[digitalradio] Re: ALE400 - Narrow band ALE mode now available
You've forgotten about the nasty reality of AGC and receiver overload. For what you say to be true, one must disable the AGC and the receiver must have the dynamic range/overload capability to not fold with the wider bandwidth. If they did we would never need narrow filters. Many rigs have no off AGC position. The only other choice becomes reducing the RF gain. That eliminates the weak one you're trying to hear. A narrower filter can mitigate the AGC problem as well as improving the S/N ratio. The sound card digital filtering comes after all these stages in the chain. It simply cannot make up for receiver generated junk. The dynamic range is not set by the sound card but by the weakest part of the chain-- the RX. A SDR radio where the sound card is the IF is a different story entirely-- if the front end sound card and down converter circuitry is linear and can handle strong sigs. There are indeed sound cards that claim a 120db dynamic range. 73 de Brian/K3KO --- In digitalradio@yahoogroups.com, Vojtech Bubnik [EMAIL PROTECTED] wrote: --- In digitalradio@yahoogroups.com, Brian A alsopb@ wrote: 1) Using a 200 Hz filter instead of 400 or 500 Hz filter gives a 3db S/N ratio improvment-- PSK or RTTY. It's guaranteed. It is not. Using narrower filter will reduce total noise and out of channel QRM, lowering dynamic range requirements for MF, AF and A/D stages. If the chain has enough dynamic range, it does not matter, which filter you use. Each software PSK31 decoder contains narrow DSP filter just after A/D What really matters is S/N after this digital filter, which is independent of MF filter bandwidth. In other words, all the extra baggage (bandwidth) is generally just extra weight with no robust benefit. There are physical laws telling that one needs less energy to transport the same information, if he increases channel bandwidth. 73, Vojtech OK1IAK
[digitalradio] Re: ALE400 - Narrow band ALE mode now available
Patrick, I applaud all the experimenters out there trying to push the envelope. Meeting personal goals is a really healthy part of the hobby. It doesn't really matter if that goal become an integral part of ham radio or not. Experimention for its own sake is good. Also, thanks for the info. As one who uses digital only to communicate and DX, I'm not sure what all this buys me-- or the average ham. For starters: 1) Using a 200 Hz filter instead of 400 or 500 Hz filter gives a 3db S/N ratio improvment-- PSK or RTTY. It's guaranteed. 2) There are actually many people to talk to. 3) 100% copy is not needed in most QSO's. If someone's rig displays on the screen as a TS-851 instead of a TS850, it really doesn't matter. Similarly with eyeball QSO's with someone, nobody copies all words 100%. Let's face it, even with a few errors stuff relayed by ham radio is miles ahead in accuracy compared to what comes out from the mass media. 4) One can alraady work stations down to the noise floor. Actually, I've had many RTTY contacts below the noise floor by augmenting the print with aural copy of calls/reports. In other words, all the extra baggage (bandwidth) is generally just extra weight with no robust benefit. Sure some selected applications may need it. Until we find a way to access extra frequency blocks in some parallel universe, narrower is better. Unfortunately, a lot (but not all) of the hype about emergency communications is just a smoke screen to forward particular personal agendas. If ham radio existed to keep the price of pork high, you'd have people saying their invention does that too. It is interesting to note that so much of this stuff is hyped as THE ANSWER to emergency communications. I see the same claim by the AMSAT people and many other groups for their modes (e.g. D*). Of course each isn't. Each is one of many possibilities. The more obsure you make the mode, the fewer people will be proficient at its use. The smaller the pool of emergency repsonders we would have. Hype isn't the answer to expanding the pool. It's got to be accepted by a wide swath of users. It has to age for many years in the pot of real experience. Instead we're seeing the digital flavor of the week. I guess after 40 years of hype for various hame radio adgendas, I've grown tired of hearing them, become a skeptic and rather cynical of new and improved. How about a shift in paradigm? Look around and see what modes most people use and adopt that? It doesn't have to be just digital! Wouldn't that provide the largest possible pool of responders and equipment? Realize that our contribuition is for the window of time between time zero of an event until when the official channels get running. One is dealing with maximizing the probability of having trained ham radio personnel and equipment actually at or near a particular location. It seems that big numbers matter. Interesting comment about the usage of digital freq's there. The PSK area of the digital 20M band is absolutely wall to wall with stations over here. 40M is similarly crowded especially at night with PSK and RTTY. I can't imagine trying to use a wide IF filter on 40M for any digital mode. 73 de Brian/K3KO --- In digitalradio@yahoogroups.com, Patrick Lindecker [EMAIL PROTECTED] wrote: Hello Brian and all, I don't think there is to compare RTTY with ALE400. The objectives are really different and there is nothing common. ALE and ALE400 permits a rich system of communications with different possibilities (see my paper ALE and ALE400 easy). Without speaking of PC ALE and Mars ALE which offer really a lot of interesting possibilities. Neither ALE nor ALE400 have for objectives to replace RTTY. The huge advantage of RTTY is to be simple and universal, but that's all. RTTY technology is old. His performance is very poor. The bandwidth is not optimized (for optimized RTTY, choose RTTY with 23 Hz of shift). However, it matches very well quick QSO in contest. Necessarily, modern modes will need more bandwidth because: * you need to code your data (to finally gain in the minimum S/N), * more bandwidth permits a diversity in frequency which helps to make the transmission robust (in general all modern modes as MFSK16, Olivia, ALE have a diversity in time and in frequency). About the bands crowded. For this side of the ocean, the digital bands don't seem very crowded except during contests. It seems there are widely enough room for 400 Hz bandwidth transmissions. 73 Patrick - Original Message - From: Brian A To: digitalradio@yahoogroups.com Sent: Friday, November 02, 2007 1:29 PM Subject: [digitalradio] Re: ALE400 - Narrow band ALE mode now available I'm not trying to be a pain in the butt, honest. If one put ALE400 and RTTY side by side for the average ham ALE-400 would be a hard sell. Same speed in twice the bandwidth. I guess one may conclude all
[digitalradio] Re: ALE400 - Narrow band ALE mode now available
--- In digitalradio@yahoogroups.com, Brian A [EMAIL PROTECTED] wrote: 1) Using a 200 Hz filter instead of 400 or 500 Hz filter gives a 3db S/N ratio improvment-- PSK or RTTY. It's guaranteed. It is not. Using narrower filter will reduce total noise and out of channel QRM, lowering dynamic range requirements for MF, AF and A/D stages. If the chain has enough dynamic range, it does not matter, which filter you use. Each software PSK31 decoder contains narrow DSP filter just after A/D What really matters is S/N after this digital filter, which is independent of MF filter bandwidth. In other words, all the extra baggage (bandwidth) is generally just extra weight with no robust benefit. There are physical laws telling that one needs less energy to transport the same information, if he increases channel bandwidth. 73, Vojtech OK1IAK
Re: [digitalradio] Re: ALE400 - Narrow band ALE mode now available
Brian, It depends upon what you, or the average ham, are looking for. If you want to do contesting, and if the inertia stays with RTTY, then that is what will remain as a popular mode. A couple of decades ago, many of us found RTTY to be quite interesting and even built TU's to get on HF. Then along came the boxed hardware/firmware ARQ modes of Amtor and then Pactor and Clover II and moved the bar. This made it possible for nearly 100% data transmission accuracy for the first time on amateur radio. While you would not use these connected modes for contesting, due to the slow exchange, they worked well for messaging and casual contacts. These modes were fairly expensive and not widely adopted, but they were a niche interest, no different than other niche interests in our amazingly broad hobby. More recently, the sound card modes caused the next big change in digital radio communications. In terms of sensitivity, RTTY is more limited. It can certainly go below zero dB S/N, but some of the newer digital modes can go far below that. So where you would get no communication at all with RTTY, you would have solid print with say, PSK31 or MFSK16. The extra baggage of interleaving, coding, redundancy, etc., allow for much improved robustness, far beyond what RTTY can do. Now we have the next big change which is sound card ARQ technology. This was first implemented with SCAMP about three years ago but abandoned by the Winlink 2000 developer. Not long ago, one ham was able to develop the PAX mode and then the PAX2 mode which gave us an inkling of what is possible with sound card and digital ARQ. That same ham has been able to use an older technology, using the 8FSK125 waveform from ALE and adapt it for ARQ with the full ASCII character set and make it available in a multimode software program at no cost. Then he was able to go even farther and develop an 8FSK50 mode (ALE 400) that is much narrower, but is also much more sensitive and robust and is more appropriate in the text digital portions of the ham bands. It sounds as if you are not very supportive of, or even interested in emergency communications, however, there are many of us who find that part of ham radio to be the most interesting and we are always on the look out for modes and equipment that are inexpensive and therefore would be used by other hams and allow us to provide better communications than we have thus far been able to do. You are right that we do need to focus on a common denominator for emergency communications. We continue to do this through tactical HF and VHF voice which is an absolute must. But some believe we can and should do more than the minimum and thus we look to new technologies to do things that we could not do before. RTTY is definitely not one of those technologies, but ARQ sound card modes can be. There are so many new modes and technologies competing at the same time (and likely more to come) that it will take some years for radio amateurs to sift and winnow and find those that have the right mix of cost, adoption, and use. But I think it is fair to say that it is also the most exciting time for the digital modes and related technologies since I was first licensed in 1963. 73, Rick, KV9U Brian A wrote: As one who uses digital only to communicate and DX, I'm not sure what all this buys me-- or the average ham. For starters: 1) Using a 200 Hz filter instead of 400 or 500 Hz filter gives a 3db S/N ratio improvment-- PSK or RTTY. It's guaranteed. 2) There are actually many people to talk to. 3) 100% copy is not needed in most QSO's. If someone's rig displays on the screen as a TS-851 instead of a TS850, it really doesn't matter. Similarly with eyeball QSO's with someone, nobody copies all words 100%. Let's face it, even with a few errors stuff relayed by ham radio is miles ahead in accuracy compared to what comes out from the mass media. 4) One can alraady work stations down to the noise floor. Actually, I've had many RTTY contacts below the noise floor by augmenting the print with aural copy of calls/reports. In other words, all the extra baggage (bandwidth) is generally just extra weight with no robust benefit. Sure some selected applications may need it. Until we find a way to access extra frequency blocks in some parallel universe, narrower is better. Unfortunately, a lot (but not all) of the hype about emergency communications is just a smoke screen to forward particular personal agendas. If ham radio existed to keep the price of pork high, you'd have people saying their invention does that too. It is interesting to note that so much of this stuff is hyped as THE ANSWER to emergency communications. I see the same claim by the AMSAT people and many other groups for their modes (e.g. D*). Of course each isn't. Each is one of many possibilities. The more obsure you make the mode, the fewer people will be proficient at its use.
RE: [digitalradio] Re: ALE400 - Narrow band ALE mode now available
Yes, the laws of physics do get in the way. They say that wider bandwidth is the technique to use. The trick in that situation is that the bandwidth is used by multiple users at the same time. Everyone is background noise to the other guy. Rud Merriam K5RUD ARES AEC Montgomery County, TX http://TheHamNetwork.net -Original Message- It just seems to me that to replace existing technology, the newer stuff has to be able to do all the old technology could do and much more in the same or less bandwidth. I'm not seeing this in these digital modes. Yep, laws of physics do tend to get in the way. Those interested in what can be done if the bandwidth were available should read the proceedings of the AMSAT meeting held this month in Pittburgh. They are talking about a geosyncronous satellite with 6MHz of bandwidth available. Supposedly being able to be reached with 5 watts and a 60cm dish. They think this is the future of emergency communications. 73 de Brian/K3KO
[digitalradio] Re: ALE400 Narrow band ALE mode now available
I'm not trying to be a pain in the butt, honest. If one put ALE400 and RTTY side by side for the average ham ALE-400 would be a hard sell. Same speed in twice the bandwidth. I guess one may conclude all the bells and whistles of ALE, ARQ etc are doubling the bandwidth requirements. One can copy RTTY with a 200 HZ filter. I doubt one can do the same with ALE-400. Are the benefits really worth doubling the bandwidth? Put another way, halving the number of stations possible for a given band. Perhaps so, but certainly only for a narrow slice of the ham hobbiest needs. We need narrower bandwidths not wider bandwidths for real progress with the real life crowded bands. I think that is why PSK has worked so well. Anybody pushing for wider bandwidths seems to be swimming against the current. I want to point out the old fashioned analog mode of SSB this weekend had at least one station making 10,000 DX QSO's in a 48 hour period. This was the bottom of the sunspot cycle with incredible QRM. It just seems to me that to replace existing technology, the newer stuff has to be able to do all the old technology could do and much more in the same or less bandwidth. I'm not seeing this in these digital modes. Yep, laws of physics do tend to get in the way. Those interested in what can be done if the bandwidth were available should read the proceedings of the AMSAT meeting held this month in Pittburgh. They are talking about a geosyncronous satellite with 6MHz of bandwidth available. Supposedly being able to be reached with 5 watts and a 60cm dish. They think this is the future of emergency communications. 73 de Brian/K3KO --- In digitalradio@yahoogroups.com, Steinar Aanesland [EMAIL PROTECTED] wrote: What is your point? LA5VNA Setinar Brian A skrev: So one gets the 60wpm of 170Hz shift RTTY for a 400 Hz bandwidth? 73 de Brian/K3KO --- In digitalradio@yahoogroups.com mailto:digitalradio%40yahoogroups.com, Mark Thompson wb9qzb@ wrote: ALE400 Narrow band ALE mode now available Patrick F6CTE has announced that a narrow band version of the popular Automatic Link Establishment (ALE) software is now available. On the HFLink Yahoo group he writes: For those interested in doing ALE and ARQ FAE using a narrow bandwidth (400 Hz), I have derived from the standard ALE a new ALE with a bandwidth of 400 Hz (instead of 2000 Hz) and which is called 'ALE400'. This ALE system has exactly the same functions as the standard ALE (in Multipsk) except that the: bandwidth is 400 Hz (so ALE400 can be used where 500 Hz modes are permitted) the speed (and consequently the text throughput) is 2.5 slower, no fix frequency (it is as MFSK16, Olivia or DominoEX modes) the S/N is 5 dB better: - 9 dB for AMD messages and Unproto - 11.5 dB (- 13.5 dB with many repetitions) for ARQ FAE For ARQ FAE, it has been added a compression system using a modified IZ8BLY (Nino) MFSK Varicode. So the text throughput (in ALE400) is typically 60 wpm (up to 107 mpm in bilateral and 63 characters frames). This test version in a ZIP test package is available in my site http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP (copy and paste this address in Internet Explorer (or equivalent) Net address field). It contains the Multipsk test version, the help files (in English and French) and the specifications (in English) of the ARQ FAE mode (version 1.4). Create a temporary folder (C:\TEST, for example), unzip the files in it and start C:\TEST\TEST\Multipsk.exe (the auxiliary files will be created automatically). For the contextual help, click on the right button of the mouse, with the focus over the mode button ALE400. Use also the button hints (wait a fraction of second over a button). Hints: if you are the Master (initiator of the CQ): confirm the RS ID transmission in Options (to permit an automatic tuning for other Hams), check Master on the Mode panel and, afterwards, push the button CQ if you are the Slave (the Ham who answers): push the button RS ID detection (to permit your automatic tuning on CQ), check Slave on the Mode panel and, afterwards, push the button Answer. Both will push on the AFC button. Note: it rings on successful connexion (on both sides). 73 Patrick Related URL's HFLink Yahoo Group http://groups.yahoo.com/group/HFLink http://groups.yahoo.com/group/HFLink HFLink http://www.hflink.org/ http://www.hflink.org/ MultiPSK Website http://f6cte.free.fr/ http://f6cte.free.fr/ ALE400 Software - A Test version has been available at http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP but like all test software it could be frequently updated. __ Do You
Re: [digitalradio] Re: ALE400 Narrow band ALE mode now available
Hi Brian, At 08:29 AM 11/2/2007, you wrote: I'm not trying to be a pain in the butt, honest. Neither is my reply meant to be anything other than pointing out the obvious. We need narrower bandwidths not wider bandwidths for real progress with the real life crowded bands. I think that is why PSK has worked so well. Anybody pushing for wider bandwidths seems to be swimming against the current. Patrick's efforts on FAE ARQ and ALE400 are an excellent example of taking Military communications standards and deriving solutions for Amateur Radio applications tailored to both the equipments being used by Radio Amateurs and within reason, to the parameters being demanded as well, he did not have to take the time and effort to provide ALE400 in response to those calling for narrower bandwidth, I certainly would not have bothered doing so, I applaud his efforts! For daily, casual Amateur Radio QSO's PSK and all modes down to CW ( which more new Amateurs should be using) are just fine, great actually, with two good CW ops if they can hear each other the message will be passed, but the top speeds under the best of conditions are pale in comparison to modern digital FEC and ARQ protocols. I want to point out the old fashioned analog mode of SSB this weekend had at least one station making 10,000 DX QSO's in a 48 hour period. This was the bottom of the sunspot cycle with incredible QRM. For the given speed that a Phone SSB contact can be made, 1.8Khz band width is about as narrow as you can go and still be intelligent, for meaningful traffic passing and not DX contacts you would NEVER see 10,000 contacts in 48 hours on SSB, taking into account a typical ECOM message and band conditions, from a single operator based SSB Phone station, you would be really lucky to get off 600 and with shifts of changing operators. It just seems to me that to replace existing technology, the newer stuff has to be able to do all the old technology could do and much more in the same or less bandwidth. I'm not seeing this in these digital modes. Yep, laws of physics do tend to get in the way. Yes, for digital speed you need bandwidth, its that simple. SSB Phone and AM Phone take up a lot of bandwidth for very little in the way of speed, or for that matter accuracy and operator fatigue has a negative affect on both parameters during an ECOM event. Those interested in what can be done if the bandwidth were available should read the proceedings of the AMSAT meeting held this month in Pittburgh. They are talking about a geosyncronous satellite with 6MHz of bandwidth available. Supposedly being able to be reached with 5 watts and a 60cm dish. They think this is the future of emergency communications. All well and good, but the focus here is HF digital communications for ECOM, at least that is my focus and when you start talking about this aspect of ECOM we can of course any existing technology, however for the best throughput and error free delivery I can not see much less than 2Khz BW and ARQ protocols being used to achieve greater than 300 baud operation, the adaptive PSK ARQ stuff that I am work with in MARS exceeds 800 baud uncompressed already using the PC Sound Device Modem (PCSDM) within a 2Khz BW, wether those with a narrow BW focus come around or not, these wave forms on coming on the air from countries outside the U.S, here the out of date FCC rules need to change to bring it and other technology to the U.S. Amateur Radio bands to enable the U.S. Amateur Radio Service to benefit from the application of the PCSDM in support of ECOM and not continue regulate U.S. Amateurs to using expensive, proprietary hardware modems when we could be achieving desire results via the PCSDM. /s/ Steve, N2CKH 73 de Brian/K3KO
[digitalradio] Re: ALE400 Narrow band ALE mode now available
So one gets the 60wpm of 170Hz shift RTTY for a 400 Hz bandwidth? 73 de Brian/K3KO --- In digitalradio@yahoogroups.com, Mark Thompson [EMAIL PROTECTED] wrote: ALE400 Narrow band ALE mode now available Patrick F6CTE has announced that a narrow band version of the popular Automatic Link Establishment (ALE) software is now available. On the HFLink Yahoo group he writes: For those interested in doing ALE and ARQ FAE using a narrow bandwidth (400 Hz), I have derived from the standard ALE a new ALE with a bandwidth of 400 Hz (instead of 2000 Hz) and which is called 'ALE400'. This ALE system has exactly the same functions as the standard ALE (in Multipsk) except that the: bandwidth is 400 Hz (so ALE400 can be used where 500 Hz modes are permitted) the speed (and consequently the text throughput) is 2.5 slower, no fix frequency (it is as MFSK16, Olivia or DominoEX modes) the S/N is 5 dB better: - 9 dB for AMD messages and Unproto - 11.5 dB (- 13.5 dB with many repetitions) for ARQ FAE For ARQ FAE, it has been added a compression system using a modified IZ8BLY (Nino) MFSK Varicode. So the text throughput (in ALE400) is typically 60 wpm (up to 107 mpm in bilateral and 63 characters frames). This test version in a ZIP test package is available in my site http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP (copy and paste this address in Internet Explorer (or equivalent) Net address field). It contains the Multipsk test version, the help files (in English and French) and the specifications (in English) of the ARQ FAE mode (version 1.4). Create a temporary folder (C:\TEST, for example), unzip the files in it and start C:\TEST\TEST\Multipsk.exe (the auxiliary files will be created automatically). For the contextual help, click on the right button of the mouse, with the focus over the mode button ALE400. Use also the button hints (wait a fraction of second over a button). Hints: if you are the Master (initiator of the CQ): confirm the RS ID transmission in Options (to permit an automatic tuning for other Hams), check Master on the Mode panel and, afterwards, push the button CQ if you are the Slave (the Ham who answers): push the button RS ID detection (to permit your automatic tuning on CQ), check Slave on the Mode panel and, afterwards, push the button Answer. Both will push on the AFC button. Note: it rings on successful connexion (on both sides). 73 Patrick Related URL's HFLink Yahoo Group http://groups.yahoo.com/group/HFLink HFLink http://www.hflink.org/ MultiPSK Website http://f6cte.free.fr/ ALE400 Software - A Test version has been available at http://f6cte.free.fr/MULTIPSK_TEST_28_10_2007.ZIP but like all test software it could be frequently updated. __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
