Dear LF Group,
Not very much time for LF activity over the weekend, but here are
a few things which happened:
I recorded and decoded IK5ZPV's Wolf signal at 10W level again
on Thursday night. I also monitored 137.79kHz for VA3LK's Wolf
beacon sigs on several occasions overnight, but nothing was
detected.
On Sunday morning I worked G8RW and DF0WD on CW, and
called OK1DTN, who was a 549 signal with me, but no reply.
On Sunday evening, I took part in some Wolf-mode tests with
DF0WD. As Wolf-DL4YHF remarked, I was not able to decode
these, but I still have the recordings, and from the info provided, I
hope to be able to calculate the appropriate correction factors to
make it work, once I have finished scratching my head! The CW
talkback was quite hard work, with the evening QRN making
DF0WD only R2 at times.
I have been playing with some BPSK modulator circuits, and am
currently putting together details for for the variable-phase
modulator I tried out recently, plus also a linear BPSK exiter, which
takes 137kHz carrier and logic-level BPSK signal, and generates
an envelope shaped BPSK signal of a few V pk-pk for driving a
linear PA.
On Sunday afternoon, I heard and saw on the spectrogram screen
a weak FSK - like signal centred on 137.4kHz with about 80-100Hz
shift. I wonder if this was an amateur or professional signal?
I am thinking of putting on some more Wolf beacon signals later on
this week, say Wednesday and Thursday evenings from about
2000utc - Would anybody like specific power levels? Is 137.5kHz
OK, or should I QSY?
I will certainly try to make it to the LF Forum in May - I can't see
any reason why I wouldn't be there at the moment.
Cheers, Jim Moritz
73 de M0BMU
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