[digitalradio] WOLF (Weak-signal Operation on Low Frequency)
from http://www.scgroup.com/ham/wolf.html WOLF WOLF (Weak-signal Operation on Low Frequency) is a proposed new signal format and protocol designed specifically for the LF bands. It can be used for beacons and for two way communication. Unlike existing formats, which are optimized for a particular S/N (and corresponding speed), WOLF can operate over a wide range of signal levels. For example, a WOLF beacon transmits a 15-character message repeatedly. If the received signal would be adequate for conventional CW, copy will be displayed in 24 seconds. At a level barely enough for 0.4 WPM QRSS, copy will appear within two minutes. Even if the signal is another 10 dB weaker, the message can still be received. It will take from 20 minutes to several hours, depending on the stability of the Tx and Rx. Of course, it is also necessary that the propagation path remain open over the required interval. I hope that WOLF will permit a QSO to be completed in an hour, if one station receives a signal that is 10 dB weaker than would be needed for QRSS, and the other station's signal is 6 dB below the QRSS threshold. I believe that it is also feasible to hear a LOWFER beacon across the Atlantic, during an overnight run (very accurate time and frequency control is required). At this time, I have implemented only a crude off-line demo. In transmit mode, this command line program writes a .wav file which contains the specified message. A simulation is performed by mixing (using an audio editor) a small amount of this signal with a large amount of noise (recorded off the air or synthetic, as desired). The resulting file is read by the program in receive mode, and attempts to decode the message are made at various intervals. For an on-the-air test, the transmit output file is played (with a media player or editor), feeding the audio into an SSB transmitter. There are also various ways to drive a PSK transmitter. The receiving station records the Rx output as a .wav file, which is then supplied to WOLF for decoding. There have been a few successful WOLF transmissions; simulated results have also been quite encouraging. I used the procedure developed by Lyle Kohler; see his description and results http://www.computerpro.com/%7Elyle/weaksigs/weaksigs.htm. Lyle's tests found that conventional CW could be received with the signal attenuated up to 18 dB below the reference noise level. For 0.4 WPM QRSS, the limit was -30 dB. BPSK at MS1000, ET1 was the most robust mode tested, showing intermittent copy after many minutes at -33 dB. WOLF occasionally shows good copy at -45 dB, and seems quite robust at -40. -- - and http://www.mlecmn.net/~lyle/wolf/wolf4beginners.htm WOLF for beginners -- Andy K3UK
Re: [digitalradio] WOLF (Weak-signal Operation on Low Frequency)
Hi Some more info about wolf http://freenet-homepage.de/dl4yhf/wolf/index.html 73 de LA5VNA Steinar Andrew O'Brien wrote: from http://www.scgroup.com/ham/wolf.html WOLF WOLF (Weak-signal Operation on Low Frequency) is a proposed new signal format and protocol designed specifically for the LF bands. It can be used for beacons and for two way communication. Unlike existing formats, which are optimized for a particular S/N (and corresponding speed), WOLF can operate over a wide range of signal levels. For example, a WOLF beacon transmits a 15-character message repeatedly. If the received signal would be adequate for conventional CW, copy will be displayed in 24 seconds. At a level barely enough for 0.4 WPM QRSS, copy will appear within two minutes. Even if the signal is another 10 dB weaker, the message can still be received. It will take from 20 minutes to several hours, depending on the stability of the Tx and Rx. Of course, it is also necessary that the propagation path remain open over the required interval. I hope that WOLF will permit a QSO to be completed in an hour, if one station receives a signal that is 10 dB weaker than would be needed for QRSS, and the other station's signal is 6 dB below the QRSS threshold. I believe that it is also feasible to hear a LOWFER beacon across the Atlantic, during an overnight run (very accurate time and frequency control is required). At this time, I have implemented only a crude off-line demo. In transmit mode, this command line program writes a .wav file which contains the specified message. A simulation is performed by mixing (using an audio editor) a small amount of this signal with a large amount of noise (recorded off the air or synthetic, as desired). The resulting file is read by the program in receive mode, and attempts to decode the message are made at various intervals. For an on-the-air test, the transmit output file is played (with a media player or editor), feeding the audio into an SSB transmitter. There are also various ways to drive a PSK transmitter. The receiving station records the Rx output as a .wav file, which is then supplied to WOLF for decoding. There have been a few successful WOLF transmissions; simulated results have also been quite encouraging. I used the procedure developed by Lyle Kohler; see his description and results http://www.computerpro.com/%7Elyle/weaksigs/weaksigs.htm. Lyle's tests found that conventional CW could be received with the signal attenuated up to 18 dB below the reference noise level. For 0.4 WPM QRSS, the limit was -30 dB. BPSK at MS1000, ET1 was the most robust mode tested, showing intermittent copy after many minutes at -33 dB. WOLF occasionally shows good copy at -45 dB, and seems quite robust at -40. -- - and http://www.mlecmn.net/~lyle/wolf/wolf4beginners.htm WOLF for beginners -- Andy K3UK No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.7.0/1682 - Release Date: 20.09.2008 10:24
[digitalradio] Burying digital modes in the road Musical road' hits bum note
Maybe we can embed some PSK31 or Olivia in the road outside ARRL HQ? Andy K3UK US 'musical road' hits bum note It might sound like an idea from a 1960s hippy gathering, but there really is such a thing as a musical highway. A section of Avenue K in a Californian desert town uses grooves cut into the road surface to play the Lone Ranger theme to cars driving along it. But some Lancaster residents are not amused. They say the noise from the road sounds more like a discordant screech than the Rossini overture. Officials have bowed to their views and have agreed to pave over the grooves. The response to the new grooves in Avenue K was immediate. While several Lancaster residents were entertained enough to post footage on video-sharing websites such as YouTube, others were less pleased. I think it's terrible because it keeps me awake at night, Lancaster resident Donna Martin told the Daily Breeze newspaper. You can kind of tell it's music, but it's not any tune or notes. It's a scratchy sound, a high-pitch drone. The musical road was the idea of car-maker Honda. The firm said the grooves in the road were engineered to play the overture at perfect pitch for motorists driving Honda Civics at 55mph (88km/h). Similar ideas have been tried out in Japan, South Korea and the Netherlands. But the music was intended only for those inside the cars, so it seems the sound has carried too far. Despite being carved into the road only a couple of weeks ago, officials have announced they will resurface the quarter-mile (400m) strip on Tuesday. --
Re: [digitalradio] Burying digital modes in the road Musical road' hits bum note
That reminds me of a concept where SSTV would be utilized in a backward fashion.. The image sent would be used to modulate the signal, as usual. The difference is that data is in the image, but in order to get it, you have to actually listen to the audio from the signal. Looking at the image would make you think of modern art, perhaps. 73 DE Charles, N5PVL
Re: [digitalradio] Pactor III licensing...
Sorry, Can't do anything with a KAM or PK-232 (any version). Pactor II and III are proprietary modes. Pactor II and Pactor III are only available on the SCS line of modems Cheapest one is the PTC-IIex about $900... Check this web site for their US distributor http://www.farallon.us/webstore/ The PTC-IIex with only Pactor II is $859, with the Pactor III license it's $998. Do you need need all that speed? All Pactor connects start out in Pactor I, and only shift if the higher configuration is available at both ends. What are you going to use it for? Winlink 2000? Dave WB2FTX - Original Message - From: [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Sunday, September 21, 2008 2:54 PM Subject: [digitalradio] Pactor III licensing... I have a KAM XL and a fully tricked out PK232. can either of them be licensed for Pactor III? what is the cost of upgrading to II and to III? thanks chas k5dam -- No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.7.0/1683 - Release Date: 9/21/2008 10:10 AM No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.7.0/1683 - Release Date: 9/21/2008 10:10 AM
Re: [digitalradio] Pactor III licensing...
[EMAIL PROTECTED] wrote: I have a KAM XL and a fully tricked out PK232. can either of them be licensed for Pactor III? what is the cost of upgrading to II and to III? thanks chas k5dam No, it is only for the SCS made boxes. For license details, check http://www.scs-ptc.com 73, Jose, CO2JA
Re: [digitalradio] Pactor III licensing...
David Struebel wrote: Sorry, Can't do anything with a KAM or PK-232 (any version). Pactor II and III are proprietary modes. Pactor II and Pactor III are only available on the SCS line of modems Cheapest one is the PTC-IIex about $900... Check this web site for their US distributor http://www.farallon.us/webstore/ The PTC-IIex with only Pactor II is $859, with the Pactor III license it's $998. Do you need need all that speed? All Pactor connects start out in Pactor I, and only shift if the higher configuration is available at both ends. What are you going to use it for? Winlink 2000? Dave WB2FTX negative, a friend of mine just bought one of the SCS modems for half price and I was wondering whether it was possible to upgrade one of my TNCs. but, as I understand it, they will do Pactor I and that is the standard de rigeur today. thanks chas k5dam
Re: [digitalradio] Pactor III licensing...
Just be careful, the earliest SCS modems didn't have Pactor II or III either. Dave WB2FTX - Original Message - From: [EMAIL PROTECTED] To: digitalradio@yahoogroups.com Sent: Sunday, September 21, 2008 3:26 PM Subject: Re: [digitalradio] Pactor III licensing... David Struebel wrote: Sorry, Can't do anything with a KAM or PK-232 (any version). Pactor II and III are proprietary modes. Pactor II and Pactor III are only available on the SCS line of modems Cheapest one is the PTC-IIex about $900... Check this web site for their US distributor http://www.farallon.us/webstore/ The PTC-IIex with only Pactor II is $859, with the Pactor III license it's $998. Do you need need all that speed? All Pactor connects start out in Pactor I, and only shift if the higher configuration is available at both ends. What are you going to use it for? Winlink 2000? Dave WB2FTX negative, a friend of mine just bought one of the SCS modems for half price and I was wondering whether it was possible to upgrade one of my TNCs. but, as I understand it, they will do Pactor I and that is the standard de rigeur today. thanks chas k5dam -- No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.7.0/1683 - Release Date: 9/21/2008 10:10 AM No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.169 / Virus Database: 270.7.0/1683 - Release Date: 9/21/2008 10:10 AM
[digitalradio] Fw: NBEMS/FLDIGI vs 3.03 - MT63 ops
- Forwarded Message From: David Kleber [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, September 21, 2008 11:43:37 AM Subject: [MT63] NBEMS/FLDIGI vs 3.03 - MT63 ops Hello all, I've done extensive testing with the NBEMS/FLDIGI software and it just keeps getting better and better. The latest version (3.03) now holds the 64 bit interleave (long) setting after program restarts. The latest version of the software can be downloaded here: http://www.w1hkj. com Also, I have a yahoo group setup for sharing information on the use of NBEMS/FLDIGI/ FLARQ and for setting skeds with ops in the Western Pennsylvania area, but anyone, anywhere is welcome to join. Here's some basic info on the setup and tuning procedures for the use of MT63 on NBEMS/FLDIGI: NBEMS/FLDIG - MT63 1K/Long Interleave - Instructions for USB ops (recommended USB frequencies: 3.590, 7.090, 14.109): ### SETUP ### 1) Go to Configure/Modems and click the MT63 tab. 2) Click 64 bit interleave long, save configuration, then close (on vs 3.03 this setting is now saved after restarts of the program). 3) Go to Op Mode/MT63, arrow over and click on MT63 - 1000. ### TUNING ### 1) Tune transceiver to desired HF frequency (always us USB and make sure all DSP, compression and noise blanker settings are disabled). 2) All stations should always center on 1000 Hz on the waterfall (MT63 always uses a bottom freq on 500 Hz on transmit. When you initialize the MT63 modem, the waterfall tx will be set to this default). 3) Click tune button in the upper right corner of the program and let it transmit for about 10 seconds. 4) RX stations center on the received 1000 Hz tone by tuning the receiver VFO. 5) Transmit and receive some text to make sure all stations are tuned and decoding properly. NBEMS/FLDIG - MT63/2K Long Interleave - Instructions for FM 6m/2m/70cm ops: ### SETUP ### 1) Go to Configure/Modems and click the MT63 tab. 2) Click 64 bit interleave long, save configuration, then close (on vs 3.03 this setting is now saved after restarts of the program). 3) Go to Op Mode/MT63, arrow over and click on MT63 - 2000. ### TUNING ### 1) Tune transceiver to desired FM frequency (make sure all DSP, compression and noise blanker settings are disabled and stations operating under weak signal conditions should open the squelch on the transceiver) . 2) All stations should always center on 1500 Hz on the waterfall (MT63 always uses a bottom freq on 500 Hz on transmit. When you initialize the MT63 modem, the waterfall tx will be set to this default). 3) Transmit and receive some text to make sure all stations are decoding properly. Assuming that all soundcards are properly calibrated, no tuning should be necessary. -Dave, KB3FXI
