LF: 0...36 kHz recording, 4 hours from a quiet location

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

Hi Henny, VLF

Thanks for your transmission.
It was a nice day and i took a 4 hour recording during climbing on trees, sleeping and eating in a hammok :-)
Right now i'm running various reprocessings and hope to find your signal out of the noise. I will post screenshots of the complete session later.

If someone wants to play with the recording wav file, it is available at http://dl.dropbox.com/u/19882028/LF/audio/EfieldSteinbruchOhne5k6ExtAkku.WAV for a while. It is a 1.95 GB file sampled at 72 k/s.

I switched a 1 MOhm resistor in series to the 5k6 resistor of my active receive antenna. The 5k6 resistor should form a high pass with the 10 nF capacitor in the circuit (http://www.iup.uni-heidelberg.de/schaefer_vlf/8,97kHz%20active%20E%20field%20antenna%20by%20DK7FC.jpg) By adding the 1 MOhm resistor in series it was clearly seen that the lower cut off frequency dropped to < 1 kHz. The highpass was intended to reduce mains hum and all the stuff below 4 kHz but there in the forest, this is no problem :-)

73, Stefan/DK7FC

PS: On my VLF grabber in the city i see a trace at 8970.002 Hz, maybe this was DF6NM transmitting a test signal too?

Am 02.04.2012 10:11, schrieb henny van elst:

Gm Stefan,lf

the tx is on,8.970 Khz

henny cpm

73's