It is my impression that this was an average session, middle of the road and nothing terribly exciting to write home about. Geomagnetic activity continues to be unsettled but in spite of aurora to the North and regional reports of high noise levels, the band was open with a significant number of reports at levels that would yield JT9 QSO’s and many others at CW levels. I used the evening to test some changes to one of my receive antennas and it was a good enough session for that. I admit that I am in withdrawals from my morning CW skeds which I expect will begin again shortly.
The geomagnetic field experienced multiple reporting periods of unsettled conditions with a variable Bz that was South-dominant. Solar wind velocity exceeded 600 km/s for much of the session with a few periods below 500 km/s. DST values suggests disturbed band conditions:
John, WA3ETD / WG2XKA, reports that he was QRT due to weather threats and expects unsettled weather conditions for the next five days. Phil, VE3CIQ, reports a power problem on the WSPR PC so he was inadvertently off air. Roger, VK4YB, and John, VK2XHJ, both report high noise level and storms in their region so the expectation of hearing much is not high. Larry, W7IUV / WH2XGP, also reported very night noise level in Washington state during the evening. There was a new receiving station, however, RTLSDRSPYV, during the session located to the North of Beaumont, Texas on the Texas coast. This station had no reports in the database.
Doug, K4LY / WH2XZO, returned to air during the session running 5-watt TPO from a small broadband amp as he continues to work out antenna problems. Once his antenna is stable again, we can replace the FET in his 100-watt amp and return to full power. Doug waxed poetic with the following comments:
“How beautiful the morning glory vines climbing up my towers, coax and wires- top hat wires once high and proud, now fallen and sagging like a dunce cap. It was the shinning sun that quickly kudzued the natural growth and degraded the unnatural polymer. With uncertain eye and unsteady finger, I shoot an arrow and then another- and like my memories lost in the neuron tangle, the feathered arrow has found a higher home.
The unpoetic reality is I’ve transmitted on 630M again, the first time since spring, but with fewer and lower top hat wires and much less power. I’ve struggled, many hours and days, using an EZ Hang sling shot, not arrows, to replace fallen and failing polypropylene supported top hat wires with dacron. That struggle continues.
The made in U.S.A. amp, a casualty of fallen top hat infinite SWR, is temporarily- all things are temporary- replaced by a Chinese 5-watter. My reported ERP of 200 mw really was 100 mw with a surprising 99 reports by 4 unique stations
Maybe I’ll be ready for the autumn season.”
Neil, W0YSE/7 / WG2XSV, also waxed poetic so there must be something in the water. Neil provided the following comment and statistics:
“…Same song, same verse, not much better, not much worse…..
Hearing: WG2XIQ, WH2XCR, WH2XGP, WI2XJQ
Heard by: N6RY, NO1D, VE7BDQ, W6XY, WH2XGP, WI2XBQ, WI2XJQ
Ho-hum, guess I’ll go back sleep…“
I guess it could be worse…
Larry, W7IUV / WH2XGP, reports that he decoded four WSPR stations and was decoded by fifteen unique stations before a power glitch at 1045z ended his session. As previously noted, Larry reported extremely high noise levels.
Rick, W7RNB / WI2XJQ, reports lots of noise but he decoded three WSPR stations and was decoded by six unique stations:
Regional and continental WSPR breakdowns follow:
There were no reports from the trans-Atlantic, trans-African, or trans-Equatorial paths. UA0SNV was present but no reports have been filed at this time.
In the Caribbean, Eden, ZF1EJ, reported my station during the session:
Laurence, KL7L / WE2XPQ, operated a CW beacon on 474 kHz during the late afternoon and early evening before transitioning to WSPR. Rick, W7RNB / WI2XJQ, listened through Laurence’s sunset but so signals were reported and Rick indicates that his noise level was very high. Laurence had a typical WSPR session in spite of aurora:
Merv, K9FD/KH6 / WH2XCR, had a relatively typical session with stations in North America but noise in Australia severely limited reports in that direction:
Jim, W5EST, continues his recent discussion with, “PART 7 THEORY JUNGLE SAFARI: ANATOMY OF 630m O/X WAVES”:
“Yesterday’s blog reviewed RF electric field sine waves having amplitudes Ex and Ey 90° out of phase, which make an elliptically polarized wave. You can review color animations of linear, circular and elliptical polarizations at: http://cddemo.szialab.org/index.html . O-waves and X-waves in general are two different elliptically-polarized RF waves. Appleton-Hartree (AHL) has an associated polarization ratio formula (Endnote*) stating the only two wave propagations that GMF-permeated plasma will support.
Today’s illustration, at its lower left, adds conjoined half-graphs for the polarization ratios for 630m X-wave and 630m O-wave. These augment the earlier blog graph of plasma frequency vs. altitude vs. paired curves of refractive index n2 confronting 630m RF. Probable E-region altitudes (km) correspond to the various plasma frequencies (electron concentrations).
630m RF propagation (~N/S) along the GMF produces elliptical polarization having equal amplitudes Ex and Ey in 1:1 ratio with +/- sign signifying opposite rotation of electric field around the ray. That’s opposite rotational senses of circular polarization which together produce Faraday rotation of the linear polarization of a vertically polarized 630m TX wave.
Ionospheric plasma faced with 630m RF propagation crosswise (~E/W) to the GMF apparently can support a vertically polarized wave and a horizontally polarized wave if need be to generate the O and X waves and present them with different refractive indices n = sqrt(n2) depicted upper right in today’s graph. However, a 630m TX station generally transmits the vertical polarization only. This leaves open the question of how the 630m power divides, if at all, into O-wave power and the X-wave power with what polarizations. More on that topic can await another blog post.
This theory jungle safari is dangerous and you can easily fall into a trap. Avoid the trap of misreading the polarization ratio graph. The upper X-wave half-graph shows ExX/EyX polarization ratio. The lower O-wave half-graph shows EyO/ExO . That’s unity divided by minus the polarization ratio in the upper graph.
Together what are the two half-graphs for X-wave and O-wave telling us? I think they say an E/W-headed X-wave has linear polarization, but X-waves directed at headings more nearly toward a N/S direction parallel to GMF involve more-bulging elliptical polarization. Along the GMF roughly N/S, an X-wave is circular polarized in one rotational sense.
Correspondingly, an E/W-headed O-wave has linear polarization perpendicular to the X-wave and bulges outward from that perpendicular linearity into more-elliptical polarization at other headings nearer a N/S direction. In the N/S direction, the O-wave is circular polarized in the opposite rotational sense versus an N/S-headed X-wave.
The 630m RF electric field in an X-wave or an O-wave varies–with peak amplitudes ranging between Ex and Ey. Meanwhile, that electric field rotates elliptically around and around the direction of propagation as its axis in a clockwise or counterclockwise sense indicated by the plus/minus sign of the ratio.
As mentioned on an earlier day, more than the illustrated O-wave or X-wave from a single ray can arrive at the RX antenna. Especially on single-hop 630m paths, O-wave from one ray may combine in the RX antenna with X-wave from another ray that originated from the same remote TX station.
I’ve had difficulty finding a reference or webpage to compare and doublecheck these 630m theory results. Please e-mail any better wisdom and pointers to references so we can blog them. TU & GL!
*Endnote: See the polarization ratio Rpol formula at page 31 of: http://www.dcjenn.com/EC3630/Ionosphere%28v1.5%29.pdf . You can adapt the polarization ratio Rpol formula to Excel formula format. Make an O-wave spreadsheet column to represent calculations for an angle, say 30°, between ray and GMF. First, compute a column cell F1 giving a value of squared ratio of plasma frequency to operating frequency (475.5KHz), and then in a separate column execute this formula for Rpol :
Do separate columns for each angle you assess beyond 30°. Do corresponding X-wave spreadsheet columns by flipping the sign to plus (+) on SQRT. Then take its reciprocal (1.0 / number) to get calculated numbers to make its Excel line-graph shown as a half-graph for X-wave here. You can instead simply negate the O-wave data, since algebra shows that’s equivalent. I’ve cropped and matched to equalize the scales to make the illustrated X/O graph out of two half-graphs from Excel.”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com)!