Re: [digitalradio] Re: RM-11306 Rant
John ... Like you I have lived and worked in many countries with voluntary bandplans... THEY WORK VERY WELL... or I would not be suggesting them... But us US Hams love to keep our blinkers on and ignore the successes in the rest of the world... We hate to tryanything new.. and just because it works well everywhere else, it cant work in the provincial old USA It's that kind ofinnovative thinking that put GM and the rest of the US Car industry in the hole it currently is in... But your wisdom is falling on deaf ears on this reflector as they are totally focused on the anti-Pactor 3 rantings and ant-Internet rantings...to listen to the postive results from the rest of the world or to even consider the harm the current regulation have done to stiffle innovation in the USA. __Howard S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LAWebsite: www.ky6la.com "No Good Deed Goes Unpunished""Ham Antennas Save Lives - Katrina, 2003 San Diego Fires, 911" - Original Message - From: John Bradley To: digitalradio@yahoogroups.com Sent: Friday, January 27, 2006 7:46 PM Subject: Re: [digitalradio] Re: RM-11306 Rant To me as an outsider, ie not a citizen of the USA, it's both interesting and confusing as to why Hams in the US feel that they need structure and many regulations in order to make the bandplan work. There are collectively a whole whack of Europeans who are making a voluntary plan work, as well as us Cannucks it comes down to an issue of respect among members of the Ham community there is ample room for all users, including the dreaded pactor 3 stations, so I can't understand why the desire for rules and regulations in a bandplan? So far the rest of the world seems satisfied with a voluntary plancertainly worth a second look. Keep in mind that it is easier to have more regulations brought in if the need is there, rather than trying to convince the FCC that more regulations should be dropped.. the old inertia theory of government. John VE5MU 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 Visit your group "digitalradio" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[digitalradio] Re: knock it off RANT
--- In digitalradio@yahoogroups.com, Ross [EMAIL PROTECTED] wrote: Can the Moderator, please stop this rubbish. Can US hams please realise that this is a worldwide group and it is read by hams around the world. If you want to discuss your internal US problems do it somewhere else. Ross ZL1WN Hear Hear. This has got to be the most long winded, irrelevant, parochial thread ever. And it all comes down to lack of trust. Americans do not trust each other to comply with a Gentlemans Agreement. It's sad. Brad VK2QQ 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/ * 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: RM-11306 Rant
I for one want to start experimenting with digital voice technologies on HF... There is a lot of really cool stuff out there to try that could give us 100% voice copy withS/N in the-db ranges. It would be really cool to copy voice when my CW friends could no longer copy code like we now do with OliviaBut most of these new technologies are currently screwed up with the current regulations. __Howard S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LAWebsite: www.ky6la.com "No Good Deed Goes Unpunished""Ham Antennas Save Lives - Katrina, 2003 San Diego Fires, 911" - Original Message - From: N6CRR To: digitalradio@yahoogroups.com Sent: Friday, January 27, 2006 8:05 PM Subject: [digitalradio] Re: RM-11306 Rant --- In digitalradio@yahoogroups.com, Paul L Schmidt [EMAIL PROTECTED]... wrote: I really LOVE it when people tell me why I think what I think. The scenario I mentioned is *EXACTLY* what I would be doing if it were legal. What's plain silly is having that scenario prohibited simply because one it involves switching from voice to digital. (By the way, I'm a member of MARS, and that's EXACTLY how we handle a lot of traffic. It's efficient and effective.)PaulI'm sure that given the high volume of traffic on the MARS netshandles now day, the switching from voice to digital or other modes ofoperation works well for you and MARS, great!I however don't see a crying demand for this mode of operation onAmateur frequencies , and I am of the belief that most of the noisegenerated in support of this change is based on being able to givemore spectrum to delivery of email, and other digital data productsover scarce HF spectrum resources. I don't see the demand for it now,and frankly I don't think that Amateur Radio is about providing analternative to conventional internet services. Maybe HF frequencies allocated to MARS operations are a good place fora trial of this sort of shared MARS voice and Digital email and otherdata content delivery system? Cheers! 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 Visit your group "digitalradio" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[digitalradio] Re: RM-11306 Rant
--- In digitalradio@yahoogroups.com, Danny Douglas [EMAIL PROTECTED] wrote: I havent seen most of the new European band plans but ill bet my bottom dollar they do not forbid the use of SSB in the 7-7.1 portion of 40 meters. It would only make sense to do so, since they now have 7.1-7.2 and can easily send SSB there and clear the lower portion of the band for the narrow mode, and also get away from the idiotic splits.Bet it doesnt happen. You didnt do it, and they wont do it. Danny, They don't operate exclusive SSB above 7100 for valid reasons. Here's one - In January Adventist World Radio commenced a new transmission to the Middle East, from Germany, on 7115kHz at 250kW. Here in Australia, that signal is S9+. Would you like to compete with that? No, I thought not. Brad VK2QQ 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/ * 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: RM-11306 Rant
Kim, I implore you and others who have the bought the ARRL's statement that mode/emission type regulation has stifled experimentation hook, line, and sinker to educate yourself about this issue! Probably 90 - 99% of the digital modes today use J2- or J3- emissions. The only thing I don't know for sure is how many RTTY stations use AFSK and how many use true FSK that is implemented with separate oscillators. I am not aware of any work being done in the digital arena at this time that requires a new emission/mode type definition, either here or in Europe! Consequently, emission/mode regulation IS NOT stifling any experimentation. I'll give you and others a challenge, name one digital mode that is in use elsewhere on HF that has been restricted in the US because of emissions/mode type regulations! Another challenge to you! Please discuss what restrictions on experimentation will bandwidth regulations provide? This type of regulation will incur its own set of restrictions. Which will be more restrictive, emissions or bandwidth? Jim WA0LYK --- In digitalradio@yahoogroups.com, Kim Aiken [EMAIL PROTECTED] wrote: Good Post Doctor. Amateur radio started and will continue to be about the exploration and experimentation with new technologies. Hams worlwide are developing new operating modes daily. Band regulation by mode is outdated the moment someone devises a band plan. RM-11306 is not the correct solution, but it appears to be the most politically acceptable plan in the view of the ARRL. It is better than we have now and the doctor is correct that in the world of political compromise it is a good first step. Kim - AC7YY 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/ * 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: RM-11306 Rant
Brad, You need to educate yourself about the FCC petitions here. One of the current petitions will let hams operate SSB anywhere. If that is approved, you can bet the 7-7.1 portions will become a favorite place for US SSB stations. Do you and others want to compete with them? Jim WA0LYK --- In digitalradio@yahoogroups.com, Brad [EMAIL PROTECTED] wrote: --- In digitalradio@yahoogroups.com, Danny Douglas [EMAIL PROTECTED] wrote: I havent seen most of the new European band plans but ill bet my bottom dollar they do not forbid the use of SSB in the 7-7.1 portion of 40 meters. It would only make sense to do so, since they now have 7.1-7.2 and can easily send SSB there and clear the lower portion of the band for the narrow mode, and also get away from the idiotic splits.Bet it doesnt happen. You didnt do it, and they wont do it. Danny, They don't operate exclusive SSB above 7100 for valid reasons. Here's one - In January Adventist World Radio commenced a new transmission to the Middle East, from Germany, on 7115kHz at 250kW. Here in Australia, that signal is S9+. Would you like to compete with that? No, I thought not. Brad VK2QQ 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/ * 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] Digital voice on HF
There are some who have experimented with the expensive adapters, and some who have tried the voice mode of WinDRM. I am not sure how cool this stuff is at this time. I have not had any luck finding much activity, nor others who would be willing to try it out. When I have asked about it, some have said it is very disappointing since it doesn't work if signals are not strong. The main advantage of digital voice seems to be the possibility of a wider audio spectrum, but like most digital modes that require a high throughput (such as voice), the signals drop out completely if the signal goes below a threshhold level. Maybe it will someday be possible to improve digital voice to equal SSB, but I wonder if it is technically feasible to do this considering the practical limitations of physics. The understanding that I have is that digital VHF/UHF voice is used primarily due to the narrower bandwidth compared to FM modes. But against SSB? Comparing CW with digital keyboard modes is a different situation because the amount of data going through is much smaller in order to print well on the receiving end. And if it really slows down enough, it can get through ... but not in real time. And that is the limitation that I see with voice, in that voice is not very effective if not in real time. But there is nothing preventing the experimentation of digital voice at this time from what I have read of the rules. The problem here in the U.S. is the ability to send data on a voice channel. It is sort of legal by some interpretations, but not really clearly legal. The idea that a digital picture (image) is OK to send on a voice channel, but other data are not is so absurd as to defy logic. Sometimes you might want to use SSB analog voice and then send an image, either analog or digital. This is done all the time in the voice portion of the bands. But some times you might want to send a data file. Further, even if bandwidth proposals go through, they are still making it sound like this problem will not necessarily be corrected. They may still require analog and digital to be kept in separate areas with bandplans. This really concerns me. 73, Rick, KV9U Dr. Howard S. White wrote: I for one want to start experimenting with digital voice technologies on HF... There is a lot of really cool stuff out there to try that could give us 100% voice copy with S/N in the -db ranges. It would be really cool to copy voice when my CW friends could no longer copy code like we now do with Olivia But most of these new technologies are currently screwed up with the current regulations. __ Howard S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA Website: www.ky6la.com http://www.ky6la.com No Good Deed Goes Unpunished Ham Antennas Save Lives - Katrina, 2003 San Diego Fires, 911 - Original Message - *From:* N6CRR mailto:[EMAIL PROTECTED] *To:* digitalradio@yahoogroups.com mailto:digitalradio@yahoogroups.com *Sent:* Friday, January 27, 2006 8:05 PM *Subject:* [digitalradio] Re: RM-11306 Rant --- In digitalradio@yahoogroups.com mailto:digitalradio@yahoogroups.com, Paul L Schmidt [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]... wrote: I really LOVE it when people tell me why I think what I think. The scenario I mentioned is *EXACTLY* what I would be doing if it were legal. What's plain silly is having that scenario prohibited simply because one it involves switching from voice to digital. (By the way, I'm a member of MARS, and that's EXACTLY how we handle a lot of traffic. It's efficient and effective.) Paul I'm sure that given the high volume of traffic on the MARS nets handles now day, the switching from voice to digital or other modes of operation works well for you and MARS, great! I however don't see a crying demand for this mode of operation on Amateur frequencies , and I am of the belief that most of the noise generated in support of this change is based on being able to give more spectrum to delivery of email, and other digital data products over scarce HF spectrum resources. I don't see the demand for it now, and frankly I don't think that Amateur Radio is about providing an alternative to conventional internet services. Maybe HF frequencies allocated to MARS operations are a good place for a trial of this sort of shared MARS voice and Digital email and other data content delivery system? Cheers! 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)
Re: [digitalradio] Digital voice on HF
Could it be that we need to look at a compression
protocol that would allow full-range audio to travel
via noise-resistent digital modulation without
hogging lots of spectrum?
From a non-engineer's perspective it sure would seem
that such is possible.
There is the much-delayed digital AM-BC technology
wherein which the noise that harms AM-BC popularity
vs FM-BC is remediated. That gets us half way there!
I know that many thought further compression of images
and text unlikely then along cam djvu.
doc
KV9U wrote:
There are some who have experimented with the expensive adapters, and
some who have tried the voice mode of WinDRM. I am not sure how cool
this stuff is at this time. I have not had any luck finding much
activity, nor others who would be willing to try it out. When I have
asked about it, some have said it is very disappointing since it doesn't
work if signals are not strong.
The main advantage of digital voice seems to be the possibility of a
wider audio spectrum, but like most digital modes that require a high
throughput (such as voice), the signals drop out completely if the
signal goes below a threshhold level.
Maybe it will someday be possible to improve digital voice to equal SSB,
but I wonder if it is technically feasible to do this considering the
practical limitations of physics. The understanding that I have is that
digital VHF/UHF voice is used primarily due to the narrower bandwidth
compared to FM modes. But against SSB?
--
~~
Thanks! 73, doc kd4e
|_|___|_|
| | | |
{|
/\ {|
/ \ {|
/\{|
/ @ \ {|
| |~_||
| -| ||
\ # http://bibleseven.com/kd4e.html
KD4E =
West Central Florida
~~~
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[digitalradio] Spot digital frequencies
Because we have so many active digital hams on this group, is it possible that we could outline specific spot calling/operating frequencies for the digital modes on bands that are not as common to find digital signals? I never have come up with a very clear understanding of the best places to operate on some of the bands. Mainly I base it upon what I have observed as a PSK31 watering hole frequency (3580, 7070, 14070) and if I want to try other modes (wider bandwidth) then move a few KHz up from there. Two bands that I would think would work well for digital would be 160 and 30 meters but I rarely hear anyone on there with a digital signal except for Pactor stations that I assume are sending e-mail traffic from the internet. Is it possible to have an updated Digitalradio list of frequencies? The Dgiband.doc in our files section seems out of date to me and does not fully match up with what is current operating practices. Examples here in U.S.: The ARRL bandplan on 160 meters shows digital 1.800 to 1.810 and yet many digital lists show PSK around 1.838 The ARRL bandplan on 40 meters shows digital (RTTY) starting at 7.080 and yet it seems like PSK31 is mostly 7.070 I never have much luck on 30 meters when I call. Is it possible that we might make 10.130 the spot frequency for digital on 30 meters and then if there is more activity, just move up? And I don't mean PSK31 as I rarely operate that mode and prefer wider modes with much more robust performance. 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/ * 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: RM-11306 Rant
This message from WA7NWP has been forwarded to the Digipol reflector http://groups.yahoo.com/group/digipol Please reply , if you wish, via that message group. Andy K3UK The ARRL proposal, as proposed, will limit data bandwidths to about 3 KHz. The real world (search on commercial HF data systems) has realized that often (usually?) wider is better and is developing hardware and systems accordingly. The ARRL proposal will lock us (U.S. amateurs) into using late 1990's technology. 73, Bill - WA7NWP 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/ * 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: Spot digital frequencies
If there is someone on 10.130, then of couse you would move away from that busy frequency and that probably means moving higher up a few KHz to the next available clear frequency. I had to take a break from writing this message because, of all things, I heard a station around 10.130 on a digital mode. I was thinking it was Olivia due to the sound, but the bandwidth did not fit quite right with the markers for any of the 500 Hz modes and of course I could not decode it. Finally, we contacted each other on CW, and Rod, KN3ZOG, explained he was sending with DominoEX. So I brought up the separate Domino program since I don't have the EX version on MultiPSK. Signals did not move the S meter very much but were very good copy from a CW point of view. The decode was not perfect but we may not have been tuned quite right either. I find the tuning to be a bit different I think and not as easy to use as in my regular program. Since it does not provide for keying the CI-V on my ICOM, it was difficult to manually do the switching. I noticed that on both ends, I was causing considerable carriage returns making it nearly impossible to read, so switched to sentence mode. Then it would stop TX and switch to RX when it caught up with my keyboarding. Since it is a fast mode, that was pretty often:) I still prefer MFSK16 or Olivia for casual keyboarding, but if Domino got some FEC and even better, some ARQ, it would be most interesting to see how it would perform. 73, Rick, KV9U Jerry W wrote: Rick, One problem with 10.130 in the evening, a very strong FSK signal (foreign government or commercial origin?) difficult to filter it out at least in South St Paul, MN. Jerry - K0HZI 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/ * 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] Digital voice on HF
KV9U wrote: U.S. is the ability to send data on a voice channel. It is sort of legal by some interpretations, but not really clearly legal. The idea that a digital picture (image) is OK to send on a voice channel, but other data are not is so absurd as to defy logic. Sometimes you might want to use SSB analog voice and then send an image, either analog or digital. This is done all the time in the voice portion of the bands. But some times you might want to send a data file. Re: The absurdity of differentiating the content of semi-random digital bits I agree. What about embedded metadata in a digital picture? JPEG, etc. files can have all kinds of metadata in a header indicating various aspects of the exposure apparatus (in the case of a digital picture). At what point does image data become just plain data, and does all data fall under the ancient FCC designation RTTY? -- J. Lance Cotton, KJ5O [EMAIL PROTECTED] http://kj5o.lightningflash.net Three Step Plan: 1. Take over the world. 2. Get a lot of cookies. 3. Eat the cookies. 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/ * 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 TV (off topic)
I'm with Alan. When I went from analog cable to digital satellite, the difference has remarkable , even to old eyes. The difference between digital satellite and HD satellite is not as great... still some but not as obvious. HD satellite approaches the quality of a good DVD player. . - Original Message - From: Alan NV8A To: digitalradio@yahoogroups.com Sent: Saturday, January 28, 2006 11:27 AM Subject: Re: [digitalradio] Re: Digital TV (off topic) On 01/28/06 10:35 am kd4e wrote: I like the idea of a widescreen TV and have begun looking around for one. For the life of me, I don't see the $5000 plasma screen pictures (in stores) as a whole lot better than the picture I currently get from my satellite provider (standard definition). I looked carefully at a 42 inch DTV and a 42 HDTV , Why not buy a decent refurbished video projector for a fraction of the price? with a $3000 price diference, I could see NO difference. The salemans said he saw a big difference, maybe I am digitalblind. Andy K3UK The saleman is, of course, "seeing" the display through his commission "eyes".I am not in the market for a big-screen TV, but I can even see the difference between Standard-Definition analog and High-Definition (1080i) digital programming on our 26" CRT TV.Alan NV8A No virus found in this incoming message.Checked by AVG Free Edition.Version: 7.0.375 / Virus Database: 267.14.23/243 - Release Date: 1/27/06 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 Craft hobby Hobby and craft supply Icom ham radio Yaesu ham radio YAHOO! GROUPS LINKS Visit your group "digitalradio" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[digitalradio] RF Digital Protocol Education
I want to experiment with digital protocols in ham radio by starting with the PC soundcard. I understand some of the basics like filters and FFT. I even have some of them working in code (C++). I do not know how to proceed from the basics into demodulating an audio signal into bits. For instance, I am playing with the VHF packet protocol which use 1200 and 2200 hz signalling. I enter the samples for a single 1200 hz cycle into the FFT array. The FFT shows a peak at around 1000 hz. The FFT arrayis 2048 samples long filled with 0s except for the 1 cycle of 1200 hz which is 40 samples at the rate of 48000 samples per second. If I put 4 cycles in the FFT array I get 1195 hz which is correct. Hanning or Hamming Windows do not help. I have looked at some of the available source but am missing the insight I need for proceeding further. Any suggestions on how to proceed further? Any suggestions on books or web sites that address communications DSP at this level? How about an email reflector where I can ask questions of DSP gurus? -73- Rud K5RUDARES AEC Montgomery County, TX 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 Visit your group "digitalradio" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[digitalradio] Re: Spot digital frequencies
Ron, Have had a few QSO's on PSK and MFSK around 10.138 evenings. Could try DominoEX there if someone wants to try, maybe after sunset, which is around 2315z and two minutes later every day. Wanted to mention the 10.130 FSK station in the evenings, think it is heard over most of North America in the evenings. Jerry - K0HZI --- In digitalradio@yahoogroups.com, W4LDE-Ron [EMAIL PROTECTED] wrote: Just slide up around 10.138 and a center frequency for the audio at or about 1000HZ, for the DX stay up above 10.140 when running a 500HZ width mode like Olivia. Sometimes you will run into a packet signal so try and give them some room, 30 meters is a great band but like you said there isn't to much activity on that band. I have called CQ's until I am blue in the face, next time I'll try using the transceiver hi. Maybe we can get some more digital activity on 30 meters, I have heard RTTY, MFSK and PSK with very little from MT63 and Olivia. Maybe DominoEX can provide some fun. Ron W4LDE 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/ * 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] Hampal
I finally acquired hampal and have it loaded. I did manage to see hampal and end in the waterfall (how they do that ? ! ) but no picture received yet. Seems that 14233 is quiet for a calling frequency. Is there mich activity for digital SSTV? Maybe a 40M calling frequency ? Andy K3UK 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/ * 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] Digital modes FAQ?
I wonder if we should consider a group project? I'm think a digital modes FAQ could be helpful and perhaps several people here could volunteer to write sections of it. I'm thinking of the following topics (each one would have a few sub-questions and answers). What Are Digital Modes ? (what good are they? Why bother?, which mode is best?)) What software do I need ? How do I Interface a radio and PC? (what kind of radio do I need?) How do I Receive signals? How do I transmit? What is PSK31? (what does it sound like? , where do I find it ? What is QPSK? (what does it sound like? , where do I find it ? What is PSK63? (what does it sound like? , where do I find it ? What is RTTY? (what does it sound like? , where do I find it ? What is AMTOR (what does it sound like? , where do I find it ? What is Packet (what does it sound like? , where do I find it ?, What is MFSK (what does it sound like? , where do I find it ? What is Olivia (what does it sound like? , where do I find it ? What is PACTOR (what does it sound like? , where do I find it ? What is SSTV (what does it sound/look like? , where do I find it ? What is ALE (what does it sound like? , where do I find it ?, is it a digital mode? What is THROB (what does it sound like? , where do I find it ? Anymore ? 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/ * 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] Digital voice on HF
Look at it this way. The coding used for most VOIP over the internet is about as good as it gets today. Most of it provides toll grade quality, e.g. 300-3000hz bandwidth. That doesn't provide high fidelity nor is it conducive to high intelligibility (think your 2.8khz SSB is high intelligibility? many systems, such as those used for fire annunciation require 6khz or higher bandwidths). Most of the VOIP I have seen works *marginally* over a dial up connection. Lot's of hits and dropouts. What would it take to provide a similar connection on HF? Assume you'll need *at least* a 30kb data channel. Most of the protocols I have seen today will get you about 2bits/hz on HF. That means you'll need at least a 15khz wide data channel. Solutions such as the AOR system decrease this down to the 3khz range but in doing so incur a huge penalty in signal to noise ratio capability. I believe most of the UHF digital voice units used to be 13khz units although the newer stuff is about 7khz. Since these systems are designed to be used in a much different environment than HF, I'm not sure just how well they would convert. Let's assume their transmission schemes are usable on HF during moderate to weak-signal conditions. So, where are we? It looks like you would need somewhere between a 7khz and 15khz channel to implement digital voice on HF in a manner that will insure its widespread adoption. Now, take a close look at those bandwidths? Do you suppose that *any* of the HF equipment you have in your shack today will work at those bandwidths? Even if you put in a 15khz SSB filter in your Icom 751a, it is doubtful that the audio and IF chains are designed for use with a signal this wide. It is quite likely that totally new equipment designed to a much higher standard will be needed. So the amateur community will be left with a BIG, *B* *I* *G* cost to convert to a digital format that may or may not even approach SSB in efficiency. Consider: Most of our HF bands are crowded already -- regardless of what the nay-sayers would have you believe. Try to find a spot to call CQ on 80m or 40m some evening. Do we want to go from a mode that operates in a 2.1khz to 2.8khz bandwidth for one that requires 7-15khz or more than 3 times the bandwidth? The total spectrum efficiency measurement of users satisfied would be cut by at least a third - not a good thing. Consider: The typical male voice has a power crest factor of around 25. A 100watt transmitter carrying a voice signal has an average power output of about 4 watts. That's one big reason why a conversation in the Northeast, one in Florida, and one in Kansas can all be in progress on 3920khz at 2300UTC and everything is copacetic. The other big reason is the syllabic and phrase pauses in human speech which allow listeners to distinguish between speakers. The digital voice modes, on the other hand, would have power crest factors ranging from 2 to 6. That means average power outputs of 50 watts to 16 watts or something between 4 to 10 times the power output of a SSB signal using analog voice. And no pauses in the signal! What does this mean? Lots more interference, fewer users per frequency because propagation stacking won't be as large, and fewer users satisfied during heavy usage loads. So spectrum efficiency goes down even further. So what do we have? Higher bandwidths-lower spectrum efficiency. More interference-lower spectrum efficiency. Higher costs-lower economic efficiency. More equipment needed-lower technical efficiency. So the question that should be asked isn't can we do it on HF. It should be do we want to do it on HF? That's one thing that is very, very wrong with the ARRL proposal. They have done exactly *no* technical analysis of anything! Their claims that Digital is coming! Digital is coming! have exactly zero merit as nearly as I can determine. Unless they know of something better than APCO 25 that is coming down the pike - they don't have a leg to stand on with their claims. And if they *DO* know of something, they should be letting the Dept of Homeland Security know because they are handing out a LOT of *our* dollars for local systems to convert to systems like apco25. Don't fall into the old debate trap of someone using the argument its new so it must be better!. Ask them to show you why it is better! You won't get anything from the ARRL, I can assure you that - I have tried over and over and over again and just get the same, tired platitudes. tim ab0wr On Saturday 28 January 2006 12:17, John Bradley wrote: I'm not a techie but i know what works. Being active in a Ground search and Rescue team, on occaison we use the local police service radios, rather than 2M HT for comms. The new system the police service installed within the past year is 800MHZ digital encrypted.. using these on a repeater, we had amazing results a long ways out from the repeater site.. llike upwards of
Re: [digitalradio] Digital modes FAQ?
Q15X25 On Saturday 28 January 2006 14:37, obrienaj wrote: Anymore ? 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/ * 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] Digital voice on HF
Tim's points are accurate when it comes to the current practical use of digital voice on HF. I would mention that when the ARRL did a product review on the new ICOM digital HT's, they were pretty honest with comments on the robotic audio and if I recall from a later review, the fact that the audio quality was good right up until drop out. At the same time, if you had used it in analog, it would have been very noisy, it would have been useable with analog for a slightly weaker signal. And this was for comparing analog FM with digital. SSB should be able to operate with a much weaker signal than digital voice on HF. From what I can tell, you can operate SSB voice just about to a zero S/N ratio but digital voice requires quite a bit better signal, perhaps closer to 10 db. Slow modes, such as keyboard text can work -10 to even -15 or more in some cases. No matter what anyone says about wide HF modes that are a lot wider than an SSB BW, there is simply no support for such modes. If DSB AM was invented tomorrow, we all know it would never be allowed and is only being grandfathered in because so few ever use it. 73, Rick, KV9U Tim Gorman wrote: Don't fall into the old debate trap of someone using the argument its new so it must be better!. Ask them to show you why it is better! You won't get anything from the ARRL, I can assure you that - I have tried over and over and over again and just get the same, tired platitudes. tim ab0wr 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/ * 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] Hampal
In the Midwest U.S. there is a active group on 7.173 that does most all of the digital image modes. obrienaj wrote: I finally acquired hampal and have it loaded. I did manage to see hampal and end in the waterfall (how they do that ? ! ) but no picture received yet. Seems that 14233 is quiet for a calling frequency. Is there mich activity for digital SSTV? Maybe a 40M calling frequency ? Andy K3UK 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/ * 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 on HF
I just did a quick internet search and here is what I came up with.
commercial nbfm (old) occupied bndwth 40 kHz
commercial nbfm (current) occupied bndwth 15 kHz
commercial nbfm (new) occupied bndwth 12.5 kHz
FCC hoped for (planned) occupied bndwth 6.25 kHz
apco-25 digital voice (now) occupied bndwth 12.5 kHz
apco-25 digital voice (planned) occupied bndwth 6.25 kHz
cellular TDMA occupied bndwth 30 kHz
cellular GSMoccupied bndwth 300 kHz
cellular CDMA occupied bndwth 1.25 MHz
cellular Nextel occupied bndwth 25 kHz
cordless phones occupied bndwth 500 kHz
broadcast FMoccupied bndwth 200 kHz
As you can see, many of the digital voice implementations require
extremely wide signals when compared to current HF modes. Not likely
we'll see digital voice on HF allowed a wider bandwidth than SSB under
the ARRL plan!
Jim
WA0LYK
--- In digitalradio@yahoogroups.com, John Bradley [EMAIL PROTECTED] wrote:
I'm not a techie but i know what works.
Being active in a Ground search and Rescue team, on occaison we use
the local police service radios, rather than 2M HT for comms. The new
system
the police service installed within the past year is 800MHZ digital
encrypted.. using these on a repeater, we had amazing results a
long ways out from the repeater site.. llike upwards of 40KM over
flat terrain. The voice quality is excellent... no idea what the
bandwidth was, though. Typically the copy would be either 100% or
nothing, nothing in between, again not sure if this was the encryption
process or the digital voice which would cause that. These units
worked equally well on simplex when needed . This is a Motorola system.
I wonder how readily this technology would adapt to HF? Is there
any software out there to experiment with?
- Original Message -
From: kd4e
To: digitalradio@yahoogroups.com
Sent: Saturday, January 28, 2006 10:33 AM
Subject: Re: [digitalradio] Digital voice on HF
Could it be that we need to look at a compression
protocol that would allow full-range audio to travel
via noise-resistent digital modulation without
hogging lots of spectrum?
From a non-engineer's perspective it sure would seem
that such is possible.
There is the much-delayed digital AM-BC technology
wherein which the noise that harms AM-BC popularity
vs FM-BC is remediated. That gets us half way there!
I know that many thought further compression of images
and text unlikely then along cam djvu.
doc
KV9U wrote:
There are some who have experimented with the expensive
adapters, and
some who have tried the voice mode of WinDRM. I am not sure how
cool
this stuff is at this time. I have not had any luck finding much
activity, nor others who would be willing to try it out. When I
have
asked about it, some have said it is very disappointing since it
doesn't
work if signals are not strong.
The main advantage of digital voice seems to be the possibility
of a
wider audio spectrum, but like most digital modes that require a
high
throughput (such as voice), the signals drop out completely if the
signal goes below a threshhold level.
Maybe it will someday be possible to improve digital voice to
equal SSB,
but I wonder if it is technically feasible to do this
considering the
practical limitations of physics. The understanding that I have
is that
digital VHF/UHF voice is used primarily due to the narrower
bandwidth
compared to FM modes. But against SSB?
--
~~
Thanks! 73, doc kd4e
|_|___|_|
| | | |
{|
/\ {|
/ \ {|
/\{|
/ @ \ {|
| |~_||
| -| ||
\ # http://bibleseven.com/kd4e.html
KD4E =
West Central Florida
~~~
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)
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Re: [digitalradio] Re: Digital TV (off topic)
As a former user of a BUD (big ugly dish) of 10' diameter and analog TV signals, I can say for sure that there is absolutely no comparison with respect to video quality between the broadcast quality (eg., 34 dB SNR) video signal as received by the BUD and those transmitted by typical digital satellite providers such as Dish and DirectTV. The analog signal wins hand over heels. Now that almost all TV is sent digitally, the difference no longer stands out like it did back when. The HDTV signals, however, are much better on either type of display than were the analog broadcast band quality pictures. Except when the signal breaks up, for whatever reason into those gross digital blocks. I have never been a fan of analog cable due to the p-poor quality control. The SNR of most analog signals barely meets minimums at the user's TV set. My 2 cents. 73, Chuck, AA5J At 12:25 PM 1/28/2006, you wrote: I'm with Alan. When I went from analog cable to digital satellite, the difference has remarkable , even to old eyes. The difference between digital satellite and HD satellite is not as great... still some but not as obvious. HD satellite approaches the quality of a good DVD player. . - Original Message - From: mailto:[EMAIL PROTECTED]Alan NV8A To: mailto:digitalradio@yahoogroups.comdigitalradio@yahoogroups.com Sent: Saturday, January 28, 2006 11:27 AM Subject: Re: [digitalradio] Re: Digital TV (off topic) On 01/28/06 10:35 am kd4e wrote: I like the idea of a widescreen TV and have begun looking around for one. For the life of me, I don't see the $5000 plasma screen pictures (in stores) as a whole lot better than the picture I currently get from my satellite provider (standard definition). I looked carefully at a 42 inch DTV and a 42 HDTV , Why not buy a decent refurbished video projector for a fraction of the price? with a $3000 price diference, I could see NO difference. The salemans said he saw a big difference, maybe I am digitalblind. Andy K3UK The saleman is, of course, seeing the display through his commission eyes. I am not in the market for a big-screen TV, but I can even see the difference between Standard-Definition analog and High-Definition (1080i) digital programming on our 26 CRT TV. Alan NV8A -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.0.375 / Virus Database: 267.14.23/243 - Release Date: 1/27/06 Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipolhttp://groups.yahoo.com/group/Digipol (band plan policy discussion) SPONSORED LINKS http://groups.yahoo.com/gads?t=msk=Ham+radiow1=Ham+radiow2=Craft+hobbyw3=Hobby+and+craft+supplyw4=Icom+ham+radiow5=Yaesu+ham+radioc=5s=101.sig=NStjWgsFtXmQaGrYd1LT5wHam radio http://groups.yahoo.com/gads?t=msk=Craft+hobbyw1=Ham+radiow2=Craft+hobbyw3=Hobby+and+craft+supplyw4=Icom+ham+radiow5=Yaesu+ham+radioc=5s=101.sig=RIfve-PXBTtOVJV48uzEVQCraft hobby http://groups.yahoo.com/gads?t=msk=Hobby+and+craft+supplyw1=Ham+radiow2=Craft+hobbyw3=Hobby+and+craft+supplyw4=Icom+ham+radiow5=Yaesu+ham+radioc=5s=101.sig=Qz1juq9z5gSL9A5AR8aLNAHobby and craft supply http://groups.yahoo.com/gads?t=msk=Icom+ham+radiow1=Ham+radiow2=Craft+hobbyw3=Hobby+and+craft+supplyw4=Icom+ham+radiow5=Yaesu+ham+radioc=5s=101.sig=_InABMy_m6lCJHFiWobT2wIcom ham radio http://groups.yahoo.com/gads?t=msk=Yaesu+ham+radiow1=Ham+radiow2=Craft+hobbyw3=Hobby+and+craft+supplyw4=Icom+ham+radiow5=Yaesu+ham+radioc=5s=101.sig=9lSLfMHwXV-vjTYO4qyD8wYaesu ham radio -- YAHOO! GROUPS LINKS * Visit your group http://groups.yahoo.com/group/digitalradiodigitalradio on the web. * * To unsubscribe from this group, send an email to: * mailto:[EMAIL PROTECTED][EMAIL PROTECTED] * * Your use of Yahoo! Groups is subject to the http://docs.yahoo.com/info/terms/Yahoo! Terms of Service. -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.23/243 - Release Date: 1/27/2006 Regards, ChuckM mailto:[EMAIL PROTECTED] -- http://worldconnect.rootsweb.com/~clmayfield http://freepages.genealogy.rootsweb.com/~mayfield 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/ * 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] K3UK Telnet Address
http://telnet.dxcluster.info/ Check here under 2nd call area.. - Original Message - From: Thomas Giella KN4LF To: a Digital Radio eGroup Sent: Saturday, January 28, 2006 7:48 PM Subject: [digitalradio] K3UK Telnet Address Anyone know the exact address to type into the telnet window in MixW to access the K3UK Digital Telnet? I guess the port is 4?! Also my WWV data is no longer updating in the DX Cluster window. I have /dxs/wwv250.html? in the WWV Page box and it seems to be the correct address?! 73,Thomas F. Giella, KN4LFLakeland, FL, USAGrid Square EL97AW[EMAIL PROTECTED] Proof Of God Through Science: http://www.cosmicfingerprints.com/audio/newevidence.htmKN4LF Amateur SWL Radio History: http://www.kn4lf.comKN4LF MF Radio Propagation Theory Notes: http://www.kn4lf.com/kn4lf8.htm 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 Visit your group "digitalradio" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[digitalradio] Digital Mode Operating Frequencies (?)
I'm not quite sure I have all the frequencies down pat for operating the various digital modes, so asking for some inputs from the group on where people operate. PSK 31 is pretty simple, .070 seems to be the place to be on 15, 20 and 40, 3.580 on 80. Olivia is usually found around 14.106 or there about in 1Khz mode, but what about lower rates like 500 Hz? 40 and 80 are a question mark also. DominoEX seems so new that there is not a convention for where people working it hang out. Anyone? 73 Steve 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/ * 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] 5600 baud circuit in 2400hz
Question for the digital experts: How do you get a 5600 baud circuit to fit into a 2400hz bandwidth? tim ab0wr 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/ * 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: 5600 baud circuit in 2400hz
If there is redundancy in the data -- e.g. images, or natural language text -- loss-less compression before transmission and decompression after reception might get you there. 73, Dave, AA6YQ --- In digitalradio@yahoogroups.com, Tim Gorman [EMAIL PROTECTED] wrote: Question for the digital experts: How do you get a 5600 baud circuit to fit into a 2400hz bandwidth? tim ab0wr 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/ * 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: 5600 baud circuit in 2400hz
Respectfully, you are talking about compressing the content. That won't help with cramming a 5600 baud circuit into a 2400hz bandwidth. It might help send more content faster - making a slower circuit look like a 5600 baud circuit, but it won't help put a 5600 baud circuit into a 2400hz bandwidth. Anybody else got any ideas? tim ab0wr On Saturday 28 January 2006 19:51, Dave Bernstein wrote: If there is redundancy in the data -- e.g. images, or natural language text -- loss-less compression before transmission and decompression after reception might get you there. 73, Dave, AA6YQ --- In digitalradio@yahoogroups.com, Tim Gorman [EMAIL PROTECTED] wrote: Question for the digital experts: How do you get a 5600 baud circuit to fit into a 2400hz bandwidth? tim ab0wr 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/ * 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] Digital modes FAQ?
Obrienaj wrote: What is ALE (what does it sound like? , where do I find it ?, is it a digital mode? What is THROB (what does it sound like? , where do I find it ? Anymore ? Nobody has discussed the mode Hellscriber it is a weird one! -- John MW3JNV 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/ * 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] Digital voice on HF
There are voice encoding schemes that require much less. I've experimented with this codec (for example), and found it quite good even at 3k bits per second: http://www.hawksoft.com/hawkvoice/ It's not lossless mind you, but quite intelegible and almost natural sounding. Artie Lekstutis KC2MFS What would it take to provide a similar connection on HF? Assume you'll need *at least* a 30kb data channel. Most of the protocols I have seen today will get you about 2bits/hz on HF. That means you'll need at least a 15khz wide data channel. 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/ * 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/
