SB PROP @ ARL $ARLP025 ARLP025 Propagation de K7RA
ZCZC AP26 QST de W1AW Propagation Forecast Bulletin 25 ARLP025 From Tad Cook, K7RA Seattle, WA June 22, 2012 To all radio amateurs SB PROP ARL ARLP025 ARLP025 Propagation de K7RA
Sunspot numbers seemed to be in a free-fall this week. Average daily sunspot numbers declined over 29 points to 87. Average daily solar flux fell 6.2 points to 126.2. (We erred in last week's bulletin when we said the average daily solar flux for the week of June 7-13 was 115.9. It was really 132.4).
The outlook for Field Day weekend, June 22-23, is for low sunspot numbers and quiet geomagnetic conditions. The progression of daily sunspot numbers in the past five days (June 17-21) was 96, 66, 64, 29 and 13.
Predicted daily solar flux is just 95 for June 22-29, 125 on June 30 through July 7, then 130, 135, and 140 on July 8-10, then 145 on July 11-12.
Predicted planetary A index is 5 on June 21-29, then 8 on June 30, 15 on July 1-3, 8 on July 4-5, 5 on July 6-7, 8 on July 8-9, and 5 on July 10-14.
The solar flux forecast improved slightly from June 20-21. On June 20, a flux value of 90 was predicted for June 21-28. Then the next day, June 21, the predicted solar flux was changed to 95, predicted for June 22-29.
The sunspot number at 13 on June 21 was the lowest since August 15, 2011. On the same day the solar flux dropped to 98, the lowest value since April 13, 2012, ten weeks ago today.
OK1MGW sent a geomagnetic forecast for July 22 to July 9, 2012. Mostly quiet, June 22-23, quiet to unsettled, June 24-29, quiet to active June 30, active on July 1-3, quiet to unsettled July 4-7, and quiet to active on July 8-9.
Last week two more solar videos accompanied by dramatic music appeared at
http://www.universetoday.com/95831/sun-spews-earth-directed-flares/.
Also check
http://space.brevardtimes.com/2012/06/giant-sunspot-fires-two-solar-flares.html and
http://www.dailydisruption.com/2012/06/giant-sunspot-fires-two-solar-flares-toward-earth/.
It is also interesting to see how tabloids in the UK present science articles:
http://www.dailymail.co.uk/sciencetech/article-2161626/.
And last,
http://revmodo.com/2012/06/20/sun-spot-activity-unleashes-solar-flares-geomagnetic-storms-and-stunning-northern-lights/.
Jim Williams, K5NN of Wichita, Kansas wrote in response to last week's bulletin: "Some of the comments on the 1950's 10 meter propagation were interesting. I was first licensed as a teenager in 1952. My first equipment was a Command receiver/transmitter so I could only get on 80/40 meter CW. In 1953 I built a 6L6 Heising modulated rig that could run 6 watts on 10 meters. I was using a borrowed Hallicrafters S20R receiver with a pre-amp. The antenna was a ground plane made out of military surplus steel rod.
"I worked the world! I forget my country total but it was well over 100 by the time I graduated from high school and joined the Air Force. I was not able to return to ham radio till the mid 60s and 10 meters was still very good then. At that time I was able to run many scheduled phone patches from Antarctica and the Military installations in the Pacific on 10 meters into West Texas and New Mexico."
The Command set that K5NN mentioned refers to a huge number of radios available on the surplus market for next to nothing after World War II. With a little modification these could be put on the air, and if you look in old copies of QST and especially (if I recall correctly) CQ magazine in the 40s and 50s, there were many conversion articles based around these radios. I even recall seeing one which converted a command set transmitter to SSB, which involved gutting the unit and using a few key components.
An article on these radios, with nice photos at the bottom is at
http://en.wikipedia.org/wiki/AN/ARC-5. A unique image is at
http://aafradio.org/flightdeck/arc5-1.htm and another is at
http://www.iarc.org/~4z5to/arc.php.
Also check this photo at
http://radios4fun.net/index.php?p=1_26_St-Julians-Massacre which I think might be of surplus radios ready to be dumped in the ocean after WWII. There were just too many to haul back to the United States. At this same site, check
http://radios4fun.net/index.php for many more photos of military radios from that era.
Rob Gregory, KD7H wrote about Fidalgo Island, mentioned in last week's bulletin. Actually I noticed that W7LTQ is in Anacortes, Washington, which is separated from the mainland by a very narrow channel. When you drive there, it is not obvious that you are on an island.
KD7H wrote: "I am a big IOTA fan and I wanted to give you a correction, regarding W7LTQ's QTH. Fidalgo hasn't qualified as being part of IOTA NA-065 for quite some time because it doesn't meet the 'distance from shore' requirement (it's too close to the mainland, of course). The same holds true for Anderson, Camano, Fox, and McNeil islands.
"Regarding propagation, this past week I couldn't get to sleep so I was on HF between 1 and 2am, and was very surprised to be able to work into Europe, including the UK, on 20 and 17 meters (both CW and SSB) and the ZL/VK/JA areas were coming through at the same time. I was running about 400 watts, but only using a G5RV up about 30 feet in fir trees alongside the house. Oddly, during the daylight hours the bands seemed pretty dead in my neighborhood. However, yesterday, Friday, June 15, OD5NJ had quite an amazing signal on 17 meter CW in the late afternoon and it was well past dark at his house. If I can hear good DX on my wire then I can determine that the bands are open - HI! At our latitude, that hasn't happened much since last October. Thankfully, the DX gods smiled when I worked 3C0E, 7O6T, 9N7MD, and A5A (being retired with tons of time helps, too)."
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://arrl.org/propagation-of-rf-signals. For an explanation of the 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. Find more good information and tutorials on propagation at
http://myplace.frontier.com/~k9la/.
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 14 through 20 were 114, 113, 110, 96, 66, 64, and 46, with a mean of 87. 10.7 cm flux was 148.6, 144.9, 134.5, 124, 118, 109.9 and 103.7, with a mean of 126.2. Estimated planetary A indices were 4, 4, 19, 39, 15, 3, and 4, with a mean of 12.6. Estimated mid-latitude A indices were 4, 4, 19, 36, 13, 5, and 4, with a mean of 12.1. NNNN /EX
Topic: Propagation (Read 1006 times)