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ARRL Propagation Bulletin ARLP029 (1997)

ARLP029 Propagation de K7VVV

Propagation Forecast Bulletin 29  ARLP029
From Tad Cook, K7VVV
Seattle, WA  July 18, 1997
To all radio amateurs

ARLP029 Propagation de K7VVV

Conditions are still poor because of low solar activity.  While HF
radio enthusiasts can be pleased by the continued stable geomagnetic
conditions, any new solar cycle still seems to be stalled.  No
change is forecast for the next few weeks.

The average solar flux for the previous ninety days has dropped
another point this week to 72.  This is the second time in July that
the ninety day flux average has dropped, and the flux values on each
day last week were well below that number.

K8MLV wrote to point out that in propagation bulletin ARLP028 there
were a couple of flux values which seemed to vary from the values
broadcast by WWV.  The solar flux values in this bulletin are from
the observatory in Penticton, BC, and another check with the numbers
from the observatory agree with the values in ARLP028.

K8MLV also mentioned that the flux value for Saturday, July 12 was
the lowest since last October 12, and that CO2KK in Radio Havana
Cuba recently speculated on the possibility of a second solar
activity minimum before solar cycle 23 takes off.

Jan Alvestad wrote from Norway to tell us about a nice web site he
built at which is devoted to sunspots and
solar activity.  Check it out.

W4AR wrote from Florida to say that during last weekend's VHF
contest there was little or no 6 meter activity, which he believes
is connected to the low solar activity.  N3EG wrote from Washington
state to note that there were no sporadic E signals at his QTH
during the same contest, just a few meteor bursts.

Sunspot Numbers for July 10 through 16 were 17, 0, 0, 0, 11, 0 and 0
with a mean of 4.  10.7 cm flux was 68.5, 68.6, 67.4, 67.1, 68.1,
69.2 and 69.6, with a mean of 68.4, and estimated planetary A
indices were 8, 4, 4, 4, 3, 14, and 5, with a mean of 6.


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