fire control communications, the Marines were unable to come up with a 300 word vocabularly that didn't contain profanity or obscenities so the project was killed. Seriously, long distance HF propagation imposes some very challenging problems with long fades that can only be overcome with long interleaving of the data which creates long delays in the transmission. I will continue to study the issue and report any interesting ideas that show promise for weak signal digitzed voice communications. Ed --- In digitalradio@yahoogroups.com, "Ed Hekman" <[EMAIL PROTECTED]> wrote: > > --- In digitalradio@yahoogroups.com, Tony wrote: > > > > Ed wrote: > > > > > Are there any communications engineers in this group that can > > > give us some idea whether a useable quality digitized voice can > be > > > sent over a 2.5 KHz wide HF channel with SNR comparable to or > less > than > > > what is required for analog voice? > > > > I was thinking about this today Ed. I'd sacrifice a bit of voice > qaulity for > > better SNR performance. > > > > WinDRM defaults to the MELP codec and I was wondering if the SPEEX > or LP-10 > > offer an improvement in SNR performance? > > > > Tony KT2Q > > Tony, > > The key to better weak signal performance will be primarily in how > the data is sent over the air. Observing the signal for digital > SSTV on 20M has been very interesting. Often a hole in the spectrum > can be observed as it moves across the spectrum. It takes out about > 20% of the spectrum and has a time span at one frequency of around a > second. The packaging of the data must be done with enough > redundancy spread throughout the spectrum so it can be recovered in > spite of these spectrum holes. On 80M atmospheric noise tends to > have short impulses that take out the entire signal for much shorter > periods of time - much less than a second. To mitigate this, the > data redundancy must be spread over time so the data can be > recovered in spite of a complete loss of signal for a few > milliseconds. > > Of course adding redundancy means reducing the data rate for the > encoded voice data. This would probably require some adjustments to > the voice coding algorithm. With cellular signals, although the > maximum data rate may be 8K bps, the effective rate is usually less > than 1/2 that due to the fact that speech is not a constant signal - > there are holes in it for short periods of time during which no data > needs to be sent. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
