Hello to my fellow hamateur radio and SWL radio enthusiasts around the world.
Welcome to my “not for profit” W4HM Daily HF Radio Wave Propagation
Forecast.
If you find this daily HF radio wave propagation forecast
useful to your hamateur and SWL radio activities, feel free to drop me a line
and let me know that at
thomasfgiella@gmail.com .
Feel free
without prior permission to redistribute this daily HF radio wave propagation
forecast, as long as you redistribute it in its entirety and give me credit for
it.
Supporting images associated with my daily HF radio wave propagation
forecast can be found in my Facebook account at
https://www.facebook.com/thomasfranklingiellaw4hm
and
at
http://lists.contesting.com/mailman/listinfo/spaceweather
but
without supporting images.
It's a NO SPAM voluntary "opt" in email type
group hosted by contesting on line (COL), so you have to sign up by using an
existing email address and creating a password.
And last but not least I
also post some snippets of solar, space and geomagnetic weather goings on and
some images in my Twitter account at https://twitter.com/GiellaW4hm
.
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#266
Issued Saturday September 23, 2017 at 1500 UTC
Global Daily HF Radio Wave
Propagation Forecast-
We are now entering the fall/spring equinox type
of HF radio wave propagation conditions. Globally HF radio wave propagation
conditions are most evenly balanced across the equator during the fall and
spring equinox.
HF radio wave propagation conditions trend-
improving.
Northern Hemisphere Radio Wave Propagation
Forecast-
80-60 (75-60) meters- good at night and poor at day,
40-30
(41-25) meters- good at night and fair at day,
20-17 (22-15) meters- very
poor at night and good at day,
15 (13) meters- very poor at night and fair
to good at day,
12 (11) meters- very poor at night and fair at day.
10
(11) meters- very poor at night and poor to fair at day.
During the
northern hemisphere winter season the higher HF bands of 10-20 meters (11-19
meters) will close sooner due to less sun light time wise illuminating the
ionosphere than in the summer season. But the maximum useable frequency (MUF) is
higher in the northern hemisphere as the F layer of the ionosphere is lower in
height and is more dense.
Southern Hemisphere Radio Wave Propagation
Forecast-
80-60 (75-60) meters- good at night and poor at day,
40-30
(41-25) meters- good at night and fair at day,
20-17 (22-15) meters- very
poor at night and good at day,
15 (13) meters- very poor at night and fair
to good at day,
12 (11) meters- very poor at night and fair at day.
10
(11) meters- very poor at night and poor to fair at day.
Keep in mind
that almost daily during the southern hemisphere summer season you will find
that the 10 (11) meter bands will open via short north-south and east-west
propagation paths via sporadic E (Es). Also when multiple sporadic E (Es) clouds
form and line up favorably much longer propagation paths open up on east-west
paths. And last but not least north-south propagation paths occur across the
equator via trans equatorial propagation (TEP).
Received RF signal
strength scale-
Very Good- +1 over S9 Or Greater
Good- S7-9
Fair-
S4-6
Poor- S1-3
Very Poor- S0
Meter Band Equivalents
Ham &
SWL
160-> 90
80-> 75
60-> 60
40-> 49,
41
30-> 31, 25
20-> 22, 19
17-> 16,
15
15-> 13
12,10->
11
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This
HF Radio wave propagation forecast is produced based on the SIGINT_CAP HF radio
wave propagation prediction software. I wrote it beginning in the late 1980’s
but I’m sorry to say that it can’t be distributed to the general
public.
And though this HF radio wave propagation forecast is produced
based on the SIGINT_CAP, I do check the actual band conditions at my location in
the USA and tweak the forecast manually where and when necessary. I also check
global HF radio wave propagation conditions via remoted radio receivers around
on every continent of the globe and tweak the forecast manually if and when
necessary.
The hamateur radio JT65A mode RF signal levels received are
based on 5 watts and ½ wave dipole up at 40 feet.
The hamateur radio
PSK31 mode RF signal levels received are based on 25 watts and ½ wave dipole up
at 40 feet.
The hamateur radio CW mode RF signal levels received are
based on 50 watts and ½ wave dipole up at 40 feet.
The hamateur radio SSB
RF mode signal levels received are based on 100 watts and ½ wave dipole up at 40
feet.
The HF shortwave broadcast band AM Mode RF signal levels are based
on 100,000 watts (100 kw) and a typical high gain VOA type curtain array
antenna.
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Please
keep in mind that this is a relatively simplified HF radio wave
propagation
forecast, so as to keep it easily understandable and applicable by the average
radio enthusiast.
Globally HF radio wave propagation conditions are most
evenly balanced
during the fall and spring equinoxes and most diametrically
opposed during
the summer and winter solstices.
Conditions change
daily, weekly, monthly, yearly and by decade, as the
sun rises and sets at
different times and at different angles from the
ecliptic, as well as by
radio wave frequency. This is due to changes in the
maximum usable frequency
(MUF), lowest usable frequency (LUF) and F layer
critical frequency
(FoF2).
The D and E layers also come into play through RF radio wave
signal
absorption and refraction. And then there is sporadic E (Es) radio
wave
propagation that can really throw a wrench into the gears so to
speak.
Things like sporadic E (Es) radio wave propagation and lightning
storm
static can impact HF radio wave propagation in an unpredictable manner
and
mostly bad.
Ongoing solar, space and geomagnetic weather goings
on also impact HF radio
wave propagation conditions in a negative
manner.
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Standard
Disclaimer-
Note! I use error prone RAW public domain data from the NOAA
Space
Environment Center, other U.S. government entities and educational
institutions, to produce this daily HF radio wave propagation
forecast.
This data is gathered and made public by the U.S. Government using
taxpayer
$$$ (including mine).
However this daily HF propagation forecast that I
produce from the RAW public domain data is my personal intellectual property.
Therefore this daily HF radio wave propagation forecast contained herein is
copyrighted © 1988-2017 by Thomas F. Giella, W4HM.
Feel free without
prior permission to redistribute this daily HF radio wave propagation forecast,
as long as you redistribute it in its entirety and
give me credit for
it.
Also HF radio wave propagation forecasting is still an inexact
science. The forecasts are not official but for educational and hobby
related purposes only and are subject to human error and acts of God,
therefore no guarantee or warranty implied.
