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- SB PROP @ ARL $ARLP028
- ARLP028 Propagation de KT7H
-
- ZCZC AP42
- QST de W1AW
- Propagation Forecast Bulletin 28 ARLP028
- >From Tad Cook, KT7H
- Seattle, WA July 16, 1994
- To all radio amateurs
-
- SB PROP ARL ARLP028
- ARLP028 Propagation de KT7H
-
- The sunspot count was up a bit last week, but the solar flux was
- about the same as the week before. The sunspot number is based on
- the total area and number of spots visible on the solar surface from
- earth. More sunspots of larger areas generally produce more of the
- sort of radiation that makes the ionosphere reflective.
-
- Solar flux is energy from the Sun measured here on Earth at 10.7 cm
- wavelength, or 2.8 GHz. It correlates fairly closely to the charged
- particles reaching the ionosphere that reflect radio waves.
-
- Geomagnetic disturbances were down last week, with a falling A index
- in the single digits. But on Thursday, the day this bulletin was
- written, the K indices began to rise to four. More active levels
- are forecast for the next couple of days due to a recurring coronal
- hole, an area on the Sun that generates disturbances here on Earth.
- Another period of upset is forecast for July 23 to 28.
-
- Solar flux is expected to stay in the eighties through the rest of
- the month. Broad peaks around 90 may appear centered around July 19
- and August 6.
-
- Sunspot Numbers from July 7 through 13 were 90, 82, 72, 92, 102, 84
- and 81, with a mean of 86.1. 10.7 cm flux was 88.1, 85.8, 85.9, 86,
- 85.6, 82.9 and 81.4, with a mean of 85.1.
-
- The path projection for this weekend is from Cleveland, Ohio to
- Congo.
-
- 80 meters should open from 0030 to 0515z, peaking around 0200. 40
- meters should be good from 2330 to 0530, and 30 meters from 2230 to
- 0600. Check 20 meters from 2100 to 0230, and on some days 17 meters
- may be open from 0000 to 0200. 15 meters and above do not look good
- at this time, but on rare occasions 15 meters may open up after
- sundown on the Cleveland end of the path.
- NNNN
- /EX
-