Mall,
I agree with you. Ideally one should have a fixed antenna for transmit. In
practice this is not always possible and, even when it is, one cannot always
choose the ideal site.
In many ways, amateur radio is like observational astronomy. You cannot control
the motions of the astronomical objects you are interested in, so you just have
to cope with an imperfect situation. For example, you cannot control when
meteors appear in the sky, yet people have done useful work on meteor scatter.
You seem to have identified three major variables in Ossi's experiments:
propagation effects, the antenna current and the inclination of the antenna.
They may or may not be connected.
Jim's graph shows a periodicity of about 1.4 cycles per hour*. Would it be
possible with suitable mathematical techniques (FFT, deconvolution etc) to
analyse his raw data with a view to separating the three effects?
Data on antenna current and inclination would also help the analysis.
73
John F5VLF
*I do not think it would be helpful to quote that in uHz
On 8 Feb 2011, at 00:35CET, mal hamilton wrote:
> Jim
> The variations in signal you observed was due to the Balloon being buffeted
> about due to wind, thermal dynamics, and up drafts and not a valid
> propagation study. I was in touch with Ossi and he described to me that the
> baloon was almost horizontal at times, therefore the wire antenna attached
> would vary from vertical, slant, horizontal.
> He also said that the antenna current was well down at times, so many
> variables effecting the transmitted signal. All the facts have to be
> gathered before a valid observation is made otherwise its all Guesswork and
> supposition.
> To do a meaningful propagation study the transmitted signal needs to be
> launched from a FIXED antenna.
> The same criteria applies to Kite borne antennas.
> mal/g3kev
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