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The K7RA Solar Update

07/10/2010

The average daily sunspot numbers for this week rose from 11.7 to 16, back to the level from two weeks ago. The geomagnetic indices have quieted down, with average mid-latitude A index dropping over five points from the previous week. Sunspot numbers for July 1-7 were 11, 11, 11, 11, 23, 23 and 22, with a mean of 16. The 10.7 cm flux was 73, 73.4, 72.4, 71.6, 72.7, 72.7 and 74.1, with a mean of 72.8. The estimated planetary A indices were 12, 9, 7, 5, 5, 3 and 3, with a mean of 6.3. The estimated mid-latitude A indices were 8, 8, 6, 5, 2, 1 and 2, with a mean of 4.6.

Sunspot group 1084 has continued to dominate. It first appeared on June 27 and has continued for 12 days. For June 27-July 8, the relative size of the sunspot group (in millionths of a solar hemisphere) was 90, 90, 100, 110, 110, 100, 150, 110, 100, 110, 100 and 50. In addition, there was a single day appearance of sunspot group 1085 on June 29 with a relative size of 10, and group 1086 made a three day appearance with a relative size of 10 on July 5-7. Just as sunspot group 1084 fades, it looks like old group 1082 is making a reappearance. It last was on this side of our Sun on June 17-25 and it is now visible over the eastern limb.

The latest NOAA/USAF forecast shows a rising solar flux for July 9-15 of 76, 78, 78, 78, 80, 80 and 78, accompanied by low planetary A index for the same period of 6, 5, 5, 5, 8, 12 and 8. Geophysical Institute Prague predicts quiet to unsettled conditions July 9-10, quiet July 11-12 and unsettled July 13-15.

Jeff Hartley, N8II, of Shepherdstown, West Virginia, reports that on Friday, July 2 around 2300, 6 meters was open to 9Y4VU (Trinidad and Tobago), CO8LY (Cuba), FG5FR (Guadeloupe) and a TI5 (Costa Rica) station. Jeff also sent an update for the weekend: “I spent a lot of time on the radio over the holiday weekend. Conditions were spectacular for multi-hop sporadic-E at times. The evening of the 2nd, your area in Northwest Washington was in the bull’s eye for double hop Es on 6 meters. Signals from the Seattle area were actually over S9 from several stations, but no VE7s heard. Also, Southern California and Arizona were in for long stretches. A few stations were worked scattered around the Rockies in Nevada, Utah and Idaho, as well as New Mexico. I worked five new grids, all double hop except for K7RE in South Dakota.

“Saturday morning July 3, I was awake early and found a couple of EU on 15 meters, so I tried a CQ on 28400 SSB and was immediately answered by DO6AN at 1149. Between then and 1254, I worked a bunch of Europeans. I was tuning 6 meters off and on during my run on 10 to no avail and finally found F6KHM calling CQ. I then worked GJ4FDM on the first call for a new country, and then ON4GG. By the time breakfast was over 20 minutes, later both 6 and 10 meters were closed to Europe. Six meters was open to W0, W5 and sometimes Florida most of day until 2100.

“On Monday the 5th, I heard a beacon from Europe, as well as several from Seattle and VE7 very loud at 6 AM PDT on 10 meters. I called a couple of CQs toward Europe with no luck, tuned and found a loud F8KHF running a big station then CQed again on 28455. Between 1305-1404, and again 1450-1515 -- the band never closed in between -- I worked even more Europeans. The band was still open well to England when I finally stopped. Quite a few new ops missed an opportunity to work new countries on 10 meters; the USA activity was surprisingly low. Be alert for beacons and don’t be afraid to call CQ. I also heard the EA4Q beacon Sunday afternoon, but couldn’t raise anyone on CQs.”

Rod Vorndam, K9ROD, of Rye, Colorado, lives at 7000 feet elevation in a rare grid square. He writes: “Seems like there is a lot more 6 meter activity during the day this year. When I worked 6 meters a few years ago, most of the activity was in the evening hours. I loved working a pile up on July 1 in the evening hours (54 contacts in 90 minutes). I live in DM77 which is #40 on the rare list (many thanks to the people that did the Fish Memorial Study to determine grid square rarity). I can’t image not living in a rare grid square. I’m looking forward to 6 meters getting even better!”

I believe the Fish Memorial Study refers to Fred Fish, and a report on rare grid squares is here.

Peter Laws, N5UWY, of Norman, Oklahoma, wrote about odd, short path propagation during Field Day on 10 and 15 meters: “From N5UWY, I worked K5PXP on 10 meters, 375 km (233 miles) to my east. More surprisingly, to me at least, I worked W5MRC on 15 meters, a mere 226 km (140 miles) to my south. A few minutes later and a few kilohertz up, I worked N3IC at 1869 km (1161 miles). All contacts were all around 0330 on June 27. I don’t think I’ve ever made a contact that short (375 km) on 15, save for a few contacts in my own county.”

John Tudenham, W0JRP, of Joplin, Missouri, mentioned more short skip on 15 meters during Field Day. He wrote, “You didn’t mention about the good E-skip on 15 meters on Field Day. I worked mostly 15 meters CW from the Joplin Amateur Radio Club’s Field Day station, W0IN, and made more than 60 contacts on CW on 15 and about 20 on 15 SSB. The E-skip was as close as Illinois, Kentucky, Tennessee and North Texas; these were good signals. I also worked on F2 two stations in Hawaii and one Virgin Islands, running 100 W to a homebrew ground mounted vertical, as well as a few contacts on 10 and 6, loading 15 meter antenna.”

Also from Missouri, Kent Doucey, N0IRM, of Galena, Missouri, reports “I wanted to drop you a line about the nice band openings here in Southwest Missouri on July 4. Early in the day, around 1300-1400, great contacts were made on 20 meters to South Korean stations DS5FNE, HL5NLQ and HL4CBX with solid 57 signals. We also had a nice contact with V85RY from Brunei, made at the same time with a fair 54 signal. Signals seemed to be solid with little fade on a very quiet band. It was nice to see these stations since the conditions have been poor for the past bit. Then on the afternoon of July 4 at around 2100-2200, we made contacts with HA4FF, 4O3A, IK4GRO, CT1DVV and F5BZB on 10 meters! Signals ranged from 53 to 57 with fading signals into Southwest Missouri, but were all workable. It was nice to see 10 meters open to Europe again.”

All times listed are UTC, unless otherwise noted.

Amateur solar observer Tad Cook, K7RA, of Seattle, Washington, provides this weekly report on solar conditions and propagation. This report also is available via W1AW every Friday, and an abbreviated version appears each Thursday in The ARRL Letter. You can find a guide to articles and programs concerning propagation here. Check here for a detailed explanation of the numbers used in this bulletin. An archive of past propagation bulletins can be found here. You can find monthly propagation charts between four USA regions and 12 overseas locations here. Readers may contact the author via e-mail.



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