Re: [digitalradio] Re: IZ8BLY's PSK63F
Skip, It's good to see that there is a correlation between the path simulator results and real world sensitivity testing. White noise tests show that DominoEX4 does have the same 3db sensitivity advantage you mentioned over DominoEX8 and PSK63F. > we did extensive testing this morning on 70cm between PSK63F and DominoEx 4, > and DominoEx4, even under > the severe, fast Doppler shift almost always on that band, was significantly > better copy than PSK63F. The minimum > required S/N of PSK63F compared to > DominoEx 4 also hurt its relative performance compared to DominoEx 4 in > QSB. I can see how the minimum SNR would come into play. I know it's easier said than done, but It would be interesting to repeat the tests while signals were adequately above the minimum SNR threshold required for PSK63F and DominoEX8. That would eliminate any signal strength issues and help reveal the true Doppler performance of each mode. It would help to have a recording of the signals so we can analyze the Doppler spread using a high resolution spectrogram. This would give us a better idea of what's going on and should reveal other frequency shifting characteristics such as aircraft Doppler. It would also be useful to have statistical data on the Doppler spread found on over-the-horizon VHF / UHF propagation. Troposcatter seems to be responsible for daily openings on VHF / UHF. I'll have to look on the net. > If you could make simulation tests between PSK63F, DominoEx 4 and DominoEx 8, > it would help us find > out the best mode to recommend for VHF/UHF. We will be making more real world > tests again this week > on both two meters and 70cm. No problem Skip. Tony -K2MO - Original Message - From: hteller To: digitalradio@yahoogroups.com Sent: Thursday, January 07, 2010 9:17 AM Subject: [digitalradio] Re: IZ8BLY's PSK63F Tony, we did extensive testing this morning on 70cm between PSK63F and DominoEx 4, and DominoEx4, even under the severe, fast Doppler shift almost always on that band, was significantly better copy than PSK63F when signals were just over the noise. The minimum required S/N of PSK63F compared to DominoEx 4 also hurt its relative performance compared to DominoEx 4 in QSB. We did not have time to compare to DominoEx 8, which is roughly the same speed as PSK63F, but our previous tests between DominoEx 4 and DominoEx 8 showed that on VHF and UHF, either SSB or FM, that the 3 dB minimum S/N advantage of DominoEx 4 is very necessary. Signals at 200 miles are almost always just above the noise on SSB phone or DominoEx 4 on 70 cm. That is why operators on those bands are called "weak signal" operators! If you could make simulation tests between PSK63F, DominoEx 4 and DominoEx 8, it would help us find out the best mode to recommend for VHF/UHF. We will be making more real world tests again this week on both two meters and 70cm. 73 Skip KH6TY > __ > 1a. IZ8BLY's PSK63F > Posted by: "Tony" d...@optonline.net kt2q > Date: Mon Jan 4, 2010 12:52 am ((PST)) > > All, > > Recent path simulation tests indicate that Nino Porcino's PSK63F > offers better performance over PSK31 and PSK63 in a couple of areas. > The most significant improvement is it's ability to endure Doppler > spread found on paths that cross the polar ionosphere. Both PSK31 and > PSK63 fail miserably in this area; see high-lat test samples below. > > Path Simulation: High Latitude (Moderate) Path Delay: 3ms, Doppler > spread 10Hz > Pangram Text: Quick Brown Fox > > PSK63F -- the quick brown fox jumps over the lazy dog > PSK63 -- mev roe tt#dtorl|f- bn ô mp e o ihe Fzy dg > PSK31 -- nls oSer Òe naAeta qlipM h nV o T rn agâ o > RTTY -- TH QACKH492, FOJUMP OR THTLAZY G > > Sensitivity-wise, it's quite a bit more sensitivity than PSK63, but > only marginally better than PSK31. Although it's speed is about 25% > faster than PSK31, it's about 40% slower than PSK63. Average wmp rate > seems to be 63 wpm for PSK63F. > > Lowest S/N (sensitivity) > > PSK63F -12db > PSK63 -7db > PSK31 -11db > RTTY -5db > > Additional path tests indicate that PSK31 and PSK63F perform about the > same under moderate mid-latitude conditions (CCIR fading channel). > Tests show that PSK31 and PSK63F will outperform PSK63 when signals > are weak under quiet conditions since they both have greater sensitivity. > > It would be interesting to hear from our HF digital friends up north > who experience the distorting effects of the polar ionosphere on a > regular basis; this is where the PSK63F mode can be put to the test. > > Available software: > > Nino Porcino's Stream -- http://xoomer.virgilio.it/aporcino/ > Patrick Lindeckers Multipsk -- http://f6cte.free.fr/index_anglais.htm > (thanks for including PSK63F Patrick) > > Tony, K2MO > >
[digitalradio] Re: IZ8BLY's PSK63F [3 Attachments]
Phil, > It would be valuable to the community to be able to recognize the presence of > Doppler spread by some visual or > aural means. There are times when the effect can be detected by sight and sound. Even a moderate disturbance in the polar ionosphere can cause enough Doppler spread to make HF voice communications sound hollow or as if the signal was emanating from under water. The same applies to CW and digital mode signals. Visually, narrow band modes like PSK31 will appear dispersed (spread out) compared to others in the waterfall. The individual tones that make up wide-band signals (MFSK) will also appear diffuse. Other visual indications of Doppler induced frequency dispersions caused by signals that propagate over the poles, would be the chaotic movement of the PSK31 tuning indicator. Although there are times when Doppler spread is too small to be detected, it can still cause throughput problems with certain modes. The amount of throughput loss depends on the severity of the Doppler spread and how resistant the mode is to that type of distortion. Narrow modes like PSK10, for example, are especially sensitive to small frequency spreads (1Hz) and can suffer throughput loss on a relatively quiet mid-latitude path. The reflecting surface of the ionosphere is somewhat similar to the surface of a pool of water where waves are traveling in all directions. As sunlight hits the pools surface, the motion of the waves cause the light to scatter at random. With RF waves, the motion of the ionospheric irregularities cause random shifts in frequency creating wavelets around the main signal (see attached: Normal vs. Doppler spread). Doppler spread is more pronounced in the active regions of the auroral and equatorial zones than it is in the mid-latitudes. Its common to see an increase in the effect on long distance contacts since the signal will eventually end up near those regions. How much it effects digital mode throughput depends on the state of the ionosphere and the mode in use. As for PSK63F, it combats this type of distortion much better than standard PSK modes. Tony -K2MO - Original Message - From: Phil Williams To: digitalradio@yahoogroups.com Sent: Tuesday, January 05, 2010 8:49 AM Subject: Re: [digitalradio] IZ8BLY's PSK63F Demonstrating a suite of digital coding methods are vulnerable to Doppler spread does not tell the whole story. What does the signal look like on the a spectrogram when subjected to Doppler spread? Yes, you have incomplete or scrambled text, but then the root cause of that could be anything. It would be valuable to the community to be able to recognize the presence of Doppler spread by some visual or aural means. Armed with this information then one begins to make choices of other modes that would be less vulnerable to the effects of Doppler spread. philw de ka1gmn On Tue, Jan 5, 2010 at 2:13 AM, Tony wrote: Phil, > What about PSKFEC31 under the same test scenarios? Have a look: Path Simulation: High Latitude (Moderate) Path Delay: 3ms, Doppler spread 10Hz Pangram Text: Quick Brown Fox PSK31FEC t e tio E ttaeH loo etee- e e e ˆyaooe n o ao t aeepvede n neete ueeeu .tna0 o een it=pctidr a ieae t e tio E ttaeH loo etee- e e etˆyaooe on oe ne 6etnuEenoel o·b geogtee PSK63F the quick brown fox jumps over the lazy dog the quick brown fox jumps over the lazy dog the quick brown fox jumps over the lazy dog Tony -K2MO - Original Message - From: Phil Williams To: digitalradio@yahoogroups.com Sent: Monday, January 04, 2010 5:16 AM Subject: Re: [digitalradio] IZ8BLY's PSK63F Very interesting. What about PSKFEC31 under the same test scenarios? Certainly, there would be more a in throughput, but that is a matter of some liberal use of CW shorthand. philw de ka1gmn On Mon, Jan 4, 2010 at 2:48 AM, Tony wrote: All, Recent path simulation tests indicate that Nino Porcino's PSK63F offers better performance over PSK31 and PSK63 in a couple of areas. The most significant improvement is it's ability to endure Doppler spread found on paths that cross the polar ionosphere. Both PSK31 and PSK63 fail miserably in this area; see high-lat test samples below. Path Simulation: High Latitude (Moderate) Path Delay: 3ms, Doppler spread 10Hz Pangram Text: Quick Brown Fox PSK63F -- the quick brown fox jumps over the lazy dog PSK63 -- mev roe tt#dtorl|f- bn ô mp e o ihe Fzy dg PSK31 -- nls oSer Òe naAeta qlipM h nV o T rn agâ o RTTY -- TH QACKH492, FOJUMP OR THTLAZY G Sensitivity-wise, it's quite a bit more sensitivity than PSK63, but only marginally better than PSK31. Although it's speed is about 25% faster than PSK31, it's about 40% slower than PSK63. Average wmp rate seems to be 63 wpm for PSK63F. Lowest S/N (sensitivity) PSK63F -12db PSK63 -7db PSK31 -11db RTTY -5db Additional path tests indicate that PSK31 and PSK63F perform about the same under moderat
[digitalradio] CSS to release The PK-232 25th Anniversary Software CD
CSS to release The PK-232 25th Anniversary Software CD Muscle Shoals AL, January 5th 2010: Creative Services Software announced today that ham can pre order the PK-232 25th Anniversary Collectable CD. This collection of software is limited to 10,000 copies. It includes: • PakRatt for DOS • PkFax for DOS • PakRatt Lite • PakRatt 2.3 for Windows • Pkterm ‘99 • Wefax ‘99 • Pacterm for Windows • Wefax for Windows • Radio Operations Center for AEA/Timewave • Wefax Ops for AEA/Timewave • PDF manuals for all the programs are included! This way, those that have lost their manuals can print them out again! Company President Rick Ruhl, W4PC, said, “The conception of the PK-232 in 1985 was a leap forward in Ham technology. For the last 25 years, over 100,000 PK-232 have been sold and tens of thousands are still in use. The re-release of the DOS and Windows 3.1 software, which now all have Y2K fixes, is to show how far development has come since those early days of the PC and the PK-232. These older programs will not be sold separately, but only in this anniversary collection.” CSS and Timewave are also including pictures of older advertisements from AEA and Timewave has given CSS special permission to include PDFs of the AEA catalogs. For ham radio operators, this is a golden opportunity to own a piece of ham history, as the collection will only be available during 2010. Each copy will be numbered and have a certificate of authentication included. A pre-order price of $139.95 is available at the CSS online store at http://www.cssincorp.com. Customers who purchase the pre-order will get the latest copy of Radio Operations Center sent to them along with their special serial number that will work with all the products on the 25th Anniversary collectable. __ Check out the Radio Operations Center for Kantronics and Timewave and Emcomm Ops for the MFJ TNCs at http://www.cssincorp.com
[digitalradio] NZ4O Propagation Forecast #2010-02
The NZ4O Daily LF/MF/HF/6M Frequency Radiowave Propagation Forecast #2010-02 has been published on Friday 01/08/2009 at 1400 UTC, valid UTC Saturday 01/09/2010 through 2359 UTC Friday 01/15/2009 at http://www.wcflunatall.com/nz4o3.htm . 73 & GUD DX, Thomas F. Giella, NZ4O Lakeland, FL, USA n...@arrl.net Suggested frequencies for calling CQ with experimental digital modes = 3584,10147, 14074 USB on your dial plus 1000Hz on waterfall. Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked 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/
