[net.ham-radio] Propagation Bulletin 3

ad7i (01/19/83)

qst de ad7i
red bank, new jersey, u.s.a.
hr propagation forecast bulletin nr 3  from arrl headquarters
newington ct  janqary 16, 1983
to all radio amateurs  bt

major changes in solar activity have occurred in recent weeks.
there was only a slow rise and fall in the solar flux, from 136 to
170, and back down to 140.  the flux was rising gradually after
january 13, but no major peak seems imminent.  flux levels have been
as much as 110 points below those at the same time in the previous
solar rotation.

no large solar flares have been reported, and the average level of
geomagnetic activity has continued much below that of december.  this
made for more stable long distance propagation, partqcularly on h oh
latitude circuits.  the muf was lower in early january, but otherwise
dx conditions have been generally good, except for an absorption peak
january 10 and 11.  there will be higher wwv a and k indices during
much of the forecast week, and conditions will bepsomewhat like those
of january to date.  more stable and generally better conditions are
expected after january 22.

the solar flux is likely to average higher in the last half of
january than in the first half, but the increase will have only a
slight effect on the higher frequency dx bands.  january may have a
solar flux average below that of any month in recent years.

american sunspot numbers for january 6 through 12 ranged from a low
of 67 on the 11th to a high of 110 on the 8th for a mean of 90r4  ar

pbn@hou5a.UUCP (01/18/84)

qst de ad7i
hr propagation bulletin nr 3
newington ct  january 16, 1984
to all radio amateurs  bt

beginning january 6, the solar flux rose gradually, reaching a high
of 106 on the 13th.  it was dropping back as this bulletin was
issued, and the downtrend is expected to continue through the 19th.
there will be only a slight rise thereafter until the end of january.

we have been in a relative period of solar calm for about ten days in
which the muf has been low, but propagation has been generally good
otherwise.  january has been typical of what can be expected for the
next six weeks or so.  propagation changes will be more the result of
the suns move northward than of any major changes in sunspot
activity.

for the forecast week, there will be increasing geomagnetic activity,
which will degrade high latitude circuits mainly.  transequatorial
and other low latitude paths will be mostly good.  no serious
disturbances are expected before the last few days of january.

solar flux numbers are likely to be on the low side for the same
period.  the north atlantic path will continue to be the most
variable, particularly on 21 and 28 mhz.  the latter band will be
useful mainly in the low latitudes and the transequatorial paths.

american sunspot numbers for january 5 through 11 were between 20 and
46, with a mean of 33.4  ar