| July, 2008 |  |
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WA7BNM Contest Calendar
(Thanks, Bruce, WA7BNM) |
ARRL DX Bulletin
BWI is Wi-Fi Accessible
|
ARLP025 Propagation de K7RA
Sunspot 998 emerged this week, another old Cycle 23 sunspot near the equator. Daily sunspot numbers for
June 10-12 were 14, 11 and 13. Last Sunday, June 8 had the lowest 10.7 cm solar flux value I've ever seen,
64.9 at the observatory in Penticton. The noon reading is the official daily sunspot number, and the value
observed that morning at 1700z was actually a tiny bit lower at 64.8. The only value this low I have in my
records was almost a dozen years ago near the last solar minimum, July 19, 1996.
10.7 cm solar flux is a measurement of energy at 2.8 GHz, gathered by an antenna in British Columbia.
The facility is the Dominion Radio Astrophysical Observatory, which sits 168 miles northeast of my Seattle
location at approximately 49.322 degrees North latitude, 119.621 degrees West longitude. The solar flux
value is a general indicator of solar activity, but not as useful as sunspot numbers for predicting propagation.
You can see all three daily flux readings at
http://lynx.drao.nrc.ca/pub/solar/FLUX_DATA/fluxtablerolling.text
Hein Hvatum, N4FWA (SK)
Hein Hvatum, N4FWA, who in the 1970s and 80s supervised construction of one of the world's most powerful
radio observatories, died of cancer May 22 at his home in Charlottesville, Virginia. He was 85. In 1974,
Hvatum assumed responsibility for construction of the National
Radio Astronomy Observatory's Very Large Array (VLA),
an arrangement of radio telescopes near Socorro, New Mexico. The observatory is perhaps best known to the
general public for its appearance in the 1997 movie
Contact with
Jodie Foster; it has also appeared in Carl Sagan's documentary
Cosmos,
in the movie Independence
Day, in a Bon Jovi music video
and on the cover of a Dire Straits album.
The VLA was completed in 1982.
| July, 2008 | |
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