Hope the attached .JPG image is passed over this reflector, especially after
the recent comment about file sizes, but at only 10k size, we can hope
......
This waterfall plot is a recording of VE1ZZ's signal taken over the period
2130 to 2310z tonight in a bandwidth of 0.05Hz. Obviously no SLOWCW is
visible at this bandwidth, but the signals appearing for 10 minutes on the
hour and half hour would seem conclusive. Also, observe the frequency is
more accurately on 136500 now - no longer 2 Hz high - but there is some
instability during the transmission period, about 0.08Hz drift during the 10
minutes at 2230z
This plot clearly shows the strength of the signal varying over the evening,
although no signal indication is given, another part of this software does
give the proper spectrum and hence signal strength above noise. During the
2300z transmission it was 15 to 20 above noise level in this bandwidth.
This equates to 8 - 13dB S/N in the 0.25Hz (is that right ?) needed for
decoding of the dot length in use. The transmission was at its strongest
in the 2200z period, but I wasn't looking at the plot then to measure !
If Jack is going to continue testing then I will complete the beacon signal
monitoring and logging CFAR software started a few months ago, but
abandonned at that time as no one seemed to want to transmit carrier-like
signals at that time. This will automatically monitor a bandwidth and look
for CW / carrier signals appearing at a certain threshold above the noise,
logging these to disc when thay appear.
Andy G4JNT
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