ULF,
Last night, before starting to TX, i started a record of the VLF
(0...16 kHz) streams by IK1QFK and also by SQ5BPF. During the
transmission period there was no break of the streams, good.
Meanwhile the post-processing for the data file shows that the message
is also decodable at IK1QFK, who is in 493 km distance,
http://k7fry.com/grid/?qth=JN39WI&from=JN34RW
Renatos stream is from the E field. The angle between my loop and his
QTH is 54 deg, so there will be some directional loss.
Attached is a screenshot showing the processing chain and the decode
result as well as the SNR, 16.09 dB!
So this transmission was also decoded in Italy which certainly is a
first ULF message detection DL > I.
Thanks to Renato for providing the stream and to Paul for hosting it.
73, Stefan
Am 06.04.2019 22:39, schrieb DK7FC:
Hello Markus, ULF,
I'm now sitting in my car, TXing in the forest. It is very silent here.
I can hear a faint 'crk' in the FETs when the phase toggles :-)
Getting 2.44 A now on the 1130mground loop, 487 W TX power (not as much
as it could be for the planned TX time though).
Now, message parameters:
f = 2970.1 Hz
Start time: 06.APR.2019 20:25:00.3 UTC
Symbol period: 6 s
Characters: 7
CRC bits: 16
Coding 16K21A
Antenna current: 2.4 A
Duration: 02:04:48 [hh:mm:ss]
Reports welcome :-)
73, Stefan
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2970Hz_1130m-ground-loop_EbNaut_IK1QFK_RX.png
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