[digitalradio] Dayton SDR forum speakers sought
On Friday, May 14, I am the moderator (and speaker) at the SDR forum at the 2:30 PM - 5 PM session. I have two speakers (Scotty on openhpsdr, and I speak on general SDR topics). I need to fill out this time and this leaves at least 1.5 hours to fill. I would like to get this settled as soon as possible. Let me know if you are interested in making a presentation. Also, FYI, I will be the AMSAT/TAPR banquet speaker on Friday night. In addition to my forum, SDR, paper delivery with Joel Harrison, work in Flex booth, etc. this will be one of the busiest Dayton's for me in years. I look forward to seeing many of you. Bob McGwier N4HY
[digitalradio] A new mode for PSK31, Attention gmfsk users on Linux
Attention gmfsk users. I am putting a new PSK31 mode in gfmsk. I need some test guinea pigs. In this case, there will be one, two, , N orthogonal trellis coded PSK31 signals. Each tone will have 4 or 4.5 dB of coding gain over the PSK31 but will otherwise work the same. When Peter did the QPSK Viterbi decoder on a constraint length five code, he didn't realize that you were going to realize essentially zero coding gain over PSK31 with that arrangement. Not to mention the fact that to decode with anything like full gain, you need to wait 15-20 bit times to get the job done. With this Trellis code, it is 8 states or possibly 16 states (testing will tell) and will decode in 1/2 or 3/4 as many bits. By going to N parallel tones, we can choose between higher speed or more robustness. More robustness will come at the cost of decoding delay for the interleaver with concatenated TCM and Reed Solomon interleaved data. I will first release the single tone TC-PSK31 and then go to N in parallel. The thing that Peter got so right was the source coding with the varicode. Please send me private email if you are or quickly can be an gmfsk user on Linux. This will be one of my talks at DCC in Hartford. Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you're going to be crazy, you have to get paid for it or else you're going to be locked up. Hunter S. Thompson
[digitalradio] Flex Radio gathering and presentation
From John Basilotto, W5GI, at Flex: Subject: FlexRadio Systems Social and Presentation at Dayton Date: Saturday May 19 Time. 7:45 PM until 11:00 PM Place: University of Dayton, Kennedy Union, Barrett Dining Room ( 1st floor) Program: formal program starts at 8:15 PM. Presentation by Gerald Youngblood: SDR update and the FLEX-5000. Flexi Awards and prize drawing immediately afterwards. Complimentary soft drinks and pretzels. Program will be broadcast on Team Speak courtesy of Eric Ellison. Parking: all university parking lots can be used. See map at http://admission.udayton.edu/virtour/Campus_map_text.swf Directions from various points at Dayton http://www.udayton.edu/Visiting+UD/ Strip maps will be available at the FlexRadio booths 315-317. Please note this is the only presentation that Gerald will make during the Hamvention. Hope to see you there. -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you're going to be crazy, you have to get paid for it or else you're going to be locked up. Hunter S. Thompson
[digitalradio] FCC Report and Order on Software and Cognitive Radio
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-07-66A1.pdf -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you're going to be crazy, you have to get paid for it or else you're going to be locked up. Hunter S. Thompson
Re: [digitalradio] Noise Reduction and the digital modes
Patrick Lindecker wrote: Hello Andy and all, I don't think NR must be a so good idea for digimodes. Because, it can be seen as non-linear filter. I disagree on the transfer function. It is an adaptive linear filter. Since it does not mix two tones in the passband, it can't be nonlinear. However, it does indeed introduce serious phase and amplitude distortion on the signals. This is not the way to better copy. These Widrow type/ LMS adaptive filters, in single sample update, or block adaptive form are intended TO AID THE HUMAN FATIGUE FACTOR in listening to noise or interfering tones. We agree that they are no good for digital modes. In that type of filter, the next sample is calculated, knowing the previous symbols and guessing what is the most probable symbol if nothing change (a sort of no more set of information condition)... You are surely going to produce interference between symbols: the decoding will be not so good and the necessary synchronization will be more difficult because the difference between one symbol and the following will be reduced (i.e the difference between two successive symbols will be softened). But it would be interesting to experiment on calibrated signals and different speeds (from the PSKAM10 to ALE or PSK220F). 73 Patrick Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
Re: [digitalradio] Noise Reduction and the digital modes
Patrick Lindecker wrote: Hello Robert, TKS for the correction. I returned to my books. LMS filters are in general linear (LMS-FIR), however they can also be in a recursive structure (LMS-IIR). Patrick, thanks for your reply. An IIR filter (with an FIR component and a feedback component) is still a linear filter. Even if you are adapting it, it is still a linear transfer function for each and every sample. The transfer function is Sum(Outputs * Feeback_coeffients) = Sum(Inputs * FeedForward_ Coefficients is linear on both sides and this is an IIR. The adaptation is funky and may be a nonlinear adaption, but at each sample instant a linear filter is applied to all samples in its delay lines and so no mixing can occur. Now, if you are thinking about decision directed LMS equalizers, where you make a hard decision as the output, that is most decidedly nonlinear. You do not hard limit the output of your NR filter! The typical AGC circuit in a receiver is more nonlinear than any LMS based NR filter, FIR, IIR, etc. could ever be. Bob We agree that they are no good for digital modes. Yes the a priori is not very favourable. 73 Patrick 73's Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
Re: [digitalradio] Can I get a rig with MORE?
Walt: Frank, Eric, and I have specfically answered all of your questions about the Linux support. It is completely controllable under Linux now especially for those who have no need for fancy radio GUI's. For those that need GUI's there ARE GUI's and more will be coming. Roger Rehr has painted the road with crayola crayon especially for you: http://www.nitehawk.com/w3sz but the Linux code does not have the polished presentation of the Windows version of code AND IT DOES NOT SUFFER FROM ITS LIMITATIONS. It is poised to take off now. There are several approaches to take such as dttsp-shell (available from Edson Pereira) or the java GUI done by John Melton or usSDR gui done by Jonathan Naylor. Frank and I are not interested in doing this GUI work. We are interested in support anyone who wants to do the GUI work. Bob N4HY (coauthor DttSP with AB2KT) DuBose Walt Civ AETC CONS/LGCA wrote: Peter, IMHO, the SDR-1000 has some of the best specs. out and is the most configurable transceiver on the market. I have seen the insides of the transceiver several times and the construction looks good. But note that it is only controllable using MS NT (maybe), W2K, XP but I understand that there is a problem controlling it with Vista. According to Felx Radio there is third party software to control the SDR-1000 with Linux but I'll be darned if I can find anything that gives steps 1, 2, 3, to take, to download, compile the application or configure the radio. If a manufacturer claims that there is 3rd party software but can't tell you where it is, then I think they should not claim that there is such software and let it go at that. For that reason I am leery of buying hardware that makes such claims. I have seen demonstrations of the SDR-1000 and I have used the TS-1000/2000 series radios and the SDR-1000 is most impressive against the Yaesu radios. 73, Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Peter G. Viscarola Sent: Monday, February 12, 2007 1:30 PM To: digitalradio@yahoogroups.com Subject: [digitalradio] Can I get a rig with MORE? I work digital modes (PSK, RTTY, MFSK, Olivia, etc) almost exclusively. I also have a pretty low noise environment, living out in the country and with my antenna (a dipole) almost 100' from the nearest RF noise source. Note that upgrading my antenna system is really not an option at this point for a whole lot of reasons. I presently have a TS-2000 and I like it a lot. I like the ability to use the IF DSP to narrow the passband from each side to isolate the signal I want. I've been pretty successful with it, too. Given my modest setup I'm rapidly closing-in on my first 100 for DXCC, after being on HF for only about 4 months. Could I gain some sensitivity/selectivity/better filtering by upgrading my rig? What rigs might folks suggest? How about the SDR-1000? Better? Worse? Something else? I'm relatively new to HF, so I'm looking for some elmering I suppose -- Is my rig doing as well as any? Or, is a significant step up possible? Again... I'm interested strictly in digital mode performance. And, again, while I'd *like* to put up a tower with a beam (and I *know* the old adage about 1 dollar spent on antennas is worth 100 spent in teh shack), that just can't happen (for any price I can pay) given my location. Thanks for your opinions, de Peter K1PGV __ Announce your digital presence via our DX Cluster telnet://cluster.dynalias.org Our other groups: http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/themixwgroup http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/wnyar http://groups.yahoo.com/group/Omnibus97 Yahoo! Groups Links -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
Re: [digitalradio] Can I get a rig with MORE?
Howdy: The board brush strokes are easy. I do not have enough patience, smarts, or time to do what Bob Cowdery has done in his fantastic erlang implementation. On the other hand it does not fit with my vision of this and so far, Frank agrees with what I have been saying so I am assuming it is substantially his vision as well. The idea is to have the erlang be the simplest possible thing, as few lines as possible to get the job done reliably, robustly, with remoting built in from the word go. Cnodes are big in your future. dttsp's sdr_core (as an example) will start up as a stand alone program and it will maintain its command structure. Now you use the simple cmdr script to send it commands. e_cmdr will be a C program that starts up and attaches itself to the TINY erlang server. After it establishes its presence, it will negotiate what it can provide and what it wants to receive. So long as it is around, the erlang based hub will send all commands of the registered type to it and respond to all data requests of the type registered from e_cmdr by making a request for this data from e_cmdr, etc. The state held in the erlang radiocore will be the absolute minimum needed. If the cnode disappears, the hub will time out on it and drop it and all of its sources and sinks from the list. You might think of the, erlang cnode as working the exact same way Frank did the code in update.c BUT the CTE array will be dynamic and supplied upon initial connection, etc. in the radiocore. It really will be TINY block of code and the smarts will be in the leaves. I have had Cnodes running robustly on all my machines of every type for months. I keep thinking that it is but a day's work to give everyone the e_cmdr as a template for how to make their connection to the hub and even to provide the simplest possible kind of GUI, something like Roger's little push button GUI but interfaced through its own Cnode interface to the hub as a template for how to proceed. Between having FOUR close relatives with life threatening conditions and being constantly on the road for work, I just have not gotten it done. I apologize to everyone. No one is more unhappy about this than me. I need an uninterrupted week at home. This week I am in Boston fighting the snow going to Cell processor class at Mercury and next week I am at VPI working on OFDM with GnuRadio folks for MY WORK. I will catch a breath soon. Bob kd5nwa wrote: I downloaded the code from the SVN a couple of days ago and I'm wondering what will the Radio core will do, I don't need a detailed explanation just some broad strokes. At 05:15 PM 2/15/2007, you wrote: Walt: Frank, Eric, and I have specfically answered all of your questions about the Linux support. It is completely controllable under Linux now especially for those who have no need for fancy radio GUI's. For those that need GUI's there ARE GUI's and more will be coming. Roger Rehr has painted the road with crayola crayon especially for you: http://www.nitehawk.com/w3sz but the Linux code does not have the polished presentation of the Windows version of code AND IT DOES NOT SUFFER FROM ITS LIMITATIONS. It is poised to take off now. There are several approaches to take such as dttsp-shell (available from Edson Pereira) or the java GUI done by John Melton or usSDR gui done by Jonathan Naylor. Frank and I are not interested in doing this GUI work. We are interested in support anyone who wants to do the GUI work. Bob N4HY (coauthor DttSP with AB2KT) -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
[digitalradio] [Fwd: [tapr-announce] HPSDR Janus and Ozy Board Production Announcement]
-- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine ---BeginMessage--- *** TAPR ANNOUNCES PRODUCTION OF HPSDR JANUS OZY BOARDS *** High Performance Software Defined Radio Project (HPSDR) *IMPORTANT* TAPR and HPSDR need your input! Please help us by visiting Dale's (WA8SRA) HAMSDR website (see below) and let us know if you are interested in purchasing Janus and/or Ozy bare or assembled boards for delivery by May. THIS IS NOT PLACING AN ORDER; IT IS AN EXPRESSION OF INTEREST SO THAT WE CAN MORE ACCURATELY DETERMINE HOW MANY BOARDS TO ORDER AND ASSEMBLIES TO MAKE! This opportunity will end on Tuesday, February 20th at 0200 UTC. To register your interest you need to go to the Dale's (WA8SRA) HAMSDR website, in the projects section. If you are a member and have previously expressed interest in these projects, log in and re-enter your quantities of each board. NOTE: Previous quantities have been reset to zero so you WILL HAVE TO RE-ENTER QUANTITIES. If you are new to HPSDR and Dale's Website, please join for instant access by providing the information requested. Go to: http://www.hamsdr.com/HTTP://www.hamsdr.com Login and go to Projects TAPR-HPSDR and click on Indicate Your Interest button to create a new record for entering your quantities. What is HPSDR? http://hpsdr.org/http://hpsdr.org What is an Ozy? http://hpsdr.org/ozy.htmlhttp://hpsdr.org/ozy.html What is a Janus? http://hpsdr.org/janus.htmlhttp://hpsdr.org/janus.html There are many other HPSDR projects in design and testing; most will require the Janus and Ozy boards. ___ tapr-announce mailing list NOTE: This list includes all addresses currently subscribed to any TAPR mailing list. Please don't try to manually unsubscribe from this list; it won't work. If you unsubscribe from all other TAPR mailing lists, you will automatically be unsubscribed from this one. ---End Message---
Re: [digitalradio] Re: SDR-1000
I pushed forward to a new repository (sdr_linux) today. Frank and I did the dsp/sdr code and Eric Wachsman and Flex did just about 100% of the hardware code in support of the SDR-1000. It runs on linux, cygwin on MS and native on MS (using the MSVS 2005 express) and probably OSX. It drives both the parallel port and the USB interface control for the hardware. As a result of Eric's efforts at Flex, we will for the first time be able to control all pieces of the SDR-1000 hardware on Linux, Windows, and probably Mac OSX using the USB interface and libusb. He did this while on the clock at Flex with help from Frank and I on makefiles. Given the myriad consoles by Pereira, Melton, etc., this should result in a working GUI driven functional radio pretty quickly for these platforms independent of Flex. Frank Brickle wrote: --- In digitalradio@yahoogroups.com, Walt DuBose [EMAIL PROTECTED] wrote: I'm not going to spend $1500 for an SDR transceiver I can't run from Linux. Roger's website is the best source for information on getting started. There will be new information forthcoming by the end of the weekend. As of a couple of days ago, sdr-core and sdr-shell are now running under Mac OSX as well. I think it's accurate to say that Flex isn't going to attach any importance to real Linux support unless users demand it and demand it vocally. That's exactly what happened with CW. The importance of decent CW performance was dismissed out of hand until it became clear that the lack of it was costing them sales. Once the point was made, the CW performance was improved beyond recognition to its present high standard. We agree completely on CW since I still have the note where Gerald asked us who was complaining about CW? and disagree on Linux and Flex because Gerald is completely aware that the embedded micro in his new gold plated radio cannot run Vista for myriad reasons and has said this explicitly to Frank and I.In a multiway exchange, Gerald said explicitly that Linux would be first out of the gate on any new radio with an embedded micro for dsp/sdr in it. Time will tell. 73 Frank AB2KT 73's Bob N4HY P.S. Frank and I are not employed by or paid by Flex. -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
Re: [digitalradio] ALE CQ and ALE GPRS Re: SDRs Open Possibility for 18kHz Bandwidth HF Data?
Howdy: And open source on all parts of our (Frank and I) work should make this attractive to someone to do, not necessarily us. We have been constantly amazed at the talent which comes out of th woodwork and talkes up what has been done and makes it better or uses it in someway we had not envisioned. This will happen with this as well. I am really happy the League is considering this. We will all benefit from it and this is very forward looking on their part in my opinion. Bob Frank Brickle wrote: --- In digitalradio@yahoogroups.com, expeditionradio [EMAIL PROTECTED] wrote: We also have adapted ALE to do APRS-like stuff. But we call it ALE-GPR. The ALE protocol, especially with what you can do with AMD, is flexible. And in any case none of this is the last word, especially when hams start chewing on it. For example, last year I did some statistical measurements on typical NMEA sentences which indicated they're seriously redundant, about 75%. Source coding could allow tucking the full vocabulary of GPS messages in all sorts of odd places in the protocol. No reason to be limited by even what's been improved so far. 73 Frank AB2KT -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest. - Piet Hine
Re: [digitalradio] Re: Movement toward open digital software?
Exactly. My personal experience, which I believe is nearly identical to Frank's, is found in our doing the software defined radio code (which is used now by thousands of radio amateurs and others) finds Simon's fear is misplaced. However, it is a personal (if incorrect ;-) ) decision and his to make. That does not keep us from voting with out fingers and feet and going elsewhere. If Simon's game is the only one in town, then we are left with no choice. DttSP, Flex Radio, GnuRadio, HPSDR, uwSDR, AEA DSP1232/2232 all run code that Frank and/or I have written (along with many others). My experience with open source in these projects is that it has been utterly glorious and the few Neaderthal's that come dragging their knuckles out of their caves are a minor annoyance. We have been aided greatly and have learned a tremendous amount from doing business this way. Soapbox shoved firmly back in to the closet, Bob N4HY Frank Brickle wrote: --- In digitalradio@yahoogroups.com, Simon Brown [EMAIL PROTECTED] wrote: Spot on. I use a commercial library from Codejock - www.codejock.com - this cannot be distributed. I also use other commercial libraries with similar restrictions. I can only ship the runtime libraries or link the code into my executable. You don't have to distribute their libraries to open your source, unless their API is covered by an NDA. As far as questions about myriad versions go, Let us all know when you find out! is as good an answer as any. 73 Frank AB2KT Announce your digital presence via our DX Cluster telnet://cluster.dynalias.org Our other groups: http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/themixwgroup http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/wnyar http://groups.yahoo.com/group/Omnibus97 Yahoo! Groups Links -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you board the wrong train, it is no use running along the corridor in the other direction. - Dietrich Bonhoeffer
Re: [digitalradio] 10 Khz signal
Is it heard at night? Then I am going to guess that it is digital radio mondial broadcast. Bob N4HY Chuck Mayfield - AA5J wrote: What is the signal that occupies 3990 to 4000? -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you board the wrong train, it is no use running along the corridor in the other direction. - Dietrich Bonhoffer
Re: [digitalradio] Re: OFDM data is Emission Designator D1D
Thank you for the note. If it is designed the way you say (and this is not contraindicated by the document I provided a link to) then the bauds in the detector will be orthogonal. 73's Bob N4HY cesco12342000 wrote: relevant to its classification to OFDM. Which it is NOT. The carriers are on 120 Hz centers and the baud times are 100 Hz. Because the baud time is not commensurate with angular frequency of the carriers, the dot products are not zero and therefore, they are NOT orthogonal in PACTOR-III. I do not agree. 100 baud means 10ms/symbol, of which 8.33ms symbol time, 1.66ms guard interval. Carrier spacing is 1000ms/8.33ms = 120hz. The carrier spacing is orthogonal to the integration time, and not to integration time + guard intervall. It's exacly like all the other ofdm systems. Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Yahoo! Groups Links -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair If you board the wrong train, it is no use running along the corridor in the other direction. - Dietrich Bonhoffer
Re: [digitalradio] Omnibus rules published in Federal Register
Dan: Why would the ARRL do this? It is my opinion that coupled with the parts of Pactor-III that are considered trade secrets, Pactor-III is in violation of Part 97 making it an encryption. There is no provision in part 97 for being able to receive it with ridiculously priced hardware, it simply MUST be a completely reproducible specification available for open reading to not be in violation of Part 97. The League does not help the situation by aiding SCS continue to be a scofflaw. Bob N4HY Theodore A. Antanaitis wrote: Received this reply today: Hi Ted: As of Dec 15 Pactor-III running at a bandwidth of greater than 500 Hz (such as Winlink) is not permissible below 30 MHz. This is one of the petition to reconsider items being considered by the ARRL Board of Directors. Thanks and 73 Dan Henderson, N1ND ARRL Regulatory Information Specialist -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein
Re: [digitalradio] What is an image and what is data
These FCC rules are very poorly drawn. I can send every signal digital file transfer in the phone band with a single bit per second of an image as that makes it an image transfer. I do this by attaching an icon/avatar to each transmission. I then get 3 kHz to do my file transfers. To avoid this, we would need rules about what percentage content identifies the type. This is just the worst kind of a) engineering, b) policy, and c) lawyering done at the F.C.C. in concert with several years of misguided efforts from our representatives.If there are to be restrictions about what goes where, I think bandwidth is the only restriction that makes any kind of sense. I am generally opposed to this as a matter of principle because it severely limits innovation. The degradation of technical talent at the F.C.C. is really bad. Let me give an anecdote. Once there was a meeting there on matters covered in the omnibus bill (read my sig, first part and you can probably guess what would impact me). We were subjected to some amount of bullying and arm twisting which was resisted with a stony demeanor. We later did the proper set of responses which would allow us to enter federal court to battle the regulations. In these meetings, there was a public admission of pride that there was a fellow ham in the room and that he was an engineer. He was the only engineer in the room for them and was clearly junior. At the end of the meeting, as our group was heading out, the engineer walked with the group, said how glad he was we came, and he apologized for the chair's demeanor and mistake. Mistake? He said he was not an engineer but was a lawyer who happened to be an amateur radio operator. Since he had all of this practical knowledge from his hobby, he was often perceived to be an engineer. It was one of the saddest moments I can recall in dealing with these kinds of matters. The F.C.C. is a clear iconic symbol for Absolute power corrupts absolutely and Money is the root of all evil. The billions at stake in their rulings has forced any kind of technical talent to be submerged beneath a tidal wave of politics and lawyers. Bob N4HY Mark Miller wrote: The answers to these questions about what is an image is simple in one respect. The current FCC rules allow digital emissions throughout the 160 through 10 meter bands. This is true because emissions that have a 1 or a 2 as the second symbol of the emissions designator are allowed everywhere. It is the content of the digital emissions that is segregated, and this is the third symbol. So if the content of you message is data, then the emission that you are using had a D as the third symbol. If the content of your emission is an image then the third symbol is a C. If the content of your message is telegraphy for automatic reception, then the third symbol is a B. What is telegraphy? Telegraphy in this case is defined in part 2 as: a form of telecommunication for the transmission of written matter by the use of a signal code. Facsimle is also a form of telegraphy, but is for the transmission of images. What is complex is capturing an emission and determining if it is an image or data. Win DRM is a good example. You can send F1D and F1C with WinDRM, but unless you decode it, you cannot tell from the emission whether it is an image or data. 73, Mark N5RFX -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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: BPL-Busting Modes/Techniques
jgorman01 wrote: I'll try to keep this short. First, the review I quoted was the first one the ARRL, I went back and read the second one. Some comments: I agree the numbers that came out of the test are impressive. --- snip --- Now a little of my engineering scepticism. --- snip --- I understand your promotion of your products. But again, if I understand what your promoting, forgive me if I have doubts that an $85,000 system is comparable to what you say may cost less than $300. In my soon to be 56 years on this earth, I have learned that you get what you pay for and seldom, if ever, get a deal like this. If you can offer one at that price, again, congratulation, you are going to be the next Bill Gates! The entire purpose for HPSDR is to do this experimentation for the good of us all. We have come together to provide these capabilities in inexpensive systems for the amateur radio and SDR experimenter. I can only assume that Ulrich Rohde (Rohde and Schwarz, he of the many tens of thousands of dollar toys) tells us he is so interested in this work because it is so interesting. He is a regular contributor to HPSDR concerning LO's, Mixers, etc. and is absolutely looking at the technology to mine it for the XK-5000. THis is understood by every contributor. There are many big company manufacturers there listening, lurking, consuming. We are having exactly the impact we wanted to have and money has not been a motivational factor. I hope it never is. The pay for what you get comment is probably appropriate. You will not be given a life time warranty and pay tens of thousands of dollar supporting large corporate offices and stock holders who do not provide any service to you at all but you will also get no on-site support or after market hand holding. For some applications, the cost of these things is worth every dime because the end user must be supported. In our case, we are aimed at increasing knowledge and providing tools for the modern day homebrewer in the best traditions of amateur radio. We are in the chasm between the old way of doing amateur radio and whatever excitement the future may bring. We have done little beyond changing out tubes for transistors and added in a little DSP shaping. SDR with all that means, is our way into the future, since it is programmable to meet the demand. By the way, Ulrich Rohde is not the only super star member of HPSDR. There are several serious industry players who are lurkers. You might also be up front and tell the folks on an HF Digital forum, that as of the last ARRL review the turn around times of your system makes it usable for ARQ modes at the least. Like 170 ms versus 24 ms for the Icom ProIII. Likewise that the group delay of the software filters requires reducing the number of taps from around 2000 to 200+, thereby reducing their effectivness for digital communications. You might mentionthe ARRL tests showed the SSB carrier suppression and opposite SSB suppression on TX is only 53 dB vs the ProIII's at 70 dB. Again, over my lifetime, I have learned that not everything comes up roses. Products require compromises and you need to be up front with the pimples. Isn't it great that we are doing a software defined radio? I love what Willi Rempel said. Each new day and each new software release is like a brand new radio. That may be an exaggeration but in this case, that is not far off. The radio switching times was entirely a software issue AND IS COMPLETELY RESOLVED.I am not happy with all parts of it, but a couple of months of software investigation, badda-bing badda-boom, and you have personally walked into my spider's lair and given me THE PERFECT opportunity to make my point. The radio switches in 5 ms from receive to transmit and transmit to receive and in this case, ON CW and digital modes, with a single release of software, it is like a brand new radio. Lastly, you said ...it is frustrating to me personally that what is happening right under amateur radio's nose is so badly misunderstood and insufficiently appreciate. I believe as strongly as I believe I am typing this note that most of you have purchased your last conventional HF transceiver because of this work. What vehicle should I use to scream these roof tops so educated interested people like Jim can understand how much things are changing? I do understand how things are changing, but I also understand how they are not changing. A little background. I am a BSEE, and when I started work at Southwestern Bell Tele. (now ATT) I was like you and couldn't believe how backward folks were. How computers should be changing the world RIGHT NOW. However, I learned there were budgets, for hardware, software, and most importantly, hiring and training people. These budgets were limited and controlled how fast things changed. I do not believe people are backwards. I
Re: [digitalradio] Re: BPL-Busting Modes/Techniques
jgorman01 wrote: S-meters are not just logarithmic indicators, they also indicate the gain reduction being applied in the RF/IF chain. As I said in a previous post, it is an indicator of the reduction in gain, i.e. how much of an attenuator is being inserted. By inserting this attenuator you are not just inserting an S5 level of reduction, but an S9+10 dB level of attenuation. Therefore the smaller signal is reduced by a much larger amount than its absolute level would need. This means it doesn't come out of the audio amp at an S5 level but at something much less. SDR's still have to deal with the real analog world at some point. RF preamps and amplifiers that have a large dynamic range are not easy to design and build. That is why AGC is applied to them, to limit the range they have to handle. As an experiment turn off your AGC and see what level of signal it takes to overload at least some of the stages in your receiver. I can HEAR audible distortion on S9 signals. This means signals much less than this also have distortion. Now this may not be occuring in the first RF stages but it likely could be. This is wrong. The SDR-1000 has a measured IMD-DR over 100 dB, with an IP3 north of 30 dBm. It does not have a single analog amplifier with agc on it. All agc is done strictly in software. Great use is made of the fact that 200 kHz wide I/Q if's may be captured using modern audio codecs that exhibit 99 dB of dynamic range themselves (or more) and then we proceed to filter and downsample and get increased range by doing that. This of course limits the blocking dynamic range to about 100 dB as well. This will increase as a DIRECT result of getting and using better codecs. This is happening now in support of the SDR-1000 by HPSDR. SDR's may very well be an answer to cheaper high performance receivers, but so far the measurements I have seen don't show a dramatic improvement, for example, even half again the dynamic range of current decent analog receivers. See the ARRL review on the SDR1000. I am sure better performance will come, but at what price is a question. Here is a reference I found about a high performance system. The SDR-1000, with which I am intimately familiar (having jointly written all of the DSP software in it with AB2KT) was a stack of boards layed out with a free tool. The stack of boards are 3x4 inches because that is what Eagle would do for FREE. It is a beyond lucky happenstance that with small component modifications the thing is able to get the numbers mentioned in the ARRL review. I suggest that you have misread it if you do not understand what a complete REVOLUTION the SDR-1000 is. The high dynamic range and the IP3 measured in the ARRL review ARE AT 2 KHZ! Not 20 kHz, not 5 kHz but 2 kHz. And the only reason the measurements are not done closer than that is the ARRL laboratory is incapable of have a sufficiently noise free generator to measure that close. The ARRL review you quote states (AFTER the review for the Orion and IC-7800 came out) that is was about the best receiver ever measured in the ARRL labs. MAJOR technical innovations have been made inside and outside of Flex Radio on the theory and implementation of the what Gerald calls the QSD and what others call the Tayloe detector. I understand its principles of operation completely having completed a detailed transform analysis and have suggested how to greatly improve the circuit. These considerations are being applied by Gerald in his new receiver design and they are being applied by HPSDR in a separate design based on low noise amplifiers I chose and a codec I recommended and an approach that started with Phil Covington, N8VB and spurred my technical analysis after Tayloe said that the essential nature of the beast was an integrator and not an RC network. I do believe people will be shocked at how unbelievably capable these inexpensive receiver components will be. For Flex Radio, they will be applied in expensive radio systems under design for the high end user. In HPSDR, they will be applied in modules clearly aimed at the experiment. We have, absolutely no doubt in my mind, the CORRECT tools to do amazing digital work for HF and reasonably inexpensively should we choose or very expensively if we choose to have a major new rig. The Model 7640's FPGA serves as its control and status engine, and is supported by 512MB of DDR SDRAM for buffering functions, such as data capture and delay. The transceiver digitizes HF (high frequency) or IF (intermediate frequency) input signals using a pair of 14-bit, 105 MHz A/D converters, and generates output signals with two 16-bit, 500 MHz D/A converters. See it at http://www.linuxdevices.com/news/NS3911104852.html It only retails for $85,000! The HPSDR Mercury and Ozy boards are 135 MHz 16 bit A/D with 90 dB range (I measured the A/D) and two Cyclone II
Re: [digitalradio] Re: BPL-Busting Modes/Techniques
list email filter wrote: not_so_tongue_in_cheek If I am 800 miles away, outside the local disaster and power outage area, and could have provided assistance, but can't hear you through my local BPL QRM, or have given up HF communications all together as the newly required digital BPL busting technologies are too expensive to play with, don't we all lose? /not_so_tongue_in_cheek I feel that it is the responsibility of the software defined radio groups to go forward and provide for these capabilities since it really is the only way. I will not defend this in detail here but I believe it strongly for all sorts of theoretical and practical reasons. 73 Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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: BPL-Busting Modes/Techniques
jgorman01 wrote: I may be wrong but I beleive your theory doesn't assume that the RF energy at your reciever's antenna is not additive. In other words, the signal from the transmitter you want to hear and the interfering signal do not add together. You can only discern the strongest signal. An example is, that if you put a carrier on the air and I receive it at S9 and then someone else puts a carrier on the exact same frequency but it only arrives at S8, I'll never know it is there. The only kind of receiver that does this by design is one in which a limiter is in the front end (or other undesireable nonlinearity) and exhibits the capture effect (such as FM receivers). So you statement is false. They do add to the extent that the front end and following stages continue to operate linearly. If BPL is very close to you, and the other signal is weak, then it is possible (easy) for the audio difference coming from a typical amateur radio transceiver to exceed the dynamic range OF THE AUDIO CIRCUITS (not the front end or the IF's). For some of the SDR transceivers, where the audio dynamic range is presented digitally to the processing programs (the audio never leaves through a D/A or speaker or wire of any type) through a virtual audio hookup (done with software wires rather than hardware wires). I feel this is one of the major assets of these SDR approaches (SDR-1000, GnuRadio, HPSDR). The other major asset of each of these SDR systems is that they can, or soon will be able to, tune a signal that is almost 200 kHz wide. Therefore, when you remove the interfering signal, you also remove any possibility of retreiving information from the signal you want to hear. Consequently, you will never have a coherent signal to decode. It will always have missing information. There is information degradation but your nonlinearity reason is incorrect insofar as it went. Any other assumption means noise, especially random noise, would not be a problem, and that you could always subtract a signal from it. Every mode I know of, digital or analog, has a minimum signal to noise ratio that is required to decode it. This is correct. BPL is not very noise like in comparison to a very well designed digital system where randomization of the data, forward error correction, source coding (compression) all make the data look flat random. So a system to defeat BPL must be designed to overcome the nonrandom statistics of the BPL excitation. There will be a signal / (noise+interference) ratio beneath which we cannot go further. This is well understood what it is even if it is difficult to compute (with interference being decidely nongaussian and the channel having memory). If you demand 1000 bps from the channel and the capacity is 999 bps, you have exceeded the capacity and information will be lost. Any system that will communicate through BPL interference must degrade gracefully as the channel information capacity decreases. It is the demand for fixed rate where that rate exceeds capacity that leads to a graceless collapse in our HF systems. One of the things the illegal encrypted communications Pactor III does, is decrease the information rate to be below the capacity (any digital system where the complete specifications allowing duplication are not published is a violation of Part 97) to allow for continued communications at the reduced rate. There is no one size fits all with these horrid HF channels. Any system designed to replace what we have will ultimately have to accept this and build for it. Jim WA0LYK Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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] Armstrong 'got Moon quote right'
Bill Turner wrote: ORIGINAL MESSAGE: On Mon, 2 Oct 2006 18:52:42 -0400, Andrew O'Brien [EMAIL PROTECTED] wrote: Armstrong 'got Moon quote right' REPLY FOLLOWS Boys and girls, you have just seen a prime example of historical revisionism. Usually it's done with more subtlety, but technology has allowed a more in-your=face approach. After all, who can argue with technology? :-) Bill, W6WRT who is sure this has something to do with digital radio This is more analogous to DNA testing revolutionizing forensics and reversing some (wrong) convictions. A newer technique embodied in an easy to obtain audio processing software package was applied and it basically showed the tail of the impulse response of the comm system to the a. His vox dropped out at just the wrong moment, but you could see the signs of the a having been uttered according to this analysis. It is persuasive and for the sake of one brave men and a great hero , I choose to believe it. Bob -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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] Concerning Signal Detection
DuBose Walt Civ AETC CONS/LGCA wrote: My uncle, Charles Sumner Williams (author of Introduction to the Optical Transfer Function), who taught radio at Scott Field during WWII and retired from TI said that the problem with computer signal detection (we were discussing CW) was trying to duplicate with a computer what the human brain could do was difficult. However, once you succeeds, the computer is likely to be able to do the job better. I did not realize until much later, that in part he was talking about how our brain, perhaps acting as a quantum like computer, takes current and past information to predict the future and that the brain can be trained to reject certain sounds, patterns and the like. I believe this is correct. You cannot do this job correctly and only treat it as a conventional signal processing problem. FEC works on digital signals by building in redundancy. Better decoding of CW would make use of the existing redundancy rather than just is it on or off?. CW sending words clearly has significant Markovity in the actual transmitted tones. To not take advantage of the predictability of the next character or element given those elements just preceding it would be folly. In the case of distorted signal or signal in noise or interference, this is a Hidden Markov process. The algorithms for treating this under certain assumptions are well known and understood. iNTUITIVELY, one looks at the possible outcomes for the next element and picks the best outcome given the observations. One should use signal before AND after current element under consideration as the observations. The brain certainly uses this. I struggled like mad when I was attempting to learn to copy faster morse before I got my extra in the early 1970's. My speed really took off when I relaxed, allowed myself to fall a little bit behind. Now it is clear I am using signal information before and after the object I am attempting to decode. Then the speed really went up when I started copying words and phrases and not letters. Mathematics remains the fundamental science used to analyze and explain the complex algorithms of human speech. Virtually every branch of pure and applied mathematics has proved to be useful in these efforts. Where the human brain is a biological computer, the computers humans build simply tries to emulate this function...the human brain is our basis and model. Understanding this concept will greatly enhance our ability to create a better HF modem. Walt/K5YFW The mathematics of this kind of language modeling applied to signal processing is simply fascinating. 73's Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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] BPL-Busting Modes/Techniques
expeditionradio wrote: BPL-Busting Modes/Techniques --- snip The development of new amateur modes, semi-automated and automated frequency agile systems, advanced ARQ, and various sorts of FEC digital techniques are a possible avenue for amateurs to communicate through the interference caused by BPL. It may not be possible to entirely eliminate all the harmful interference BPL creates, but we need to start planning for mitigation. We need to research and characterize the various types of BPL signals so that we can design modulation and control techniques to compensate for them. I recently had a general manager of a large amateur radio organization tell me that if I made it possible to communicate through BPL or in any way mitigated BPL through DSP techniques, I would begin to sing soprano and the GM did not mean falsetto. Using radio engineering and specially-designed digital signal processing, we can develop BPL-Busting Modes. These new modes and systems could carry any combination of voice/image/text/data. Frequency hopping, spread spectrum, wideband OFDM, multi-PSK, ALE, and MFSK are mode/systems that we could implement immediately in new formats... Unfortunately, hams in USA don't have the freedom within the USA FCC rules to advance some of these yet. We look to hams in other countries to pioneer these new techniques. Any technique that would allow higher rates and near bullet proof performance would necessarily sound a whole lot like noise and would necessarily be fairly wideband and would not work in today's traditional radios but would certainly work in the SDR radios. I am afraid that if I didn't have the general manager alter my singing pitch, the rest of ham radio might. Under USA FCC current Amateur Radio Service rules, we do not have the freedom that other countries have, to take advantage of some of the most useful technologies that could help us to communicate through BPL interference. We are still locked in our technology prison. Hopefully, in the near future, we will have more freedom... with bandwidth-based spectrum management. I say that we can do turbo trellis coded based OFDM that are designed for fading dispersive channels with cochannel interference. One of these years when I have yet another life to give, I am certain I can do it and pound tons of data through. The research in ARQ and the development of ALE should indeed allow us to greatly improve the robustness of our link to effectively use the fancier modulations. 73 Bonnie KQ6XA Thank you for starting an interesting thread. 73 Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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: What is this noise?
I agree with this. The switchers typically have a free running oscillator in them so they drift and coupled with insufficient RFI prevention. This gets coupled into a receiver where you can be running as much as 100 dB of amplification in the entire receiver chain. Bob N4HY expeditionradio wrote: Switching power supply. 73---Bonnie KQ6XA --- In digitalradio@yahoogroups.com, Andrew J. O'Brien [EMAIL PROTECTED] wrote: I have noticed an occasional noise generated by my receiver, seems -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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] 188-110B Adaptive Equalization
Mark Miller wrote: Steve, Is there adaptive equalization used in the PCALE or MARSALE implementation of 188-110A or B? 73, Mark N5RFX We do not have the source code but from the performance anecdotal evidence given us by Bonnie and others (transmitting the images) it would not work this well without the Adaptive Eq. This is needed, absolutely mandatory, to mitigate the fading multipath HF channel. Bob N4HY -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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] 188-110B Adaptive Equalization
188-141 does not merit adaptive equalization in my opinion. At 125 tones per second, one of 8 tones is turned on. Each tone sends 3 bits as a result. The data is encoded with a Golay code. This is about twice as fast as is optimal for most HF channels given this kind of transmission (IMO) but the Golay really does work. Bob N4HY Mark Miller wrote: This is needed, absolutely mandatory, to mitigate the fading multipath HF channel. Bob, Thanks. I have not had a opportunity to send images with 188-110, but after reading the specification, I thought adaptive equalization would be necessary. I look forward to sending images. I have been hanging out of the 20 meter channels hopping that conditions would be right to do some testing. So far I have only used the messaging in 188-141 which I don't believe has the training sequence necessary for adaptive equalization. 73, Mark N5RFX 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 -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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: ALE QRM is minimal
What? That was basically unintelligible. Mil Std 188-110-A1 2400 baud serial modem combines several features to mitigate the channel. Furthermore TWENTY FOUR HUNDRED BAUD DOES NOT MEAN 2400 bps. It almost never does. What happens in the modem is multiple 2400 baud symbols are put together to encode the data at a slower rate. This can be as low as 75 bps.The channel symbols are sent at 2400 baud. There is forward error correction done on the data and the encoded data is permuted in time in a block form. The type of forward error correction works best when the channel induces errors in isolation. On a typical HF channel, the errors come in bunches. So the permutation mentioned above, spreads these errors out in time to isolate them. CLEVER DEVILS. This was the ingenuous trick that made it all work. To slow down the data rate, the data is repeated from zero to several times. The encoded redundant data provides more energy per bit since it involves now N more bauds (where N is the number of repeats). I have NEVER in many years of working with this scheme, seen the high DATA rates work well over multiple hop channels. I have seen 1200 bps be quite robust and 600 bps very robust indeed. I have seen 75 bps work when you cannot detect the modem is on the channel. 73's Bob N4HY DuBose Walt Civ AETC CONS/LGCA wrote: The 2400 and 4800 baud is a composite baud rate for the mode/protocol NOT the discrete baud rate of any individual component of the waveform. Walt/K5YFW -Original Message- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Friday, September 01, 2006 11:07 AM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Re: ALE QRM is minimal Can you explain how it is that you can run a symbol rate of 2400 (baud) with 188-110A and it works very well running at this extremely high speed for HF? And yet other modes, such as Packet, don't work very well at 300 baud, and Walt has pointed out that government studies had show that under 50 baud was about the optimum for the types of conditions we often find on HF? Why would we not just increase the baud rate of MT-63 or MFSK16 to get a similar speed boost if it can work that well? How tight do you need the frequency tolerance to be to enhance weak signal modes? The ICOM Pro rigs run at around 0.5 ppm, which seems several orders of magnitude better than what some of the digital mode programs require. I wonder how much better a weak signal/difficult condition mode we could come up with if there was a tighter frequency tolerance. You might recall the early developement of Clover I, by Ray, W7GHM. If I remember right, the signal was phaselocked to WWV or other time standard frequency. Later this was abandoned with DSP developed as a bus card and the computer mostly being used as a dumb terminal, but it will never be as tight a frequency tolerance as 10 e -6 or so:) 73, Rick, KV9U -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat. - Einstein 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: Insulting Subject - Exalted Mystical Busy Channel Detectors
Dave: The technical specification is incomplete. You may not take their documents and implement a compatible system (been there, done that, got the tire tracks on my back). They have not made these specifications public to my knowledge anywhere, including the F.C.C. As such, I do not see why it is not an illegal scrambler in the U.S. Bob N4HY Dave Bernstein wrote: I don't think the problem lies with SCS, Doc. First, they have provided descriptions of the Pactor 2 and Pactor 3 protocols; the absence of alternate implementations is more likely the rsult of constraints imposed by Windows than technical obfuscation by SCS. Second, Pactor 2 and Pactor 3 in keyboard-to-keyboard mode are, from a QRM-generating perspective, no different than RTTY or AMTOR -- there are operators on both ends listening to the frequency, so QRMing an ongoing QSO is unlikely. The problem is semi-automatic operation without busy frequency detection. This results in QRM to ongoing QSOs, and there's no way to communicate with the station generating the QRM even if you happen to have the right modem because the guilty station is automaticly controlled! This is the case with semi-automatic operation in CW, RTTY, or PSK -- the fact that Pactor 2 or Pactor 3 are being used by many message passing services (because they are fast and error-free) is actually irrelevant. Enforcement would certainly be easier if we could eliminate the need to decode every protocol out there. Requiring the participants of each digital mode QSO -- whether attended, semi-automatic, or automatic -- to periodically identify in a common, easily-decoded modulation and format would greatly facilitate self-policing. 73, Dave, AA6YQ -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman Laziness is the number one inspiration for ingenuity. Guilty as charged! Yahoo! Groups Sponsor ~-- Check out the new improvements in Yahoo! Groups email. http://us.click.yahoo.com/6pRQfA/fOaOAA/yQLSAA/ELTolB/TM ~- 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: Dominoex/SDR1000
You do not need a second sound card. You need the pseudo sound card. Virtual Audio Cable, version 3.12 only. http://www.flex-radio.com/download_files/PowerSDR/Docs/PowerSDR_VAC.pdf http://spider.nrcde.ru/music/software/eng/vac.html DO NOT ORDER 4.01. ORDER ONLY 3.12 I have just added the thermistor which will soon be offered to stabilize the VFO and it is like a rock. Newer radio's have it and the one you got from WS might already have it. 73's Bob N4HY KENNETH MICHAELSON wrote: Thanks for replying, Andrew...Yes, a second card is supplied with the kit, a Delta-44, at an additional cost of £99.95. And that incidentally, in my ignorance, is most of what the trouble is..You are supplied with a 'Breakout Box', and the variations of types of output and input from this card are srnding me round the bend. Andrew, I can't cope with it as it is...Again thanks for the reply...73 de Ken G3RDG -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman Laziness is the number one inspiration for ingenuity. Guilty as charged! 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 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.
Re: [digitalradio] Re: How Safe is Amateur Radio
Soapbox entry: I don't believe we are in any serious current danger of frequency swiping on HF but I do believe we are in a demographic crunch. There will begin to be massive die off of hams (statistically speaking) in about 10 years as we continue to age nearly one year per year as a population. At that time, the amateur radio market will probably collapse since there will be insufficient commerce in this market to sustain it in any serious way. When government and commercial entities perceive this as being imminent, I believe at that time we will be most vulnerable and frankly we should be. Not one credible thing has been done to address the lack of interest in amateur radio by those that are younger than 30 years old. The frequency swiping at UHF+ is about to commence. Let me give one example. IF the Europeans get Galileo, a system no one needs, and it gets health, safety, etc. consideration in Europe, the 23cm is one we can kiss good bye. That is clearly the most popular microwave band. 802.22 is the first of the cognitively defined radios to do dynamic spectrum allocation for commercial purposes and Carl Stevenson has done a very good job of leading that effort. Once the efficacy of that approach is demonstrated on UHF television channels, how can we possibly defend the vast empty wastelands up there? We are under threat, but while it does not seem imminent, once should not duck ones head in the sand and hope it goes away either. Soapbox departure, Bob N4HY Dave Bernstein wrote: With all due respect, Walt, the approach you are taking could be used by anyone to justify anything. During my trip to DC last week, I heard several high-ranking governmental officials saying that unless semi-automatic operation without busy detectors is confined to sub-bands, they'll annex the entire 20m amateur band as a QRM- free zone exclusively for emergency communications. Convincing? Of course not. 73, Dave, AA6YQ --- In digitalradio@yahoogroups.com, DuBose Walt Civ AETC CONS/LGCA [EMAIL PROTECTED] wrote: I wish I could say that we aren't in any danger of loosing amateur radio frequencies...but I am afraid the truth is that even 650,000 amateur radio -- Laziness is the number one inspiration for ingenuity. Guilty as charged! Yahoo! Groups Sponsor ~-- Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/ELTolB/TM ~- Need a Digital mode QSO? Connect to telnet://208.15.25.196/ Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ Looking for digital mode software? Check the quick commerical free link below http://www.obriensweb.com/digimodes.html 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] Anyone using ASIO4ALL?
No, No, and No. KE5DTO and I implemented the use of ASIO4ALL for the SDR-1000. It was and is a stopgap measure. It is only usable if your sound card program can make use of 1) ASIO as the interface instead of MME or DirectX. If you don't know what any of these are, then you definitely don't want it. 2) 24 bit support 3) lower latency. The lower latency can and probably should enable real software nicely timed TOR code to be written. Bob N4HY Paul wrote: In a review of SDR-1000 there was mention of ASIO4ALL freeware. It sounded like its job was faster audio streaming, which implied better audio performance. Has anyone used ASIO4ALL software and found it improved their PSK or other digital modes? If you used it on Win98SE, where did you get the required driver? Thanks and 73, Paul, K7NHB PS: You can look this up at http://www.asio4all.com/ The article that mention it was an old QST review of SDR-1000 The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ Yahoo! Groups Links The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ 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: Visual BASIC [was: Win Link]
There is almost no one I respect more than David Bernstein as a programmer but Microsoft has said it is definitely going to blow off all those developers and tell everyone VB is dead. As such, it will be. I do not believe there will be VB in VS 2005.net. C# and even C++ are forms programmable and I think Microsoft believes that VB had lost its place. They are pretty much sharpening the coffin nails having publicly announced the end of VB. Bob rrlanders2 wrote: Having worked 25+ years in Fortune 500 companies here in the St. Louis area, VB is heavily used. VBA in Access and Excel even more so. VB.NET is following in VB6's footsteps. Like it or not, for business purposes, quite often it's good enough... I didn't make the rules, just get paid to write VB and VB.NET. And yes, you can actually write good code in VB.NET...although it's harder in VB6 73, Rod WI0T The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ 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: Winlink
A transmits to B. C is on frequency and cannot be heard by A and A cannot hear C and transmits. Since B cannot receive A because interference from C, the throughput is destroyed. What you are proposing is an Aloha protocol and with its well known inadequacies. ALE is often misunderstood to be there to allow any typist to use HF equipment to transmit data/messages. It is that but it also mitigates the Aloha/Collision problem since BOTH ends sound the link If A is being interfered with by C at the station B, B will not accept a connection from A on that frequency but will go to another frequency in the pool. http://en.wikipedia.org/wiki/Aloha_protocol http://www.laynetworks.com/ALOHA%20PROTOCOL.htm http://www.mldesigner.com/ApplicationNotes/ALOHA%20Protocol.pdf http://murray.newcastle.edu.au/users/staff/jkhan/ALOHA.pdf Bob Steve Waterman, k4cjx wrote: Please explain hidden transmit effect with an example. Please explain how it is impossible for this also to occur with control operator presence. Steve, k4cjx --- In digitalradio@yahoogroups.com, Dave Bernstein [EMAIL PROTECTED] wrote: I frequently make QSOs on contest weekends, and I am not a contester. Are there some contesters who call over in-progress QSOs? Yes. Does that make it ok for Winlink on Pactor to QRM in-progress QSOs? Absolutely not. Please explain how band planning by bandwidth will mitigate QRM caused by Winlink on Pactor due to the hidden transmitter effect. 73, Dave, AA6YQ The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ 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: Winlink
Steve: It is true that it is a much easier job to say a channel is busy, even with very good false alarm probabilities, than to communicate on that channel. But no one with any sense would try to solve the hidden transmitter problem with a one side sensor. ALE solves this issue by both sides agreeing that the channel is clear enough for use. Then and only then is the Aloha problem really fixed with adequate probability of success. I really do think it makes sense to have links established with some serious two sided three way hand shake protocols. That alone would stop most QRM and ALE style sounding of the channel will allow both stations to grade the current link condition. We do not have to do, nor do we need, full ALE probably but something like it seems very appropriate for this endeavor. Bob N4HY Steve Waterman, k4cjx wrote: Dave, The hidden transmitter issue is solved with signal detection unlike contesting, it has a solution. Your earlier statement regarding the ability of the signal detection in the SCS modem has some disagreement. You stated that the SCS modem only looks for Pactor signals: If you want to disagree, be my guest, but please read the note from Hans-Peter Helfert, the inventor of Pactor 1, II and III regarding the signal detection used in his SCS modems. Not have been involved in writing the code, I will watch the discussion with interest. My posts seem to be getting repetitive replies, and are getting tiring. I am going to give this a rest for a while. I have your points of view. Thanks for your comments. Steve, k4cjx The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ 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/
