ARRL

ARRL Propagation Bulletin ARLP030 (1998)

SB PROP @ ARL $ARLP030
ARLP030 Propagation de K7VVV

ZCZC AP30
QST de W1AW
Propagation Forecast Bulletin 30  ARLP030
From Tad Cook, K7VVV
Seattle, WA  July 24, 1998
To all radio amateurs

SB PROP ARL ARLP030
ARLP030 Propagation de K7VVV

W9JJ wrote to point out that the statement in last week's bulletin
ARLP029 that a K index of six was bad really only applies to HF
radio.  For VHF operators, geomagnetic disturbances often produce
exciting propagation.  A good VHF rule is when the K index is high
to point your antenna toward the closest polar region, north in the
northern hemisphere and south in the southern to take advantage of
auroral propagation.

Estimated Planetary A indices of 37 on July 16 and again a week
later on July 23 were certainly good times to listen for those
gravelly auroral signals on VHF.  W9JJ reported that when he lived
in Wisconsin he would frequently find auroral propagation on 2
meters when the K index was only three or higher.  When the K index
was six it meant a solid 2 and 6 meter opening.

VHF has been producing a lot of interesting propagation lately, but
not just from auroras.  A lot of Hawaiian signals have been reported
on the West Coast due to tropospheric ducting.  WA6KLK, K6FV and
N6RZ reported hearing the KH6HME 2 meter beacon in Northern
California early in the week, and later it was copied by a number of
Pacific Northwest stations.

A number of stations reported 6 meter openings to Japan.  JH2COZ
worked K7CA in Nevada and heard many JA stations calling N5JHV in
New Mexico and K7FF in California.  G0JHC in Northwest England heard
a VE8 6 meter beacon at S7.

KJ6KO has some .WAV files with recordings of the 6 meter openings
from California to Hawaii at http://www.innercite.com/~kj6ko.

Over the next week look for a rising solar flux, reaching 120 around
July 28 to August 1.  Flux values are expected to drop below 110
around August 7, and above 110 again after mid-August.  Look for
disturbed geomagnetic conditions again around July 30 and 31.

Sunspot Numbers for July 16 through 22 were 113, 89, 76, 62, 90, 125
and 145 with a mean of 100.  10.7 cm flux was 106.2, 100.3, 99.2,
103.6, 111.8, 110.3 and 114.1, with a mean of 106.5, and estimated
planetary A indices were 37, 9, 5, 8, 6, 15, and 8, with a mean of
12.6.
NNNN
/EX