LF Group
Yesterday I increased my TX power on 500KHz
by 10dB so as to expand my coverage, maybe the QRPp 13uW ERP has reached its
limits.
130uW ERP brought M0LMH into my WSPR
coverage (ON,PA,DL and GM4SLV at 890Km too).
I am not a dog lover but I do tend to
associate dog breeds with people, it takes a Rottweiler, (or 2) to get hold of
an idea, stick with it and produce a complete system like WSPR. It takes
a Bloodhound to search out the QRSS3 on my weak signal, M0LMH is the
Bloodhound.
The practical test of WSPR copy-ability
against QRSS3 FSK on 500KHz confirmed the expected. Only M0LMH knows the
precise comparative noise and levels of difficulty.
As I see it, WSPR decoded CALL – LOC
- POWER information at -27dB. At this level The QRSS3 content was visible but
undecipherable. Not until there was a drop in QRN / QRM did it become possible
to read a 2 letter Ident. Later, as the noise dropped, more information was
readable using 3 level QRSS3 with equal Dot and Dash lengths. Following that,
with even less noise, 5 unit Hell became almost 100% readable but not quite. I
don’t know if my signal was audible at any time, which would have enabled
any copy by ear.
Congratulations and thanks to M0LMH for a
most interesting test.
Eddie G3ZJO
