“Our 630M propagation reminds me of Churchill’s remark about Russia- ‘a riddle wrapped in a mystery inside an enigma.'” – Doug, K4LY / WH2XZO
630-meters never ceases to amaze. Just days ago band conditions seemed a little grim. Springtime storm noise was polluting the band and hearing only a couple of stations was becoming commonplace. While band conditions and propagation have improved since those grim sessions, last night seemed almost like a long December night.
The geomagnetic field was quiet. The Bz was stable and generally North-pointing. Solar wind returned to low levels, below 400 km/s.
John, WA3ETD / WG2XKA, had what might be a season best, with a trans-Atlantic report for DK7FC, two-way transcontinental reports with WG2XSV and WH2XCR, 58 unique exchanges, and first time for the season spots from AC0ZL.
Neil, W0YSE/7 / WG2XSV, had a very strong session that started with a very hopeful waterfall at bedtime.
Neil also indicates that he was reported very early by Eric, NO3M / WG2XJM, and Ken, SWL/EN61 in Indiana. This was also the first time this year to report and be reported by John, WA3ETD / WG2XKA. Neil provided the following additional comments and statistics:
Neil also provided his map for the session, which was very wide ranging for 1-Watt ERP. As I have indicated in the past, one can do a lot with very little on this band if a few variables are controlled.
Doug, K4LY / WH2XZO, decoded DK7FC and has additional comments about this session:
Ken, SWL/EN61, in Indiana provided a number of all-time best statistics for his station, including decodes of 14-unique stations:
Mike, WA3TTS, had a very strong session and provided the following extensive comments and statistics:
WSPR activity was high again, with 72 MF WSPR stations observed around 0200z on the WSPRnet activity page. Regional and continental WSPR breakdowns follow:
There were no reports from the trans-African path. UA0SNV and W6SJP/BY were present during the session but no reports were found in the WSPR database for either station.
DK7FC had a very good session with reports from WG2XKA, WH2XZO, WE2XGR, and WE2XGR/3 on the trans-Atlantic path:
Eden, ZF1EJ, and Roger, ZF1RC, experience identical nights, reporting a number of stations across the US.
Laurence, KL7L / WE2XPQ, operated as WE2XPQ for transmit and WE2XPQ/1 for receive during this session and reported Ken, K5DNL / WG2XXM for the first time in quite a while.
Merv, K9FD/KH6 / WH2XCR, had strong reports from the mainland US, including two-way reports with WG2XKA in Vermont and VK4YB. The path to JA continues to be cut off at the moment.
Phil, VK3ELV, received the following reports from Japan and Hawaii:
Additional statistics, comments, anecdotes, and information:
Phil, VE3CIQ, reports that he decoded ten stations and was decoded by 21 at 50 mW ERP.
Ken, K5DNL / WG2XXM, reports that he decoded 12 and was decoded by 43-unique stations.
John, WA3ETD / WG2XKA, reports that he has a digital oscilloscope for sale which came from an estate. The sale notice can be found here. Please contact him directly for information. This scope would be good for scope match and the price is right.
Jim, W5EST, provided the follow discussion, entitled “PART I: 630M DAYTIME PROPAGATION USING 2/25/16 WORK PLAN”:
“The KB5NJD blog is a regular source of 630m daytime info since Oct. 25. WG2XIQ (Texas) has run one of the very few 630m transmitters on which a lot of the daytime sky wave reception information was based since Oct. 25. WG2XKA (VT) and WH2XGP (WA) likewise have provided daytime 630m transmissions.
So, TABLE I shows daytime skywave receptions starting late October instead of my work-planned start date of Aug. 1. Appended Q&A with John WG2XIQ give some assurance that the daytime info since Oct. 25 is adequately trustworthy.
However, thunderstorms near 630m receivers could mask 630m daytime reception some days, regardless of space weather. Likewise, a station might turn off its 630m transmitter due to a nearby thunderstorm. Here at W5EST I have logged thunderstorms by region daily. Accordingly, thunderstorm tabulation by region of the 630m TX and RX stations in Eastern USA, Mid-USA, West USA is added to the work plan for attention another day.
44 daytime sky wave receptions significantly clustered by dates and accounted for 36% of the 123 days Oct. 25-Feb. 25 (four months).
TABLE I: DATE INTERVALS OF 630M DAYTIME RECEPTION, & DESCRIPTION
Oct. 25. Singleton. October had 1 day of daytime prop we know of.
Nov. 2-6, 9-15, 18-20, 22-25 4 Clusters occupy 19 days of Nov. November had 20 days.
Nov. 30, Dec. 2, 8, 10-12, 17. Scattered, 1 Cluster. December had 9 days of daytime prop.
Dec. 29–Jan.3, Jan 5–12. 2 Clusters January had 13 days of daytime prop.
Jan. 20 & 30. Feb. 6. Scattered. February has 1 day of daytime prop so far.
I’ve now assembled solar flare information from GOES-15 data from the Lebedev web site to compare with our 630m daytime skywave reception information. In Part 2 this Monday, let’s address the question whether or how well solar flares can predict 630m daytime prop by filling in TABLE 2.
The data will tell us the False Negatives Rate and the Precision of various predictors based on solar flare levels. Recall that a False Negatives Rate is the number of daytime prop days incorrectly predicted negative and then divided by all daytime prop days. Precision is the number of daytime prop days correctly predicted positive, divided by all the days the predictor predicted positive.
In the meantime, today let’s get acquainted with a simple “November” predictor that just says, “If it’s the month of November, predict every day to be a daytime prop day.” The 67% precision is favorable because 630m daytime prop occurred 20 out of 30 November days. So far, so good.
However, the 55% False Negatives Rate tells us that if 630m stations relied on the “November” predictor, they would miss the majority of the daytime prop opportunities during the four-months Oct 25-.Feb. 25. So, the “November” predictor is inadequate I think. Moreover, I don’t trust a calendar-month predictor from year to year since 630m daytime prop might unexpectedly concentrate into some other month in other years.
See you Monday!”
Additions, corrections, clarifications, etc? Send me a message on the Contact page or directly to KB5NJD <at> gmail dot (com)!