The details for September 25, 2016 can be viewed here.
The UTC amateur registration database is here. Even if you don’t think you will use these bands, REGISTER! Doing so prevents UTC from future PLC coordination in these bands near your QTH. While amateur interference to PLC systems is a myth and PLC systems are migrating away from RF, there is no reason to give them a reason to do something weird in the future.
Click here to view the proposed “considerate operators” frequency usage guide for 630-meters under Part-97 rules that was developed with the input of active band users. This is intended as a guide for new users showing up on the band. (updated: graphic only)
The storm system bisecting North America has not moved much and this morning storms remain active from New Mexico and West Texas into the Plains states. Active morning storms are present along the Gulf Coast and remnants of Hurricane Maria continue to create some noise for the East coast.
Geomagnetic conditions are at quiet to elevated-quiet levels ahead of the next disturbance according to Solarham. The Bz has been variable through the session but it currently at unity this morning. Solar wind velocities are up slightly from the previous session, averaging near 375 km/s. DST values have improved with both indicators touching or exceeding the centerline into positive territory. The Kyoto measurement has begun to exhibit signs of a downward trend, however.
Brian, WA1ZMS / WD2XSH/31, reported on the 600-meter research group that he would be active with a CW beacon on 477.9 kHz using about 75-watts into a Marconi-T antenna.
Roelof, PA0RDT, reported that Joe, VO1NA, was easily audible today on 477.7 kHz CW after high noise impeded reception in the previous session.
Trans-Atlantic WSPR report details can be viewed here.
Jan, PA3ABK, received three reports from Dave, AA1A / WD2XSH/17, for the solitary trans-Atlantic WSPR reports of the session. Jan indicates that he was using just 100-watts from a GW3UEP amplifier and attributes the reports to low noise in North America.
Doug, K4LY / WH2XZO, reported poorer conditions compared to the previous session in the Southeast. He provided reports for nine WSPR stations and he received reports from 29 unique stations. Doug added, “No Hawaii and no VE6/7.”
David, N1DAY/ WI2XUF, reported that “After a little antenna maintenance I was back on the air with a total of 36 unique spots last night. 8 receive and 28 transmit. Some QRN here last night. An average night for WI2XUF.”
Al, K2BLA / WI2XBV, indicates moderate noise in Florida this morning. He provided reports for ten WSPR stations including two reports of WH2XCR. He also reported my CW signal at RST 559.
Mike, WA3TTS, reported that he decoded eleven WSPR stations overnight, but indicates that he missed WD2XSH/15, which “must be prop angle or just out of phase.” Mike indicates that he used the E-probe early in the session, switching to the EWE antennas later in the session, from Southwest to Northwest. Also noteworthy, Mike reported “38 XGP decodes best -11 0842, 50 XXP decodes best -14 0942, 29 ZF1EJ decodes best -16 0234.”
Dave, N4DB, reported that he decoded ten WSPR stations through moderate QRN as off shore noise from the Maria remnant continues to churn.
Trans-Pacific report details, excluding KL7 and KH6, can be viewed here.
Roger, VK4YB, indicates that the band was at “Code 3” levels this morning, meaning that it really wasn’t very good for long haul trans-Pacific paths. Roger added that he experienced “Heavy QRN, strong “Mackerel Sky”. Propagation limited to a narrow beam to the PNW, but strong in that region, -9dB with Larry, W7IUV.” He received reports from CF7MM, JA3TVF, KJ6MKI, N6GN, N6SKM, VE6JY, VE6XH, VE7BDQ, W6SFH, W7IUV, WA6OURWIKI, WG2XSV and WI2XJQ. He shared two-way reports with WH2XCR and WH2XGP.
Neil, W0YSE/7 / WG2XSV, reported that he was decoded by nineteen unique stations. He added that,
“I think N6CVO is a new one. Here are those over 1000 km from me:
…and I heard only 5 unique stations ( +1 bogus ). My best catch was Roger, VK4YB (3 times). The decode of -33 seems to indicate low QRN at that time of the night.
My RXing was with my Eprobe. The vertical does not do as well, which is why I am back to using it just for transmitting.
I also got at least 13 decodes (so far) of VE7BDQ’s JT9. Best is -15, but still coming in at 1222z.”
Ken, K5DNL / WG2XXM, reported that he decoded nine WSPR stations and he received reports from 52 unique stations including VK4YB and six Canadian stations. He shared two-way reports with WH2XCR and ZF1EJ.
Ward, K7PO / WH2XXP, received reports from 54 unique stations including VK4YB, VK2XGJ and VK2EIK.
Larry, W7IUV / WH2XGP, provided reports for nine WSPR stations and he received reports from 44 unique stations including VK2EIK and VK2XGJ. He shared two-way reports with VK4YB. As W7IUV, Larry provided reports for nine WSPR stations including VK4YB..
Recently Andy, KU4XR, experienced quite a bit of success with his receive system on 630-meters with many reports of Roger, VK4YB. I asked Andy to send me some pictures and information about his system as there have been a number of inquiries. Andy’s next step is getting this system ready to transmit so it can safely handle power.
I briefly called CQ on 474.5 kHz CW during the evening before transitioning to WSPR at 0036z. I had a headache so listening to the noise wasn’t in the cards. WSPR reports suggest that the band was in pretty good shape with reports for and from all over North America. It was a bit noisy for this time of year on some azimuths, however. I QRT’ed at 0304z for the evening. My WSPR transmission report details can be viewed here and my WSPR reception report details can be viewed here.
I called CQ once again this morning on 474.5 kHz at 30 second intervals listening to the East, which was considerably quieter than the West where storms were lined up in New Mexico and West Texas into the Plains. I continued to call until just before 1200z when I QRT’ed for the morning. I received a report from Al, K2BLA / WI2XBV, in Florida at RST 559. I also received reports on the Reverse Beacon Network from VE6WZ (thanks to Roger, VE7VV, for sending me the capture and letting me know – I forgot to check!):
The final call sign is one of the decode problems that occurs some times with CW skimmer but it heard me correctly in the other two reports so I am happy about that. It also thinks that I am on 474.2 kHz but that is probably just an offset issue.
Regional and continental WSPR breakdowns follow:
Eden, ZF1EJ, provided reports for six WSPR stations. He received reports from 27 unique stations. Eden shared two-way reports with WH2XCR.
Laurence, KL7L / WE2XPQ, indicates that it was a very poor night where the “band too quiet.” He only shared two-way reports with WH2XCR. Report details can be viewed here.
Merv, K9FD/KH6 / WH2XCR, provided reports for twelve WSPR stations including VK3HP and VK5FQ. He shared two-way reports with VK4YB, ZF1EJ, ZL1EE and WE2XPQ. Merv received reports from thirty unique stations including JA1NQI, JA1PKG, JA3TVF, JH3XCU, VK2EIK, VK2XGJ, VK7TW, ZL4EI and ZL2AFP. DX report details can be viewed here.
Jim, W5EST, presents, “CAN MULTIPATH ACROSS EQUATORIAL ANOMALY HELP EXPLAIN STRONG 630M SIGNALS BETWEEN W/VE AND VK/ZL?”:
“Today’s Pacific Ocean illustration imagines VK/ZL – W/VE propagation encountering arch-shaped upward ionospheric reflecting upraised E-region contour surfaces along the equatorial zone. Various orientations of reflecting contour surfaces allow several ways for 630m RF rays to connect far remote low power stations across the Pacific in deep nighttime.
In this concept, up to 6 RF rays with comparable electric field strengths occasionally constructively interfere to provide about 15 dB of signal advantage compared to the power in electric field of ordinary mid-latitude 630m propagation. Signal advantage in dB is estimated as 10 log10 (6×6) = 15.5 dB.
The RF paths of the rays slowly vary in path length with variable relative phasing, giving rise to QSB fadeups familiar to the 630m operators involved. I imagine one or more of the rays chordally reflect from below across and inside the equatorial anomaly. That way, such chordally reflected rays benefit from one less surface reflection on their way as well.
The second illustration represents the results of my statistical modeling (green, Endnote 1*) of proportions of bar-charted SNRs. This post is a sequel to http://njdtechnologies.net/092017/ . Today’s model results compare with numbers of actual decodes obtained on the VK4YB-w7iuv path, among their three methods used to probe the TP path. The model-predicted proportions (Endnote 2**) at various SNRs were somewhat more optimistic (Endnote 3***) than the actual results during the 36 days of WSPR decodes.
This 6-ray equatorial anomaly propagation concept is but one candidate explanation among several that might be put forward. Modeling can provide some support for the concept, but does not rule outother candidate 630m TP propagation concepts, like ducting between E and F-region, or maybe a couple of hops of F-skip near the equator.
TU & GL with trans-Pacific propagation!”
* Endnote 1: I found that about 6 RF rays were needed to obtain or match to the stronger SNRs that reached -10dB and even peaked at -8dB. The model uses imputed WSPR decoder decode probabilities that strongly sculpt the distribution at various SNRs near WSPR decode threshold. I put in probability values that were consistent with -30dB: 34/100 and -31dB: 6/100 from http://destevez.net/2016/10/simulating-jt-modes-how-low-can-they-get/ (scroll 20%, WSPR section). I searched for probability curves on the WSPR web site, and until I find some, I’ve entered placeholder values.
**Endnote 2: The model I implemented in Excel obtains an estimated probability density distribution of the 6 RF rays combined (spreadsheet available on request). This distribution method is a statistical way of representing 630m QSB. The method performs a 6-fold convolution of the probability density distribution of one sine wave f(x) = 1/[π sqrt(1-x2)] (derivative of arcsine) for each of six instances of equal strength signals. For the modeling, f(x) was evaluated in 0.05 steps from
-.95 <= x <= +0.95.
“Convolution” sounds complicated, but here it’s simply the process of figuring the probability of each possible particular value of total electric field strength at the RX antenna. A 2-fold convolution slides the probability density distribution past the reverse of itself. At any one position of sliding, the probability is the sum of products of multiplying probability densities of each pair of electric field values that can add up to such particular value. You do that multiplying because the probability of independent random values adding up to the particular value is found by multiplying probability of the independent values together. The process is like figuring the probability of throwing two dice and you want to know the probability of a total of 7, for instance, with 7=1+6, 2+5, 3+4.
The model imagines 630m propagation is rolling 6 specially weighted dice, each individual die equally favoring its “1” and its “6”, so to speak, to see what total electric field results. An RF sine wave favors its strongest positive and negative value of electric field strength, as a matter of probability.
When a distribution from 2-fold convolution is found, then that distribution is 2-fold convolved with itself to get a 4-fold convolution. Finally, a 2-fold convolution is convolved with a 4-fold convolution to get a 6-fold convolution. After convolution, the 6-fold convolved probability density result, called g(z), with z=sum of six independent values of random electric field strength x, is checked and normalized for probability 1.0 total area under the curve. Distribution g(z) comes out in 0.05 steps from -5.95 <= x <= +5.95.
The conversion to dB of signal strength remaps the probability density g(z) function of rms electric field strength to be a function of signal power zdB by z = 10^(zdB /20) . The remapped distribution becomes h(zdB) = [(ln10) /20] . z . g(z) = (2.3/20) 10^(zdB /20) g[10^(zdB /20)].
zdB for probability distribution h(zdB) was associated to WSPR SNR by using 0dB for the -24dB SNR frequently observed on the VK4YB-w7iuv path according to the formula zdB = SNR – (-24dB).
A column of WSPR decoder decode probabilities is multiplied value by value with corresponding h(zdB) to get a distribution U(zdB) of actual decodes. One graphs the results in Excel by setting up a column of SNRs next to a column of U values. Block out both columns with mouse, and scatterplot them with respect to each other using the Scatterplot menu item. Convert to a horizontal bar chart by then clicking its horizontal bar chart menu item.
***Endnote 3: Possible reasons the model fails to account for discrepancies may include: 1) Over the 36 days, on some days propagation conditions were poorer than other days, dragging the actual distribution down. 2) Prop conditions trended upward, and the model assumes they were steady. 3) An observed statistical distribution usually fails to exactly match a predicted one due to statistical fluctuation, called sampling error. The model calculations did not include a test of statistical significance to decide whether the observed distribution is significantly unrelated to the model distribution.
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com)!