Propagation de K7RA

This bulletin is out a day early. Look for the next bulletin on
Friday, February 23.

The sunspot number is currently 0, and the sun appears spotless, at least from this side. A week ago, helioseismic holography detected a spot on the far side of the sun, but whether it will fade away before reaching our side is unknown. Currently a solar wind is causing geomagnetic instability here on Earth, and the mid-latitude K index is 5 at 0600z on February 15.

This week brought a couple of messages about propagation software. Both noted that this bulletin frequently mentions W6ELprop. This is because it is easy to use and free, as well as being easily available. Each mentioned their favorite propagation software, and wondered why it hasn't been mentioned here.

Steve Hammer, K6SGH of Santa Barbara, California suggested VOAProp from Julian Moss, G4ILO. This is Windows freeware and serves as a front end or shell for the free VOACAP software. To run VOAProp, you download the setup file from, http://www.g4ilo.com/voaprop.html. As
you install VOAProp, it directs the user to the VOACAP download site. When executing the VOACAP setup file, it is best to let it install in its default installation directory right at the root of the hard drive (C:\).

The web site has instructions for using VOAProp, and the first thing you'll want to do is set it up with your own latitude and longitude. Then you click on the Solar Data button, and let it download the predicted smoothed sunspot number for the month, in addition to current data from WWV. Then you can set up the month and year, and if you want, you can easily reset it for sunspot numbers higher or lower than the current one, to try out different scenarios.

The program has a nice map display, and above it are buttons for each of the 9 HF amateur bands, plus 160 meters. Yes, it does include 160 meters, as well as 60 meters and the so-called WARC bands at 12, 17 and 30 meters. Click a band-button, and it displays a contour map showing what signals should be like in all directions from your location. These are similar to contour maps showing
elevation for terrain, or weather maps that display contoured areas for temperature or barometric pressure.

You can also see a 24-hour graph of probable signal levels between you and any particular location. Just click on the map to draw a line from you to any spot. You then click on Show Chart to bring up the graph.

K6SGH has his own useful resources on the web. Go to,
http://www.k6sgh.com/ and look for a link to the Moxon Antenna Project, where you can find plans for simple but effective homebrew gain antennas based on designs by the late Les Moxon, G6XN.

Thomas Otterbein, DG8FBV was the other person who wrote, and he suggested WinCap Wizard from Jim Tabor, KU5S, which is also based on VOACAP. We'll try to get to that soon, but in the meantime check out the KU5S software at, http://www.taborsoft.com/.

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 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 February 8 through 14 were 22, 11, 11, 0, 0, 0 and 0 with a mean of 6.3. 10.7 cm flux was 78.4, 76.7, 75.9, 74.7, 73.6, 72.7, and 72.7, with a mean of 75. Estimated planetary A indices were 7, 4, 3, 2, 7, 17 and 18 with a mean of 8.3. Estimated mid-latitude A indices were 6, 3, 2, 1, 4, 13 and 16, with a mean of 6.4.

Source: The American Radio Relay League

• All propagation reports can be found at:
http://www.southgatearc.org/propagation