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The K7RA Solar Update

05/16/2008

We've had another week with no sunspots. Our reporting week for this bulletin runs from Thursday through Wednesday, and this is the fifth bulletin of the year reporting zero sunspots for the week. The rest of the 16 bulletins had at least one day with sunspots in the reporting period. Sunspot numbers for May 8-14 were 0, 0, 0, 0, 0, 0 and 0 with a mean of 0. The 10.7 cm flux was 66.4, 67.3, 67.4, 68, 68, 68.3 and 69 with a mean of 67.8. Estimated planetary A indices were 4, 3, 5, 3, 4, 4 and 3 with a mean of 3.7. Estimated mid-latitude A indices were 3, 3, 4, 3, 3, 3 and 1, with a mean of 2.9.

Geomagnetic indices were quiet. But next Tuesday -- May 20 -- should be quite active. Predicted planetary A index for May 16-22 is 5, 5, 5, 12, 30, 15 and 8. Geophysical Institute Prague expects quiet conditions May 16-18, quiet to unsettled May 19, active geomagnetic conditions May 20, unsettled May 21 and quiet to unsettled May 22.

Last week's bulletin lamented the transition from analog television on channel 2, because signals on that frequency have been a popular indicator for 6 meter DX. Several readers wrote in about the low TV channels 2-6, and mentioned possibilities for continuing to use broadcast transmitters there for propagation beacons. There are also examples of digital TV being received a long distance from the transmitter site.

Patrick Dyer, WA5IYX, of San Antonio, Texas sent in a number of useful links, and mentioned a pilot carrier 310 KHz above the bottom of each DTV channel, useful for detecting skip signals. For channels 2-6, you can plug these frequencies into your scanner: 54.31 MHz, 60.31 MHz, 66.31 MHz, 76.31 MHz and 82.31 MHz. Of course, you would want to skip any frequencies that are used locally. He sent a link showing low band DTV station info.

This link goes to an article about a channel 2 DTV signal from Florida received more than 1000 miles away in New England. You can download a PowerPoint file with info on using pilot signals to detect a DTV station below the level that enables a usable DTV service. If you don't have Microsoft PowerPoint, you can download a free PowerPoint viewer from here. Pat is an avid TV/FM DXer and has a Web page devoted to his interests.

Fred Stone, W8LLY of Bellbrook, Ohio, is director of engineering for WPTD-TV in Dayton, and he noted that post-transition television will be broadcast on channels 2-51. He said FCC records show channel 2 stations in Flagstaff, Arizona; Grand Junction, Colorado; Bangor, Maine; North Platte, Nebraska; Las Vegas, Nevada; Rapid City, South Dakota, and Jackson, Wyoming.

Jon Jones, N0JK, of Wichita, Kansas, reported widespread 6 meter E-skip openings May 13 in the USA from 1900-0300 UTC.

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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