On Wed, 27 Oct 2010, Stefan Schäfer wrote:
I just saw that the signal on 8970 Hz is strongest at the end, means the last
dash of the "M" while the 1 hour transmission is rather weaker. But my ERP
must have been higher during the 1 hour transmission. There must be some
propagation effects here!!
the grabber was subject to constant tweaking. i was modifying the gain
manually to set it a bit below clipping, and contrast/brightness for best
view constantly. also notice the small gap before the first dash of G and
M - i've switched on the 6470Hz filter, to see if if it was broad enough
to receive both 8970 and 6470Hz (it wasn't, so i switched it back).
there are some propagation effects for sure, but not that much. i guess
that your signal varies as much as the noise, subject to propagation.
also please keep in mind, that i am located in the middle of a large city,
so that there is some man-made noise, which also changes with time (people
turning on the tv for their favourite shows etc).
next time i will leave the gain alone, and maybe record the whole session
to process it later, so that we have a bit more scientific results :)
VY 73
Jacek / SQ5BPF
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