Re: [digitalradio] Re: Performance of modes: weak sign al and poor ionospheric conditions
What I don't understand is why NOBODY uses the pskmail arq chat mode, which adds an ARQ layer to modes like PSK250R, THOR22 or MFSK32. Why accept 5% error when you can have it 100% error free? Are you afraid your typing errors get to the other end undamaged? Rein PA0R MFSK16 always seems to come up near or at the top of the simulated tests but I can't duplicate that in the real world. My experience is that Olivia 8/500 does as well if not better and gives MUCH greater latitude in tuning while still providing 100% copy under moderate to poor conditions. Olivia 16/500 is much slower but goes way into the noise where I've had terrible results with MFSK16 under the same conditions. And if 8/250 Olivia (slower yet) doesn't do it, I just turn off the HF rig. BTW, my experience is almost all on 80m with NVIS antennae. -Dave, KB3FXI --- In digitalradio@yahoogroups.com, Wes Cosand wes.cos...@... wrote: I have finished a series of simulations looking at the performance of several modes that seemed appropriate for extended keyboard to keyboard rag chew QSOs. I was looking at modes that offered a throughput of about 40 wpm so they could keep up with a reasonable typist with a bandwidth of no more than 500 hz. I used PathSim to measure accuracy of text transmission under white noise and CCIR 520-2 Poor simulated propagation conditions. I measured text accuracy over at least seven minutes of text for each data point. The graph can be found at http://mysite.verizon.net/wz7i/modeimages/Digital%20Modes%20Poor%20Condx.png The methodology, including software packaged used, is outlined at http://mysite.verizon.net/wz7i/digitalmodes.html Summarizing, I arrived at the following SNR (db) for a character error rate of 5%: AWGN Poor DonimnoEX8 -15.3 -3.1 MFSK16 -14.7 -8.5 PSK31 -13.2 -0.8 Contestia500/16 -14.0 -9.2 RTTY -9.1 +3.7 I probably need to look at Olivia 500/4 These data confirm my prejudice about the excellent performance of MFSK16. With the extended low tones implemented in several packages, the mode is not difficult to tune. A couple things surprised me. I would have expected DominoEX to do better under poor propagation. Another surprise is the difference in performance between different software implementations of a given mode. A software program may have excellent decoding performance with one mode and then have performance with another that is not competitive. The above numerical data would vary a good deal if different decoding software were used. So if you find operating with a given mode frustrating, don't discard it without trying another program. I hope that with RSID some of these excellent modes will find greater use. The web site may well have errors so if you find something surprising, please let me know so I can check things. I don't want to mislead anyone. Wes, WZ7I www.wz7i.com Try Hamspots, PSKreporter, and K3UK Sked Page http://www.obriensweb.com/skedpskr4.html Yahoo! Groups Links -- http://pa0r.blogspirit.com Try Hamspots, PSKreporter, and K3UK Sked Page http://www.obriensweb.com/skedpskr4.html 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: digitalradio-dig...@yahoogroups.com digitalradio-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: digitalradio-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Packet configurations?
a reason for No serial connections... Serial connections are so 1970's. My computer does not even have a serial connection. I'm also a believer in simplicity. Putting on a USB to serial connection is going backwards in the digital revolution. Same with the TNC. It would seem that the simplest configuration would use all the native parts of my netbook to their best advantage (i.e. the sound card) in a digital form. Today I think I should find a configuration where I connect my VX5 to my netbook via a USB cable and software does the rest for the complete packet solution. So far I think I'm a dreamer :-( --- John Becker, WØJAB w0...@... wrote: :No serial connections and no external TNC please. Is there a reason?
[digitalradio] xastir or similar service/daemon 'back end' software?
Is it possible to run xastir (or some other similar aprs software service) on a machine as a service/daemon, and use a different machine to connect to it to view aprs maps? I have an old very slow machine that should be good enough to do the communications and data manipulation, but it is way too slow to view the maps once they are loaded in. (300mhz, 256mb ram) Thanks!
[digitalradio] DX4WIN - rotator interface
the info on the DX4WIN software says it is compatible with the sartek and hygain rotator interfaces. the sartek is not available anymore. I have the yaesu 2800 DXA rotator and a HAM IV rotor. what rotor interface can I use for DX4WIN? Is the idiom Press unit compatible or something else? Thanks, Fred VE3PIE
[digitalradio] Re: SDR-Radio with DM780 20M Digital Band
Patrick Although the amount of RAM may not be critical (provided you're not paging), the SPEED of the memory is probably the limiting factor. The summary is that in a modern cpu with multiple cores and pre-fetch pipeline processing, the processor can execute instructions faster than they can be retrieved from main memory. Access to the L1/L2/L3 caches is much faster than access to main memory, so designing a program so that as much of it and it's working memory will fit into the cache as possible can make a big difference to performance. What this means for the discussion is that when comparing PCs, don't look just at the cpu speed and amount of RAM; consider the speed of the RAM too. I'm getting ready to buy a new PC now and it having DDR3 memory is more impotent to me than the highest possible cpu speed. Sources - this presentation explains a lot about modern PC architecture and performance: http://www.infoq.com/presentations/click-crash-course-modern-hardware If you really want the nitty-gritty, take a look at this classic paper, which is LINUX oriented, but still applies to a Windows PC: What every programmer should know about memory http://people.redhat.com/drepper/cpumemory.pdf John - K6CKP --- In digitalradio@yahoogroups.com, Patrick Lindecker f6...@... wrote: Hello Tony, According to my tests, it is only the capacity to do calculations which is the key, as a lot of digital processng is done (for example for SDR or Panoramics). I don't think RAM is important. I mean either you have sufficient memory or you have not (and you will have a message error). But if you have enough, having double or four more that the minimum does not change anything. Note: with or without BPSK31 panoramic, I have about 2 % of CPU usage. 73 Patrick - Original Message - From: Tony To: digitalradio@yahoogroups.com Sent: Saturday, January 30, 2010 4:35 AM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Patrick, Thanks for the information. As you may have read from my reply to Andy, my CPU usage seems to be very low with Multipsk. It's well below 10%. Is there a particular Multipsk mode or configuration that would tax the system? I'd like to try it and see how it affects CPU usage. Merci mon ami... Tony -K2MO - Original Message - From: Patrick Lindecker To: digitalradio@yahoogroups.com Sent: Friday, January 29, 2010 4:51 PM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Hello Tony, I have here two PC XP at about 2.4 GHz (single core): I have compare these two XP computers on the same file to decode (in 110A): * the first one (the oldest) which is an AMD Atlon 2500+ 1.09 GHz 768 Ko RAM takes 75 seconds to decode it, * the second one which is an AMD Atlon 2400+ 2 GHz 736 Ko RAM takes 20 seconds to decode it. On the most modern (about 3 years old) with SdR and RS ID detection on 44 KHz, the CPU load is about 35 to 40 %, but on the old one it is 100 % (the program does not work in fact). So normally with a modern PC it is OK. With an old PC, it can be problematic. Note: with my Vista laptop (dual core), the CPU load is about 25 % in the same conditions. 73 Patrick - Original Message - From: Tony To: digitalradio@yahoogroups.com Sent: Friday, January 29, 2010 8:36 PM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Andy, I plan on switching to SDR in the near future. My current PC is a dual CPU 2.2GHz Dell with 3 GHz RAM. Any idea what the minimum PC requirement is to run Multipsk with SDR? Could you also tell us what processor you're running now? Thanks, Tony -K2MO - Original Message - From: Andy obrien To: digitalradio Sent: Friday, January 29, 2010 9:11 AM Subject: [digitalradio] SDR-Radio with DM780 20M Digital Band One of the things that I wanted to accomplish with an SDR receiver, is the ability to keep an eye on the whole 14065 to 14115 frequency range. If I was down on 14074 monitoring ALE 400 traffic, I would miss Olivia signals that popped up in the 14109 area. I would also miss Hell signals at 14068. Now the SDR affords the opportunity to keep an eye all all at once. My venture in to SDR from a digital mode perspective has led to a discovery that, other than Multipsk, the current state of the art does not support direct monitoring of wider I/Q data. I'm also challenged in that my PC cannot cope with the Multipsk CPU demand when I try direct monitoring. So, at the moment I am visually monitoring signals with the SDR and using traditional software methods
[digitalradio] Join us for HSMM-MESH Networking Webinar Saturday, Feb. 6, 2010
Please disseminate to all ham club members. HSMM-MESH(tm) Networking Seminar The HSMM-MESH(tm) Networking Seminar will cover all aspects of the HSMM-MESH software developed in Austin, TX. The Webinar will begin with an explanation of High-Speed Multi-Media (HSMM) and the subset of this topic which uses modified Linksys WRT54GL 2.4 GHz Wireless Routers to form a mesh network, handy for high speed digital communications in the ham band - for emergencies, special events and field day. The Webinar will cover applications, antennas, hardware, and the software. You will learn how to load the software and how to configure it. In the second part there will be a lab where we will actually load the software into a router and configure the router. You will need a Linksys WRT54GL (any version) or a WRT54G (Version 1.1 through 4 - version 5 or higher will NOT work.) The Webinar will be online at 8:00am Central time to give you a chance to get logged in and test your setup before something starts happening. Training starts at 9:00am with 10 minute breaks about every hour. And we will finish in the afternoon after a lunch break. You should Register before Saturday morning if possible. . If you have a microphone and headset you will be able to ask questions verbally over VOIP. Otherwise you can type in questions to be able to interact with the speaker. The Webinar is provided through the courtesy of Ham-Com and is presented by members of the NTMS-HSMM and Austin-HSMM groups. (contact...@kdream.com) hsmm-mesh.org Join us for a Webinar on February 6 https://www1.gotomeeting.com/register/959766065 *Space is limited.* Reserve your Webinar seat now at: https://www1.gotomeeting.com/register/959766065 HSMM-MESH *Title:*HSMM-MESH(tm) Networking Seminar *Date:* Saturday, February 6, 2010 *Time:* 9:00 AM - 3:00 PM CST After registering you will receive a confirmation email containing information about joining the Webinar. *System Requirements* PC-based attendees Required: Windows® 2000, XP Home, XP Pro, 2003 Server, Vista Macintosh®-based attendees Required: Mac OS® X 10.4 (Tiger®) or newer
Re: [digitalradio] Re: SDR-Radio with DM780 20M Digital Band
Hello John, Although the amount of RAM may not be critical (provided you're not paging), Yes I agree. the SPEED of the memory is probably the limiting factor. It could explain why my two PC at 2400 MHz have very different calculation speeds (a ratio larger than 2), the oldest being the slowest (as in real life). Thanks for the explanations and the WEB addresses. 73 Patrick - Original Message - From: jcprout jcpr...@gmail.com To: digitalradio@yahoogroups.com Sent: Monday, February 01, 2010 9:45 PM Subject: [digitalradio] Re: SDR-Radio with DM780 20M Digital Band Patrick Although the amount of RAM may not be critical (provided you're not paging), the SPEED of the memory is probably the limiting factor. The summary is that in a modern cpu with multiple cores and pre-fetch pipeline processing, the processor can execute instructions faster than they can be retrieved from main memory. Access to the L1/L2/L3 caches is much faster than access to main memory, so designing a program so that as much of it and it's working memory will fit into the cache as possible can make a big difference to performance. What this means for the discussion is that when comparing PCs, don't look just at the cpu speed and amount of RAM; consider the speed of the RAM too. I'm getting ready to buy a new PC now and it having DDR3 memory is more impotent to me than the highest possible cpu speed. Sources - this presentation explains a lot about modern PC architecture and performance: http://www.infoq.com/presentations/click-crash-course-modern-hardware If you really want the nitty-gritty, take a look at this classic paper, which is LINUX oriented, but still applies to a Windows PC: What every programmer should know about memory http://people.redhat.com/drepper/cpumemory.pdf John - K6CKP --- In digitalradio@yahoogroups.com, Patrick Lindecker f6...@... wrote: Hello Tony, According to my tests, it is only the capacity to do calculations which is the key, as a lot of digital processng is done (for example for SDR or Panoramics). I don't think RAM is important. I mean either you have sufficient memory or you have not (and you will have a message error). But if you have enough, having double or four more that the minimum does not change anything. Note: with or without BPSK31 panoramic, I have about 2 % of CPU usage. 73 Patrick - Original Message - From: Tony To: digitalradio@yahoogroups.com Sent: Saturday, January 30, 2010 4:35 AM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Patrick, Thanks for the information. As you may have read from my reply to Andy, my CPU usage seems to be very low with Multipsk. It's well below 10%. Is there a particular Multipsk mode or configuration that would tax the system? I'd like to try it and see how it affects CPU usage. Merci mon ami... Tony -K2MO - Original Message - From: Patrick Lindecker To: digitalradio@yahoogroups.com Sent: Friday, January 29, 2010 4:51 PM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Hello Tony, I have here two PC XP at about 2.4 GHz (single core): I have compare these two XP computers on the same file to decode (in 110A): * the first one (the oldest) which is an AMD Atlon 2500+ 1.09 GHz 768 Ko RAM takes 75 seconds to decode it, * the second one which is an AMD Atlon 2400+ 2 GHz 736 Ko RAM takes 20 seconds to decode it. On the most modern (about 3 years old) with SdR and RS ID detection on 44 KHz, the CPU load is about 35 to 40 %, but on the old one it is 100 % (the program does not work in fact). So normally with a modern PC it is OK. With an old PC, it can be problematic. Note: with my Vista laptop (dual core), the CPU load is about 25 % in the same conditions. 73 Patrick - Original Message - From: Tony To: digitalradio@yahoogroups.com Sent: Friday, January 29, 2010 8:36 PM Subject: Re: [digitalradio] SDR-Radio with DM780 20M Digital Band Andy, I plan on switching to SDR in the near future. My current PC is a dual CPU 2.2GHz Dell with 3 GHz RAM. Any idea what the minimum PC requirement is to run Multipsk with SDR? Could you also tell us what processor you're running now? Thanks, Tony -K2MO - Original Message - From: Andy obrien To: digitalradio Sent: Friday, January 29, 2010 9:11 AM Subject: [digitalradio] SDR-Radio with DM780 20M Digital Band One of the things that I wanted to accomplish with an SDR receiver, is the ability to keep an eye on the whole 14065 to 14115 frequency range. If I was down on 14074 monitoring ALE 400 traffic, I would miss Olivia signals that popped up in the 14109 area. I would also
Re: [digitalradio] Re: Comments PA0R / PSK MAIL ARQ / ALE 400 ARQ FAE
Rein PA0R wrote: What I don't understand is why NOBODY uses the pskmail arq chat mode Why accept 5% error when you can have it 100% error free? Patrick's ALE-400 FAE ARQ is another mode that falls into this category Rein. Like PSKMail, it sees little use as an ARQ chat mode. A nice thing about ARQ besides the error-free throughput, is that there's no need wait for the other station to un-key in order to change the subject or inject a comment. Patrick's use of FAE (Fast Acknowledgment Exchange) allows for ACKS / NACKS every 6 to 7 seconds. Another advantage of ARQ is that it can check for errors that occur as the band changes. With non-ARQ modes, data can be lost during long key downs and the sending station has no way of knowing that. With ARQ, the constant exchanges let the sending operator know if the data is getting through. I wrote an ALE-400 chat mode guide for for the group some time ago and it seemed to catch on for a while (see below). A setup guide for PSKMail chat mode might help. Tony -K2MO Quick Start Guide For ALE-400 Multipsk Download Site : http://f6cte.free.fr/index_anglais.htm Installation: Note. Do not install the program from the desktop. Copy the Multipsk ZIP file to a temporary folder and click the INSTALL.EXE file. By default, the program will be installed in the Multipsk folder. Configuration: The program should open the configuration screen on the first installation. If not, click CONFIGURATION located in the upper left corner of the main window and click CONFIGURATION SCREEN. In the CONFIGURATION SCREEN. Click SERIAL PORT to select your PTT COM PORT (or VOX) Click OPTIONS FOR SERIAL PORTS (if additional settings are needed) Click SOUND CARD INPUT / OUTPUT to configure your sound card Click RX/TX SCREEN button to return to main window Entering Your Personal Information: In the upper left corner of the main window, click CONFIGURATION / PERSONAL DATA. Enter your call sign, name, locator and so on - click save. RSID Management: Click CONFIGURATION / MANAGEMENT OF THE IDENTIFIERS Click TRANSMISSION OF YOUR CALL SIGN + LOCATOR in the popup window. At the top of this window, click CONTINUOUS under DETECTION MODE. Click QUIT to return to the main program window. * Call sign and locator will be taken from the information previously entered in the PERSONAL DATA window. It is important to follow the setup sequence. Reed Solomon Identifiers: The RS ID buttons are located in the upper left side of the main program window just above the waterfall. These indentifiers will remain active once clicked. Unclick to deactivate. RSID - this transmits the Reed Solomon mode identifier when clicked. It lets others know what mode you are transmitting. In ALE400, the Reed Solomon ID is automatically sent so this button stays in use. RX RSID - when active, this button allows Multipsk to automatically switch modes upon RSID reception. RX CALL ID - activates the reception of the CALL ID allowing you to see the other stations call sign and locator or CALL ID. It will appear inside the waterfall once decoded. Sending the CALL ID Clicking the CALL ID button (located on the far left of side of the main window) will SEND your CALL ID which is your call sign and locator. It will appear in the waterfall at the receiving station. RSID Map Activation: The Multipsk Map will automatically display upon the reception of the transmitting stations CALL ID and will show that stations location on the map. Waterfall: Waterfall controls are located on the right side of the main window. Make sure WATERFALL / HIGH is clicked for best results. Adjust the waterfall color and contrast using the up/down COLOR buttons. Appearance: Font type, color and window size buttons are located on the bottom left of the main window. Click FONTS / HEIGHT to adjust to your preference. Macros Patrick has already configured the Multipsk macros. The user information for each macro is taken from the PERSONAL DATA where your call sign, name and locator are stored. If you'd like to customize the macros, right click on the macro buttons. Remember to click SAVE AND CLOSE when finished. Using the ALE-400 ARQ FAE CHAT MODE In the main window, click on ALE-400 mode (not 141A ALE) and the ARQ FAE button located in the middle of the window (buttons stay pushed in). The official 20 meter ALE-400 calling frequency is 14074.0 DIAL. Offset it fixed at +1625Hz. Click the CQ button next to ARQ FAE button to send a CQ. The CQ will go out as soon as the button is pressed; transmitting 6 seconds and listening for 7 seconds. To end the call, click the END button next to the CQ button. Note - the CQ must finish before you can end the call. Multipsk will connect automatically once the ALE-400 signal is detected by another station (ANSWER button must be clicked). The stations call sign will appear in the RX window confirming a connection. The PC speaker will BEEP to
[digitalradio] Re: Performance of modes: weak signal and poor ionospheric conditions
I'm pretty darn happy with the performance of Olivia without the added
complexity of ARQ and the one on one aspect of the ARQ protocals.
I'm not sure about pskmail arq chat mode, but some of the other ARQ protocals
I've played with look like a mess when you're a station on the outside looking
in... that's something I really never liked about any of the ARQ/handshaking
modes. It's like you're turning your little channel into a private line.
FLDIGI has the WRAP checksum feature which allows an unlimited number of
receiving stations to confirm 100% from a single uninterrupted transmission.
And stations that don't have WRAP get to see the message too.
-Dave, KB3FXI
--- In digitalradio@yahoogroups.com, Rein Couperus r...@... wrote:
What I don't understand is why NOBODY uses the pskmail arq chat mode, which
adds
an ARQ layer to modes like PSK250R, THOR22 or MFSK32.
Why accept 5% error when you can have it 100% error free? Are you afraid your
typing errors get to the other end undamaged?
Rein PA0R
MFSK16 always seems to come up near or at the top of the simulated tests
but I can't duplicate that in the real world.
My experience is that Olivia 8/500 does as well if not better and gives
MUCH greater latitude in tuning while still providing 100% copy under
moderate to poor conditions. Olivia 16/500 is much slower but goes way
into the noise where I've had terrible results with MFSK16 under the same
conditions. And if 8/250 Olivia (slower yet) doesn't do it, I just turn
off the HF rig.
BTW, my experience is almost all on 80m with NVIS antennae.
-Dave, KB3FXI
--- In digitalradio@yahoogroups.com, Wes Cosand wes.cosand@ wrote:
I have finished a series of simulations looking at the performance of
several modes that seemed appropriate for extended keyboard to
keyboard rag chew QSOs. I was looking at modes that offered a
throughput of about 40 wpm so they could keep up with a reasonable
typist with a bandwidth of no more than 500 hz.
I used PathSim to measure accuracy of text transmission under white
noise and CCIR 520-2 Poor simulated propagation conditions. I
measured text accuracy over at least seven minutes of text for each
data point.
The graph can be found at
http://mysite.verizon.net/wz7i/modeimages/Digital%20Modes%20Poor%20Condx.png
The methodology, including software packaged used, is outlined at
http://mysite.verizon.net/wz7i/digitalmodes.html
Summarizing, I arrived at the following SNR (db) for a character error
rate of 5%:
AWGN Poor
DonimnoEX8 -15.3 -3.1
MFSK16 -14.7 -8.5
PSK31 -13.2 -0.8
Contestia500/16 -14.0 -9.2
RTTY -9.1 +3.7
I probably need to look at Olivia 500/4
These data confirm my prejudice about the excellent performance of
MFSK16. With the extended low tones implemented in several packages,
the mode is not difficult to tune.
A couple things surprised me. I would have expected DominoEX to do
better under poor propagation. Another surprise is the difference in
performance between different software implementations of a given
mode. A software program may have excellent decoding performance with
one mode and then have performance with another that is not
competitive. The above numerical data would vary a good deal if
different decoding software were used. So if you find operating with
a given mode frustrating, don't discard it without trying another
program.
I hope that with RSID some of these excellent modes will find greater use.
The web site may well have errors so if you find something surprising,
please let me know so I can check things. I don't want to mislead
anyone.
Wes, WZ7I
www.wz7i.com
Try Hamspots, PSKreporter, and K3UK Sked Page
http://www.obriensweb.com/skedpskr4.html
Yahoo! Groups Links
--
http://pa0r.blogspirit.com
Re: [digitalradio] Re: Performance of modes: weak signal and poor ionospheric conditions
Hey Dave! Would it then be a fair assumption that you would not care for the likes of ALE, DRM, PACTOR, Digi SSTV, Analog SSTV, the new sparky offering called WINMOR, ALE400 - they're pretty much a Closed Club, or Private Channel affair, wouldn't you say? I think there's some others, but suffice it to say.. OH! I just remembered one candidate - DSTAR! The 145.350 Repeater in Cincinnati went DSTAR and poof! Now many ops are odd man out. Howard W6IDS Richmond, IN EM79NV - Original Message - From: kb3fxi kb3...@yahoo.com To: digitalradio@yahoogroups.com Sent: Monday, February 01, 2010 11:40 PM Subject: [digitalradio] Re: Performance of modes: weak signal and poor ionospheric conditions I'm pretty darn happy with the performance of Olivia without the added complexity of ARQ and the one on one aspect of the ARQ protocals. I'm not sure about pskmail arq chat mode, but some of the other ARQ protocals I've played with look like a mess when you're a station on the outside looking in... that's something I really never liked about any of the ARQ/handshaking modes. It's like you're turning your little channel into a private line. FLDIGI has the WRAP checksum feature which allows an unlimited number of receiving stations to confirm 100% from a single uninterrupted transmission. And stations that don't have WRAP get to see the message too. -Dave, KB3FXI SNIP SNIP
