Overnight yielded the lowest WSPR spot count I can remember but it was very noisy as the evening progressed as several storm systems remained active include a very noisy cluster of storms drifting South from Kansas into Oklahoma. Propagation was, in fact, good as transcontinental reports between WH2XGP and WG2XKA were registered and a nice surprised from David, VK2DDI, as he reported my signal at 0920z and 1000z. When the path is open, which was foreshadowed by recent reports of WG2XXM in VK, David seems to be able to hear me but it has been a while since his last report for my station. I am convinced that this is a seasonal propagation event where the noise on the receive end has the be “just right”. Its almost like we are playing shuffle board, trying to get as close to the line as possible that represents the Summer Solstice (on Monday!) in North America. Let’s see if these paths continue. Summer always yields interesting propagation that many would say should not happen. The good news is that after Monday, the days begin to get shorter in the northern hemisphere.
Geomagnetic conditions represent more of the same. Conditions are quiet with a North-pointing Bz that offers the geomagnetic field protection from the high speed solar wind stream that has persisted above 600 km/s for some time now.
Larry, W7IUV / WH2XGP, reports that he decoded eight WSPR stations and was decoded by 23 unique stations in a session that seemed very similar to Winter time conditions aside from the large number of active VE stations, particularly in the Pacific Northwest. We have seen activity like this before and its bizarre because there can be a lull through the Spring and then the number of participating stations spikes through much of the Summer into the new season starting on September 1. I guess everyone gets their antenna work completed and they have gone on vacation and are now just trying to stay inside where its cool for the hottest part of the Summer.
John, VE7BDQ, reports that he was transmitting WSPR for four hours, yielding nine decodes from WH2XCR, W0YSE/7, VE7SL, VA5LF, VE7KPB, WG2XSV, VE7IGH, WH2XGP, and VE7CNF. John decoded five stations including 26XSH, VE7SL, VE7CNF, WG2XSV, and WH2XGP.
John, WA3ETD / WG2XKA, was QRV in spite of surprise storms in VT:
Joe, VO1NA, reported that he would be QRV with QRSS10 on 477.7 kHz during the overnight period. Roelof, PA0RDT, received his signal and provided the following report with screen captures found here.
Steve, VE7SL, reports that he decoded eight WSPR stations and was decoded by nine unique stations during the session and notes that he could have benefited from more power.
Ken, SWL/EN61, in Indiana has been testing loop sticks recently and offers the following results:
I’m a big fan of the loop stick and have seen them work extremely well with extremely narrow laser-like beams on receive. Its my plan to put one high on a rotator this Summer once a few other projects are out of the way for point-to-point operating this Winter.
Rick, W7RNB / WI2XJQ, was asked by Larry, W7IUV / WH2XGP, in the ON4KST chat/logger about his antenna system. Rick reports a 30-foot tall vertical with a 10-foot capacity hat and an estimated 170 mW ERP from 100-watts TPO. Rick made some improvement during the session which boosted his signal into British Columbia. Rick is using a JUMA to generate a signal.
Neil, W0YSE/7 / WG2XSV, reports a very strong night, particularly with Canadian stations:
Regional and continental WSPR breakdowns follow:
There were no reports from the trans-African, or trans-Equitorial paths during the session.
In the Caribbean, Eden, ZF1EJ, reported WG2XXM and WG2XIQ during the session. It is still pretty noisy in the Caribbean due to storms in the Gulf of Mexico, southeastern US and the Atlantic:
Laurence, KL7L / WE2XPQ, reported WH2XCR, VE7SL, and WH2XGP:
Merv, K9FD/KH6 / WH2XCR, had another strong night with the usual suspects in North America and Australia in addition to VK2EIK, which is reporting Merv for the first time and returning reports from VK3GJZ who has his first report of Merv this past week. Two-way reports continue with VK4YB and VK3ELV and VK2XGJ and VK2DDI continue to hear very well.
Jim, W5EST, presents “WG2XXM-VK2DDI/VK2XGJ ACHIEVED JUNE 16, 2016, NEAR VK WINTER SOLSTICE”:
“XXM’s -22dB peak WSPR SNR June 16 was decoded by VK2XGJ at 1114z—coinciding with XXM’s 1113z sunrise (SR). Four out of the seven XXM-VK decodes, including VK2DDI’s peak decode of XXM -25dB, happened within +/-7 minutes of XXM SR. Two more XXM-vk2ddi decodes happened about 40 minutes prior to XXM SR.
The OK-VK path itself was unusually favorable—as indicated by the XXM-vk2xgj 0946z -31dB spot 1.5 hours before SR. Moreover, a sunrise enhancement was in progress near XXM in Oklahoma, recognizing that 9dB higher SNR peak -22dB 1114z.
Here’s the three-part XXM-VK sequence that made the long trip to SE Australia:
2016-06-16 09:46 WG2XXM 0.475710 -31 0 EM15lj +37 5.012 VK2XGJ QF55jl 13962 8676 46 minute gap
2016-06-16 10:32 WG2XXM 0.475711 -31 0 EM15lj +37 5.012 VK2DDI QF55hf 13987 8691
2016-06-16 10:36 WG2XXM 0.475711 -26 0 EM15lj +37 5.012 VK2DDI QF55hf 13987 8691 42 minute gap
2016-06-16 11:08 WG2XXM 0.475710 -30 0 EM15lj +37 5.012 VK2XGJ QF55jl 13962 8676
2016-06-16 11:14 WG2XXM 0.475710 -22 0 EM15lj +37 5.012 VK2XGJ QF55jl 13962 8676 SR Enhancement peak!
2016-06-16 11:20 WG2XXM 0.475711 -25 0 EM15lj +37 5.012 VK2DDI QF55hf 13987 8691
2016-06-16 11:20 WG2XXM 0.475710 -26 0 EM15lj +37 5.012 VK2XGJ QF55jl 13962 8676 12 minute 3rd part ends.
Meanwhile, XXM-xcr into Hawaii was hitting a one-month high SNR -14dB 1052z and stayed in the teens at Merv’s place until XXM’s Oklahoma SR clipped off XCR reception 1114z:
2016-06-16 10:22 WG2XXM 0.475712 -20 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 10:28 WG2XXM 0.475712 -17 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 10:32 WG2XXM 0.475712 -29 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 10:36 WG2XXM 0.475712 -20 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 10:40 WG2XXM 0.475712 -18 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 10:44 WG2XXM 0.475712 -22 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733 miss 1048z
2016-06-16 10:52 WG2XXM 0.475712 -14 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733 2 misses 1058, 1102z
2016-06-16 11:08 WG2XXM 0.475712 -17 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733
2016-06-16 11:14 WG2XXM 0.475712 -16 0 EM15lj +37 5.012 WH2XCR BL11je 6007 3733 ended at XXM SR
A sunrise enhancement or “bump” is any prominent SNR peak that occurs around sunrise. Additionally, I visualize it as any arrangement of sunrise terminator-induced non-planar ionospheric contours that concentrate RF signal rays in a prominently SNR-enhancing way.
To obtain the 4 decodes 1108-1120z, XXM was transmitting WSW to VK within mere degrees above the horizon into the SR enhancement as much as 5 minutes before and 7 minutes after XXM sunrise. At XXM’s latitude the terminator moves west at a speed of 22 km/minute. Relative to XXM, the terminator position during that interval ranged roughly 110km east to 160km west of XXM’s QTH. [ = earth circumf. 40,075km cos(35.5°N.LatitudeOK) x (5 or 7min)/(1440min/day).]
A 5° guesstimated signal ray elevation would intersect a 120km-high E-layer about 1370km downrange. [ (120km) cotan 5°.] That means a sunrise enhancement due to some physical deformation of the ionosphere would extend as much as 800 miles southwest of the terminator, if my conception of it is correct. On the way to the E-layer, the XXM signal would reach a 75km-high D-layer 857km downrange and well beyond the 160km-west terminator position 7 minutes after SR.
If an SNR-enhancing deformation extends west from the terminator, which seems likely if the terminator is responsible for it, then there could be at least about 60 minutes duration of such deformation from it first appearing overhead XXM until it reached 1371km west of XXM going 22km/minute. Whether that’s physically possible in view of whatever speed of sound in the ionosphere and possibly-applicable westward ionospheric wind velocity, I’ll leave aside for now.
I suggest that a sunrise enhancement happening even as early as about 45 minutes before SR seems plausible. Also plausible is XXM transmitting at a 5° low angle in daylight 7 minutes after SR through an as-yet pre-SR D-layer to successfully reach a conveniently-deformed E-layer higher up and get enhanced and started on its way to Australia.
Now let’s turn to another aspect of this June 16 trans-Pacific achievement. Was there something significant about the near-solstice orientation of XXM’s SR terminator? Sun rose in Oklahoma from 60° NE heading or 30° N. of E. That sunrise heading would favor a SW launch azimuth 240° from XXM. The actual launch angle from XXM to VK2XGJ on the WSPR database was not too different: 250° (and 272° to XCR). Given the likelihood of a sunrise enhancement at XXM, the orientation of the XXM SR terminator seems a not-unlikely contributor to this OK-VK event.
What does this XXM-VK event mean to 630m in any larger sense? Perhaps it could have occurred last year or year before. But it didn’t, as far as I know. Persistence pays, of course, that’s one message. Furthermore, I think going forward we should be alert for a possible trend to better N. America-VK propagation this fall and winter than we have seen in the last two years. (See April 9, this blog, for a trans-Pacific graphical illustration.)
Has this N. America-VK achievement ever occurred at either 2200m or 630mthis time of year in the past at amateur power level? Actually, yes on LF, but not 630m as far as I’m advised.
During a 2001 trans-Pacific test organized by Bob ZL2CA, Steve VE7SL was able to claim Argo reception around sunrise June 30, 2001, of ZL6QH, Wellington NZ, 11,709km. ZL6QH ran 100W into a longwire with dual-frequency CW two-minute dits/dahs [JH note: QRSS120]. http://www.arrl.org/w1aw-bulletins-archive/ARLB026/2001
Laurence WE2XPQ says 137KHz 2004-2005 succeeded from his then-Oklahoma QTH to ZL in Oct thru July from QRV to stn QRT – except June because ZL wasn’t listening then. Time of night was typically around 10Z but successes from 08-11Z were seen. Interesting: That was roughly 11 years ago—sunspot cycle effect vis a vis 2016? XPQ went QRT from OK, and I don’t have any other info for intervening years 2005-2013.
Did lunar phase have anything to do with the XXM-VK event? The waxing moon is 92% of full, yes. But the lunar idea has not been very satisfactory in the past, and I set that idea aside for now.
Why didn’t XXM get any decodes in VK-land the following day, June 17? The lightning locator WWLLN site indicates that modest storm cells were active in S. Queensland and off the east coast of Australia. That probably increased the band noise too much, considering the mostly low SNRs involved.
Why didn’t WH2XGP decode into VK when XXM did it June 16? The XGP peak SNR, -18dB of XGP into XCR June 16, was far below the -11 level that I have usually associated with XGP-VK success in earlier equinox-related mini-seasons. Something about the XXM-VK path surpassed the XGP path to VK propagation-wise.
The long-path discussions May 13 and 14, this blog, may offer some ideas.
XXM reached VK2XGJ -29dB 4/15/16 1042z once when XGP enjoyed multiple decodes there. XXM reached VK4YB and VK2DDI once each 4/9/16 when XGP narrowly made it once to VK2XGJ. Both XGP and XXM made it to VK4YB 4/2/16. XXM tickled the decoders at VK4YB, VK2DDI, and VK2XGJ several times 4/3/16 and reached -22dB once at VK2DDI. 4/1/16, 9/18/15 and 8/18/15 are XXM days, etc, in this vein as well.
Why didn’t VK3ELV receive XXM? In the VK3ELV receptions for June 16, a gap as to even local VK’s between 1002z and 1514z probably blanked the XXM opportunity there.
Why didn’t VK4YB, who was receiving all during the XXM success June 16, receive XXM? Indeed, Hawaii XCR-vk4yb peaked -15dB SNR at 1102z that night. XCR-vk2ddi/xgj reached -21/-22dB 1136/1126z. Evidently, spotlight propagation was favoring Sydney compared to Brisbane.
Probably the cause of the spotlighting originated far from Oklahoma and either near the equator or near the path end at SE Australia. I say this because XCR had unusually good receptions of XXM on June 16 as listed earlier above. Hawaii’s XCR lies far off the XXM-VK path, while excellent SNRs due to XXM were nevertheless enjoyed at XCR. That geographically-wide effect is inconsistent with the idea that SR enhancement near XXM would be a cause of spotlighting in a small part of Australia.
If you have more wisdom or more information you can provide, do let us know. GL!”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD gmail dot (com)!