Propagation Forecast Bulletin #21 de K7RA:

ZCZC AP21
QST de W1AW
Propagation Forecast Bulletin 21 ARLP021
>From Tad Cook, K7RA
Seattle, WA May 16, 2008
To all radio amateurs

SB PROP ARL ARLP021
ARLP021 Propagation de K7RA

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 others were Propagation Forecast Bulletins ARLP003, 4, 7 and 8. All of the remaining 16 bulletins had at least one day with sunspots in the reporting period.

Geomagnetic indices were quiet. But next Tuesday, May 20 should be quite active. The 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 to http://tinyurl.com/5qpykr showing low band DTV station info.

The site http://tinyurl.com/5z2ocb links to an article about a Channel 2 DTV signal from Florida received over 1,000 miles away in New England. From http://tinyurl.com/6jxet4 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 http://tinyurl.com/y5c796.

Pat is an avid TV/FM DXer, and has a web page devoted to his interests at, http://home.swbell.net/pjdyer/index.html.

Fred Stone, W8LLY of Bellbrook, Ohio is Director of Engineering for WPTD-TV in Dayton, Ohio, and he noted that post-transition television will be broadcast on Channels 2-51. He said FCC records show Channel 2 stations in Flagstaff AZ, Grand Junction CO, Bangor ME, North Platte NE, Las Vegas NV, Rapid City SD, and Jackson WY.

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

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 May 8 through 14 were 0, 0, 0, 0, 0, 0, and 0 with a mean of 0. 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.
NNNN
/EX

Source: W1AW Bulletin via the ARRL.

There are no comments on this article: Post One