Propagation Forecast Bulletin #45 de K7RA:

ZCZC AP45
QST de W1AW
Propagation Forecast Bulletin 45 ARLP045
>From Tad Cook, K7RA
Seattle, WA November 6, 2009
To all radio amateurs

SB PROP ARL ARLP045
ARLP045 Propagation de K7RA

Thanks so much to Steve Nichols, G0KYA for writing the Propagation Forecast Bulletin last week. See his blog at, http://g0kya.blogspot.com/.

In addition to the sunspot group 1029, which graced us from October 23-30, a new one (1030) just emerged on Thursday. It is currently in a maximally geo-effective position (in other words, in the center longitudinal meridian as viewed from earth), and may provide some enhancement for the ARRL CW Sweepstakes Contest this weekend. On Thursday the daily sunspot number was 15. Of course, this is a new Cycle 24 spot.

Geomagnetic indices continue to stay very quiet. Checking numbers at http://www.swpc.noaa.gov/ftpdir/indices/DGD.txt you can see that the planetary K index and the college K index were a solid 0 for all of November 3-4 and most of November 5. One strange (to me) set of numbers is on November 5, when the K index in all three zones was exactly the same. It was 0 all day, then for one three hour period it was 1, then back to 0 for all three, planetary, college and mid-latitude. The A index is calculated using the K index data, and the A index for that day was 0 at mid-latitude and high latitude, but was 1 for planetary numbers. Why was that?

Expect geomagnetic conditions to remain quiet and stable. NOAA and the US Air Force predict planetary A index at 5 for today, November 6, and 7 for November 7, then back to 5 for November 8-19.

Geophysical Institute Prague predicts quiet to unsettled conditions November 6-7, and quiet conditions November 8-12.

October had some good numbers, with an average daily sunspot number of 7.0. That is the highest level since March 2008. Our three-month moving average showed 4.64 for August through October, centered on September. This was up from 4 centered on both July and August. Three month averages centered on January through September 2009 were 2.19, 2.02, 1.49, 2.01, 4.22, 5.2, 4, 4 and 4.64.

Tom Morton, CX7TT in La Paloma, Rocha, Uruguay sent a message on October 30 concerning the CQ World Wide SSB DX Contest, and his operation on 10 meters. He wrote, "Around 1:00 PM local Saturday, 10 meters opened with a bang and propagation was awesome to EU then later the US. I expected 10 to shut down on Sunday so spent a lot of time Saturday milking the band. Even though I did foray down to 15 meters on both days, I wound up with 1000 QSOs, 93 countries and 22 zones. What a blast!"

Jim Brown, W5ZIT of Farmersville, Texas had a question about propagation that surprised him on 17 meters. Jim wrote, "I thought I would drop you a note concerning an unusual QSO I had on 10/30/09. At 2350 UTC I worked AE5PW in Newport Arkansas on 17 meters using the Olivia mode. Signals were 20 over 9 for a few minutes and then faded down to S5 before we signed. I am located near Farmersville, TX, about 30 miles NE Dallas. This distance was something like 250 miles or less, and I thought this very unusual at the time. I was wondering what type propagation would support this short skip on 17 meters. It would seem to be too short even for sporadic-E. I was using a 550 ft loop up 30 ft at the time."

I took the addresses for W5ZIT and AE5PW from FCC records, and calculated the distance at 297 miles. But note that for an antenna, Jim is using a 550 foot wire strung in a loop, 30 feet above the ground. Perhaps there is some high angle radiation going on, and the change in signal strength was due to some drifting patch of ionosphere above the two stations. This was on the last day of an 8 day run of sunspots.

Jim said he is using Olivia, which is a robust digital mode for HF. See http://www.oliviamode.com and http://hflink.com/olivia for more info.

I thought perhaps the 550 foot figure was a typo, but I checked out Jim's QTH at http://tinyurl.com/yk8d95s (clicked on "Bird's eye," then zoomed in) and saw there is plenty of room to stretch out.

Clay Melrose, WA6LBU of Wellston, Oklahoma and Chuck Kershner, W1EMQ of Clinton, New York were both pleased by long distance contacts on 40 meters on November 1.

W1EMQ worked UU1CC in Crimea on CW at 0050z with good signals using an old 4BTV vertical in wet soil and a Drake TR4. WA6LBU worked ZS3D running 25 watts SSB with a MP-25 manpack military radio into a G5RV at 0600z. ZS3D was using a 40 meter hex beam.

If you would like to make a comment or have a tip for our readers, email the author at, k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL Technical Information Service web page at, http://www.arrl.org/tis/info/propagation.html. For a detailed explanation of the numbers used in this bulletin see, http://www.arrl.org/tis/info/k9la-prop.html. An archive of past propagation bulletins is at http://www.arrl.org/w1aw/prop/.

Monthly propagation charts between four USA regions and twelve overseas locations are at http://www.arrl.org/qst/propcharts/.

Sunspot numbers for October 29 through November 4 were 19, 13, 0, 0, 0, 0, and 0 with a mean of 4.6. 10.7 cm flux was 76.7, 75.2, 75.1, 72.3, 71.4, 71.5, and 71.4 with a mean of 73.4. Estimated planetary A indices were 7, 11, 1, 2, 2, 0 and 0 with a mean of 3.3. Estimated mid-latitude A indices were 5, 8, 1, 2, 2, 1 and 1 with a mean of 2.9.
NNNN
/EX

Source: W1AW Bulletin via the ARRL.

There are no comments on this article: Post One