VLF: Some screenshots of the 6th experiment

[Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>]

Dear group,

Attached you see some pictures of the QRN Situation and my signal, received on my grabber in Heidelberg. To that time my grabber run in DFCW-240 mode,11,4 mHz FFT, so the S/N could have been some 3 dB better if i would have known the correct TX frequency before and set to DFCW-600/4,5 mHz.
The QRN was at it's minimum at 9:10 UTC, -117 dB. My best radiated signal was arround 14:50 UTC, -91 dB.
So the signal could have been 26 dB above noise or about 30 dB above noise in 4,5 mHz (!). But sadly the QRN was risen to -103 dB to that time.
This means, in the next test, at proper wind and low QRN, the S/N could easily become 14 dB better!

Now, if this signal was received in Bielefeld and near Paris (and maybe in Todmorden! A report will come on this) and could anyway be 14 dB better, imagine what the maximum distance could have been! And imagine how much lower the QRN could even be in a sunday morning in January!

Optimism is realism in that case! :-)

73, Stefan/DK7FC

01082010_9h10UTC_QRN-minimum_-117dB.jpg
Description: JPEG image

6470Hz_first transmission_DK7FC.jpg
Description: JPEG image

6470Hz_overall trace.jpg
Description: JPEG image

6470Hz_highest signal level_-91dB_14h50UTC.jpg
Description: JPEG image