Dear LF Group,
As part of some experiments with GPS-locked PSK modulation for LF, I hope
to run some TX tests tonight. I plan to transmit on 137.5000 kHz, running
high power from about 2000utc - 2100utc, and reducing power to about 10W
(about 5mW ERP) after that for a few hours. The modulation will consist of
a sequence of 12 bits, with a bit period of 10 seconds, repeating every 2
minutes. The start of the sequence will be synchronized with the utc hour,
so a new sequence will begin at the start of each even minute. Both the
carrier frequency and phase keying are derived via a GPS time/frequency
receiver, so should be very accurate. Received aurally or using
spectrogram-type software (I would suggest settings as for QRSS3), the
signal will just be a carrier with "clicks" occurring at the phase
transitions. Any reports will be very welcome.
Cheers, Jim Moritz
73 de M0BMU
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