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 Previous: W1AW, K1D, AO-51, to be On the Air for Kid's Day(s) |  Next: Surfin': Weird Gear from the Past |
SEATTLE, WA, Jun 10, 2005--Sunspot and solar flux readings were up this week, while geomagnetic K and A indexes were down a bit--which is generally what HF operators want. There were no big events triggering geomagnetic storms this week, as indicated by the low A index numbers. A solar windstream last weekend only drove geomagnetic indices up to moderately active levels. But two big new sunspots--775 and 776--are rotating to the most effective position for affecting Earth. Solar flux for this weekend, June 10-12 is expected to be in the vicinity of 110 to 115. Geomagnetic conditions should be quiet, although the new sunspots are magnetically complex and could hold a surprise.
We're now moving toward summer propagation. Summer solstice in the Northern Hemisphere will occur June 21 at 0646 UTC. Today we are 80 days past the equinox, and the bands are behaving differently than they were a few months ago. For instance, paths from the continental US to South America are open much later on 17 and 20 meters. You can run two instances of W6ELprop and make some tests. For instance, run a test from the center of the Continental US (by entering W for the prefix) to Brazil for any date this week, and enter an average of several days of sunspot numbers (from the end of this bulletin).
You can do the same for a date in late March, and get the numbers from past bulletins. Even though average sunspot numbers were lower in late March than they've been this week, propagation possibilities to Brazil during midday on 10, 12 and 15 meters in March were much better than they are now. But signals over the same path show better current openings much later into the evening on those same bands than they were in late March. Plot from the central US to Hawaii as the target, and 20 meter signals drop out in the evening in March but are currently strong all night long.
This weekend, June 11-13, is the ARRL June VHF QSO Party. The object is to get as many contacts in as many grid squares as possible. Many transceivers these days have 6-meter capability, so it isn't much of a stretch for HF operators lacking a 6 meter antenna to just toss up a dipole at the last minute. A half-wave dipole is only about 9 feet, 3 inches long on 6, and when the band opens up, a simple antenna can do quite well.
If you don't know your grid-square, there's a calculator on the ARRL Web site. If you hear stations reporting unfamiliar grid squares--at least for the United States there is a good map on the Icom Web site. The rules for the contest are on ARRL Web site.
There have been many nice 6-meter openings recently, mostly via the sporadic-E layer skip common this time of year. Frank Fascione, KB1LKB, of Manchester, Connecticut, sent in a report for Sunday, June 5. He reports an all-day opening on 6 meters to the Caribbean as well as to Georgia, Florida and Alabama. Among stations heard but not worked were FG5FR, FM5JC, FM5AD, 9Y4AT, YU4DDK, and PZ5RA. Frank contacted several new ones, including FJ5DX, YV4DYJ, PJ2BVU, HK4SAN and J69EN.
Doug, CO8DM uses 100 W to a 2-element quad at 65 feet on 6 meters. He reports that around the first of the month he copied European stations, including Italy and Sicily and (on CW) Malta. The next morning he heard M0BJL in the UK.
Eric Hall, K9GY urged: "Please mention for people to get on with their radios that can work VHF and be active in the ARRL VHF contest. It doesn't take a lot of stuff to make QSOs!" Eric made his first 6 meter QSO on June 5 with an FT-817 and a 6 meter HamStick mobile antenna. He was in FM18, and he worked N4OX in EM60 on 50.13 MHz SSB. Then he worked KA4DPF in EM81 about 20 minutes later.
Bill VanAlstyne, W5WVO, in DM65 seemed almost giddy about the opening on Tuesday, May 31. He says it was "one of the most incredible 6 meter Es openings I've ever been part of since moving to New Mexico a few years ago." He says the band was open from before 7 AM local time and--with the exception of a couple of hours around midday--stayed open until nearly midnight. I think we're all still catching our collective breath from this one!" he said.
Bill runs 100 W to an 18 foot 5-element Yagi up 25 feet. He made more 75 contacts and worked 13 new grids to boost his total above 300. He says he "ran pileups of calling stations for an hour at a time like I was a DX station." During his hottest stretches, he says, even QRP signals exceeded S9 +20 dB and were coming in from all over the country at the same time. Path lengths ranged from quite short (450 miles) to quite long (1800 miles). No so-called "double hop" here. East Coast signals were as strong as those coming from half or a quarter of the distance away, he said. "There were obviously a number of rather interesting propagation modalities going on here," he said. "If only we really understood this stuff!"
A ham since 1962, Bill says he don't think there's anything more exciting than this kind of Es opening on 6 meters. "It's almost a transcendent experience!" he said.
Nice to hear such enthusiasm. Maybe that's why 6 meter enthusiasts call it "The Magic Band."
We're now two weeks away from ARRL Field Day. The long-range forecast from the US Air Force shows a planetary A index of 20 (a bit high) for both Saturday and Sunday of Field Day weekend, June 25-26. This is probably predicted because of coronal holes and solar wind from the most recent rotation of the sun. Two weeks is a long way off for predicting conditions, so we'll try to come up with a more meaningful look in a couple of weeks.
For more information concerning radio propagation and an explanation of the numbers used in this bulletin see the ARRL Technical Information Service Propagation page. An archive of past bulletins is available on this Web site.
Sunspot numbers for June 2 through 8 were 69, 55, 74, 77, 89, 94 and 100, with a mean of 79.7. 10.7 cm flux was 93.3, 95.3, 96.9, 105.4, 106, 109.1 and 115.7, with a mean of 103.1. Estimated planetary A indices were 7, 8, 18, 20, 13, 18 and 6, with a mean of 12.9. Estimated mid-latitude A indices were 7, 10, 12, 14, 7, 11 and 3, with a mean of 9.1.
Amateur solar observer Tad Cook, K7RA, 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 in The ARRL Letter. Readers may contact
the author via e-mail.
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