A 120KW ERP at the end of the antenna is impressive... But what is the power
density at 10 wavelengths, a thousand wave lengths, ten thousand
wavelengths, a hundred thousand wavelengths?
Hint: The formula to calculate the change in power density for a change in
distance is found near the front of any antenna theory textbook...
Even multiplying the ERP by a few thousand amateur stations at the height of
a contest and the power density at 200 miles in the ionosphere is still
extremely small, especially compared to ionic excitation from thermal
energy, energy from lightning strikes, and most assuredly compared to the
ravening UV, Xray, and Gamma energy of the sun at those altitudes...
The statement that ham activity has a measurable effect upon ion spin and
density at 200 miles up, much less a significant impact, is upon the face of
it liken to the old advertising slogan, "Makes your teeth 100% whiter."....
Denny
----- Original Message -----
From: <DF3KV@aol.com>
To: <K3BU@aol.com>; <cq-contest@contesting.com>
Sent: Thursday, April 05, 2001 10:02 PM
Subject: Re: [CQ-Contest] Ionospheric heating
>
>
>
> I found similar effects are regular and reproducable on VHF.
> 2 or 3 time the week I schedule with a friend about 350km from
> my qth on 144Mc.
> When we start signal strength is around S9.
> After about 20 minutes signals are up to 9+20 and stay that high.
> ERP on both sites is around 120KW.
>
> More then 30 years I serviced a forward scatter station near cologne
> running at 70Mc.
> ERP was enormous with the 45m dish and a klystron amp, but the 800km path
was
> reliable with 99,99% ( 0,1% due to service ) to Verona, Italy.
> Information transmitted were 120 RTTY channels.
>
> On HF so far I did notice similar effects only on backscatter, but might
be
> worth to run some tests with overseas stations point to point.
>
> 73 de Peter, DF3KV
>
>
>
> --
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>
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