No sunspots have appeared since June 26. If we use predicted solar flux as a proxy, flux is expected to be less than 70 until July 8, this Sunday, so I would not expect sunspot activity to resume perhaps until July 13-23 when solar flux is expected to rise above 70.
Predicted solar flux is 68 on July 6-7, 70 on July 8-12, 72 on July 13, 75 on July 14-15, 77 on July 16, 80 on July 17-19, 77 on July 20-21, 73 and 71 on July 22-23, 70 on July 24-25, 69 on July 26-27, 68 on July 28 through August 5, 69 on August 6, 72 on August 7-9, 75 on August 10-11, 77 on August 12, 80 on August 13-15, 77 on August 16-17, then 73 and 71 on August 18-19.
Predicted planetary A index is 10 on July 6, 5 on July 7-14, then 15 on July 15, 5 on July 16-19, then 15, 8, 10, 18 and 7 on July 20-24, 5 on July 25-28, 8 on July 29, 5 on July 30 through August 10, 15 on August 11, 5 on August 12-15, then 15, 8, 10 and 18 on August 16-19.
Chip Margelli, K7JA, had a comment on the coverage of Field Day conditions last week: “I saw your propagation report re Field Day. I’m still trying to figure out which planet that represented.
“Conditions on Field Day were generally awful. The K index rising to 4 Saturday morning really tore up the bands and blew out the E layer here in the western US. Neither 6 nor 10 meters opened at all on Saturday, and there were only a few pop-up paths that emerged on Sunday on meters. On six, while much of the eastern part of the country had a big band, but in southern California we worked five whole stations in South Dakota. That was it.
“Twenty meters was fair at best, but it closed early Saturday night. Fifteen was a huge bust, and 40 was very disturbed, with heavy fading and East Coast signals generally huddling right at the edge of being audible. Forty meters never really took off to the east, causing our station to be at least 30% down from our anticipated numbers.
“It wasn’t a good weekend for propagation at all. It was especially disappointing because 6 meters had been wide open all week before Field Day, and a week after the event it was open across the country again.”
For more information concerning radio propagation, see the ARRL Technical Information Service at http://arrl.org/propagation-of-rf-signals. For an explanation of numbers used in this bulletin, see http://arrl.org/the-sun-the-earth-the-ionosphere.
An archive of past propagation bulletins is at http://arrl.org/w1aw-bulletins-archive-propagation. More good information and tutorials on propagation are at http://k9la.us/.
Monthly propagation charts between four USA regions and twelve overseas locations are at http://arrl.org/propagation.
Instructions for starting or ending email distribution of ARRL bulletins are at http://arrl.org/bulletins.
Sunspot numbers for June 28 to July 4, 2018 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 69.5, 68.6, 68.8, 68.1, 66.6, 68.2, and 67.9, with a mean of 68.2. Estimated planetary A indices were 5, 4, 4, 3, 3, 4, and 5, with a mean of 4. Estimated mid-latitude A indices were 5, 3, 3, 4, 4, 5, and 4, with a mean of 4.
Full 20m, 15m and 10m Band Coverage (with Feed Point Mounted ATU) Under 8 Feet Tall! No Radials! Force 12’s Sigma Series Verticals are contest a... Read more
VERTICAL ANTENNA Highly efficient end loading 1/2 Wave vertical covers bands: 40, 30, 20, 17, 15, 12, 10, 6 and 2 Meters. Requires no radials,... Read more
Check out this YouTube clip that Ulf SM3RAB made A/Bing the K1N DXpedition on a Magnum 340 full-size 3 element Yagi that uses the G0KSC OP-DES feed sy... Read more
In order to support the proliferation of third party app stores worldwide, we have now released RFinder on Android as trialware! Just go download it f... Read more
Regarding access by the Aeronautical Mobile Service to the amateur radio 144 MHz band Switzerland’s Ofcom says: ‘a possible so-called co-p... Read more
The IEEE Microwave Theory and Techniques Society (MTT-S) has announced the MTT-Sat Challenge for groups of students developing RF hardware for CubeSat... Read more
ARRL member-volunteers will be part of the excitement as the 2019 International Experimental Aircraft Association annual AirVenture show gets under wa... Read more
Online registration is now available for Microwave Update 2019. Sponsored by the North Texas Microwave Society, the event will take place October 3 –... Read more
The Netherlands International Amateur Radio Union (IARU) member-society VERON reports a “disappointing response” from national regulator Agentschap Te... Read more
Thousands of Scouts from some 160 countries who will attend the 24th World Scout Jamboree this summer in West Virginia will have the chance to witness... Read more
High school students in Brazil are building a ground station for the amateur radio transponder on the QO-100 geostationary satellite as part of a STEM... Read more
The Netherlands communications regulator, Agentschap Telecom (AT), has given a disappointing response to the call by Dutch radio amateurs for the 144-... Read more