>From Dave G3YMC
The RTTY signal which has reappeared on or around 137kHz is the self same
signal we were discussing in January and at various other times. It
appears for a few days at a time and then disappears for a month or so. It
has the definite characteristics of a transatlantic signal, being inaudible
during the day, appearing in the late evening and being quite strong around
dawn. It disappears around one hour after dawn, although I have heard it
rather later in the morning and once in the mid afternoon. Very
characteristic of US amateur signals on 160m.
I agree. This was also observed this time last year, too.
Last night the signal was about S2 during the late evening and
when I checked it again at 0030UTC it was S7 and stayed at that
strength until I stopped listening at 0230. I did not experience any
QSB. It was not audible at 0800. I make the shift 75Hz.
On a similar subject, it would be really useful to be able to plot
signal strength against time (say, 24 hours) using a computer - for
simplicity it would help to use the sound card so that the same
connection can be used as Spectrogram. It is =just= possible to
do this with Spectrogram, though the amplitude resolution is poor
and only ten minutes or so can be moniored. Does such software
exist? Yes, I know I can build an A-D converter and write software
etc, etc but if someone has already done the work so much the
better.
Mike, G3XDV (IO91VT)
http://www.dennison.demon.co.uk/activity.htm
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