LF: Re: DK7FC's 7th VLF kite experiment

["James Moritz" <james.moritz@btopenworld.com>]

Dear Stefan, LF Group,

Thie attachment shows just over 24h of VLF spectrogram recorded using the 
"wideband.usr" file you posted earlier. The period shown is 1200utc on 7/10 
until 1200utc on 8/1, produced by editing 2 screen shots together.
The noise level about 0 - 5kHz is predominantly mains harmonics, on top of a 
continuum of noise that is due to impulses from an electric fence somewhere 
nearby. Some of the noise is probably internal to the PC. The baseline of 
the spectrum plot effectively shows the low frequency response of the 
antenna/preamp.
The range 5 - 12kHz is dominated by mains-related noise during daylight, 
with QRN rising during darkness. Actually, the mains noise level was lower 
than usual during this period, compared to that during last weekend's 
experiments.
The loop antenna orientation was the same E-W as used during reception of 
DK7FC - this means several of the utilities are significantly attenuated due 
to being away from the maximum directional response of the loop.
Cheers, Jim Moritz
73 de M0BMU

VLF_bmu.jpg
Description: JPEG image