Seemingly out of no where a G2 storm manifested and changed the dynamic of the entire session. I don’t think that it was necessarily a bad thing for everyone (unless you live far up North like WE2XPQ!) but it did certainly lead to a very different outcome compared to the previous session. A review of my data from the session suggests that the North / South path was a bit short, although reports were still observed at higher latitudes, only at lower S/N levels. The East / West path, on the other hand, was quite good, with numerous persistent positive S/N reports at or near CW levels with WH2XCR in Hawaii. Its likely that similar observations were not repeated at higher latitudes. In fact, Mark, WA9ETW, reported that aurora was forecast for his area in Wisconsin last night but was obstructed by clouds. Never a good thing for low frequency RF!
Note the textbook peak prior to the dip on the Kyoto DST graph. The same behavior was observed between the 2nd and 3rd of April. Its the peak that often yields very good conditions prior to the bottom falling out and what is often referred to as an onset enhancement. Living in the central US relatively far away from salt water on useful paths, I have historically had to take advantage of these onset enhancements on higher bands like 160-meters in order to make some of the longer-haul contacts. I’ve always considered this to be duct-mode as the electron gradient destabilizes between the E and F layer but I have no real measurements to prove that this same behavior exists on 630-meters.
Before detailing statistics and individual reports for the session I wanted to comment on the recent news article from the ARRL on the topic of 630-meters. There has been some discussion about some of the content in the article and that has led to a number of questions. It was reported that 630-meters was expected to be limited to 1-watts EIRP. This is incorrect. The author has confused 2200-meter and 630-meters. 2200-meters is expected to have a 1-watt EIRP limit. 630-meters is expected to be 5-watts EIRP and the much higher power levels used by Part-5 experimental stations has established that this is not a problem for other co-located services (Reality check: there are none in the continental US). I did like a couple of things said by Fritz Raab, W1FR, the director of the ARRL’s 600-meter research group. In the article, Fritz is quoted as saying that in the future there may be an opportunity to increase power levels on the band and even expand the band from 7-kHz. Its presumed that the latter would be done at the IARU-level since this is a matter of worldwide allocation, which will take time. I also like what Fritz said about future research at 630-meters. Many of us with Part-5 experimental licenses, including the ARRL’s WD2XSH stations, are able to operation in a much larger chunk of spectrum than the 7-kHz prescribed by the IARU amateur allocation. The plan sounds like the ARRL and potentially other Part-5 operators will shift to the spectrum below 472-kHz in order to continue beaconing and studies. Doing so opens up a lot of spectrum for making unhindered two-way contacts under Part-97. This leads to another issue. Historically it has been said that amateurs and experimental stations would coexist in the band but not interact. Do the statements by Raab in the article suggest that this is no longer the case and Part-5 stations will be required to move out of the band? That remains to be seen but since much of the work done by Part-5 stations involves beaconing, this relocation is not a bad idea in my opinion. The WSPR passband is a worldwide amateur allocation so I do not see that shifting. It will likely continue to anchor the center of the band with most CW activity from the middle to the bottom of the band and wider band modes above the WSPR allocation. That’s what I envision but what I think really doesn’t matter. It will all work out.
Now on to statistics and individual reports:
Ken, K5DNL / WG2XXM reports that he decoded seven WSPR stations and was decoded by 34 unique stations. WH2XCR was decoded 17 times at a best of -17 dB S/N.
Phil, VE3CIQ, reports high precipitation static that impacted his session. He decoded three WSPR stations and was decoded by eleven unique stations.
Larry, W7IUV / WH2XGP, reports poor conditions and little high latitude transcontinental path during this session.
Neil, W0YSE/7 / WG2XSV, has recently been doing some very good work improving his station by adding radials. The increase in field strength, and subsequently his reporting, has been significant. This should encourage operators who are seeking station improvements that incremental changes can go a very long way. Neil provided some additional comments and statistics from his tests below:
WSPR activity dominated the session once again but was down somewhat from the previous session with 74 MF WSPR stations observed at 0300z on the WSPRnet activity page.
Regional and continental WSPR breakdowns follow:
There were no trans-Atlantic or trans-African reports during this session. UA0SNV was present but no reports were found in the WSPRnet database.
Eden, ZF1EJ, was alone during this session but provided a number of reports around the US including WH2XCR on the East / West path.
Laurence, KL7L / WE2XPQ, show just how tough it can be to operate from Alaska, particularly when a geomagnetic storm is in progress, increasing absorption. Laurence was able to take advantage of the salt water path to Hawaii, engaging in two-way reports with WH2XCR.
In Hawaii, Merv, K9FD/KH6 / WH2XCR, sees the return of the JA path, with reports from JH3XCU as well as two-way reports with VK3ELV and VK4YB. Merv also received reports from VK2DDI, VK2XGJ, and many stations in the East, including the previously reports WSPR decodes by ZF1EJ in addition to WI2XBV in Florida, KU4XR in Tennessee, and WG2XJM in Pennsylvania.
In Australia, Phil, VK3ELV, and Roger, VK4YB, both exchange two-way WSPR reports with WH2XCR. Phil received additional reports from JH3XCU and TNUKJPM.
Jim, W5EST, presents part 2 to his previous discussion on the topic of “SLIDING WINDOW APPROACH TO 2015-2016 TA SEASON”:
“The accompanying illustration shows the raw 630m nightly numbers of spots for the 2015-2016 transatlantic (TA) WSPR season so far. Transmitting and receiving stations have sampled the 630m long path band conditions from night to night.
Recall from this blog April 6: I’m studying a sliding window approach to describe long path seasonality. Step 1 gathers counts of nightly decodes over the season as raw information two ways.
Step 1A created an activity-oriented reception spreadsheet column that counts up every decode of the same TX obtained at different RX stations in the same timeslot and states the entire number of TA decodes for each whole night. Step 1B created a separate propagation-oriented reception spreadsheet column counts just once the occurrence of a decode in each given time slot from a given TX notwithstanding that the same TX slot may be decoded at two or more RX stations simultaneously.
What lessons learned? First, the counting method didn’t make much difference. The propagation oriented reception counts have the same graphical shape as the activity-oriented reception graph. It’s probably a consequence of the modest number of transmitting and receiving stations in UK/EU and the south central and eastern USA. Since the activity-oriented reception counts are less time-consuming to prepare I will probably do just that type of count in the forseeable future.
Second, the human eye does a good job of discerning features in the raw data and its general behavior. I may perform a calculation procedure to generate an additional sliding window graph. But, for today, I think it’s enough to describe the graph of the raw numbers.
What are the results so far?
First, The graph reminds us of the banner TA nights when TA occurred strongly and plentifully.
Second, the autumn TA was stronger than winter TA. This may be due as much to bad winter weather taking a toll on station participation as to propagation. That question calls for a second look. Anyhow, TA has picked up at least temporarily as we’ve moved into spring.
What I didn’t recall was, third, the remarkably periodic monthly distribution of TA banner nights across the season. (By way of exception, 6 weeks in January-February have peaks but they’re less prominent ones than all other months show.) Perhaps there’s a good sun-based explanation based on the 27 day period of apparent rotation of the sunspots on the sun as seen from Earth. https://en.wikipedia.org/wiki/Solar_rotation
While a solar explanation is appealing, it remains to be seen whether a 27 day period indeed matches the TA dates in the whole season. Can an astro/geophysical cause-and-effect explanation based on sun features credibly support this 630m behavior?
Other explanations I’m leaving aside for the time being. Sculpturing of the distribution by storms would probably not produce the clock-like monthly repetition of tall peaks that the graph shows. Moreover, station operators are not calendaring their operations to activate around the beginning of each month. I studied the question of moon phases in 2014 and posted less than conclusive results on the 600mrg reflector. A lunar cycle explanation seems doubtful.
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD <at> gmail dot (com)!