SB PROP ARL ARLP002

ARLP002 Propagation de K7RA

If you haven't heard, the big geomagnetic storm predicted for

yesterday, Thursday, January 9, did not happen. Planetary A index

was predicted to be 73 for the day, and instead it was a quiet and

stable 10. The planetary A index predicted for today, January 10, is

41. The latest forecast from late Thursday has revised that to 40.

If the planetary A index had reached 73 yesterday, it would have

been historic. You have to look way back to December 15, 2006 to

find anything stronger.

But this has been an exciting week for Sun watchers. The daily

sunspot number reached 245 on January 6, and solar flux was 237.1 on

January 8. This may turn out to be a strong second peak for Cycle

24.

The GOES-15 x-ray background flux has also been high, and may be

more significant for enhanced HF propagation than a high solar flux.

You can see daily x-ray flux values here:

http://www.swpc.noaa.gov/ftpdir/latest/DSD.txt

For historical values of x-ray flux, solar flux and sunspot numbers

check the links marked DSD.txt:

http://www.swpc.noaa.gov/ftpdir/indices/old_indices/

The links marked DGD.txt will give you daily geomagnetic indicators.

The Australian Government Bureau of Meteorology has a brief

explanation of x-ray flux at http://www.ips.gov.au/Educational/2/1/3

.

Over the past week, average daily sunspot numbers rose more than 80

points to 188.1, and average daily solar flux was up more than 62

points to 201.6.

Predicted solar flux for the next few days has been adjusted

downward about 11 points from Wednesday's forecast. The latest

prediction has solar flux of 184 on January 10-12, 175 on January

13, 155 on January 14, 150 on January 15-19, 155 on January 20, 160

on January 21-23, and 165 on January 24-26. It then rises to a peak

of 190 on January 29 through February 3, and declines to a minimum

of 140 on February 12-16 before rising again.

Predicted planetary A index values are 40, 15 and 8 on January

10-12, 5 on January 13-22, 10 on January 23, 8 on January 24, 5 on

January 25-27, then 10, 18 and 8 on January 28-30, then 5 again

until it hits 12 and 8 on February 6-7.

F.K. Janda, OK1HH has a short prediction for us this week. He sees

quiet to unsettled geomagnetic conditions on January 10, quiet to

active January 11, quiet to unsettled January 12, and mostly quiet

January 13-17.

Mike Stein, WB9NOO of Fort Wayne, Indiana sent an interesting report

on a sporadic-E event.

"I am a broadcast engineer at WANE-TV in Fort Wayne, Indiana.

Thursday, Jan 2 at noon, we were doing a live report from our remote

truck. We were using our IFB transmitter, running 1 watt FM into a

quarter-wave whip on 26.35 MHz, which transmits our off air audio to

the reporter a few feet away.

"After the newscast I received an e-mail from David E. Crawford in

Indian River City, Florida, who had received our signal. He was

using a Drake R8 receiver and 170 foot longwire 20 feet above

ground.

"He sent us pictures of his equipment and a recording, requesting a

QSL card.

"That was certainly exciting on both ends!"

IFB stands for "Interruptible Foldback" or "Interruptible Feedback,"

the low power system that transmits either cues from a director or

in this case audio off the air to a news reporter. Intended to

travel just a few feet, the signal made a roughly 900 mile trip to

Central Florida. Of course, they were using a full watt into a

quarter-wave whip, which at 26.35 MHz would be about 8 feet, 10

inches long.

I believe the SWL at the other end is probably KD4WHZ.

Bob Foster, N9BGC of Waverly, Iowa writes: "The best techniques I

have found this winter: 1) start high in frequency and work lower;

2) seek out the various beacons; 3) be aware of the LUF (Lowest

Useable Frequency) predictions found on the ARRL website. Those

techniques resulted in numerous DX contacts. Finally, don't be

discouraged if the DX isn't pounding into your shack. I had some

very enjoyable domestic QSOs this past week, when the DX was hard to

find."

The LUF predictions are in the propagation charts mentioned at the

bottom of this bulletin. LUF is shown as a blue line toward the

bottom of the charts.

Dennis Condron, K0LGI of Marion, Iowa sent information about

monitoring radio signals reflected from meteor trails. He and KB5VL

have a lot of material on this at,

http://www.roswellmeteor.com/default.htm . An interesting

description of what they do is at,

http://www.roswellmeteor.com/Receiving%20Meteor%20Reflections%20Using%20DTV%20Transmitters.pdf

.

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. 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 January 2 through 8 were 133, 162, 178, 225,

245, 196, and 178, with a mean of 188.1. 10.7 cm flux was 160.5,

182.3, 215, 217.5, 203.9, 237.1, and 194.6, with a mean of 201.6.

Estimated planetary A indices were 20, 20, 6, 4, 4, 8, and 8, with a

mean of 10. Estimated mid-latitude A indices were 15, 7, 6, 4, 4, 7,

and 8, with a mean of 7.3.

NNNN

/EX