Colin, K7FM
-----Original Message-----
From: Michael Tope <W4EF@dellroy.com>
Sent: Feb 7, 2005 8:50 AM
To: K3BU@aol.com, amps@contesting.com
Subject: Re: [Amps] 10dB and propagation
----- Original Message -----
From: <K3BU@aol.com>
Call me old wife, but we have noticed that after the major contest,
bands
seem to be "conditioned" to propagate better for a while, about half
an
hour
after the bedlam stops. I had numerous skeds with OK2RZ on 40m right
after
the
contest and our signals would take a dive after about 1/2 hour. While
at
other,
non-contest times, at the same time we did not see that effect.
If you consider really thousands of kWs and high gain antennas during
the
contests, in view of now knowing about ionospheric heating (HAARP), I
would not
completely dismiss the effect. There might be even selective "heat
your
own
frequency" effect.
FWIW, here are the HAARP antenna specifications:
http://www.haarp.alaska.edu/haarp/ant4.html
Maximum gain is 20dB at 3 MHz increasing to 30dB at
10 MHz. The array consists of 180 elements crossed dipole
elements each with two 10KW sources (3.6 MW total RF
power). That corresponds to 3.6 Gigawatts EIRP at 10 MHz
(equivalent to 36,000 plywood boxes at 3 MHz and
360,000 plywood boxes at 10 MHz). Elsewhere they
state that maximum power density achieved in the
ionosphere is on the order of 3 microwatts/cm^2. That is
roughly equivalent to 30mW/meter^2 or about 30,000 times
what I estimated for Rich's plywood box setup. Despite all
this juice, they state the following:
http://www.haarp.alaska.edu/haarp/tech.html
"The intensity of the HF signal in the ionosphere
is less than 3 microwatts per cm2, tens of thousands
of times less than the Sun's natural electromagnetic
radiation reaching the earth and hundreds of times less
than even the normal random variations in intensity of
the Sun's natural ultraviolet (UV) energy which creates
the ionosphere. The small effects that are produced,
however, can be observed with the sensitive scientific
instruments installed at the HAARP facility and these
observations can provide new information about the
dynamics of plasmas and new insight into the processes
of solar-terrestrial interactions."
73 de Mike, W4EF..................................
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