R: SLF: Carrier transmission at 80 Hz

["marcocadeddu@tin.it" <marcocadeddu@tin.it>]

ehm... some time ago I wrote here that there were worries at the Pentagon :-))))
 
simply incredible!

If next weekend I ear some hum coming from my devices now I know who is guilty! ;-)))

FB

Marco, Ik1HSS

----Messaggio originale----
Da: selberdenken@posteo.de
Data: 23-nov-2018 10.21
A: <rsgb_lf_group@blacksheep.org>
Ogg: SLF: Carrier transmission at 80 Hz





Dear SLF friends, 

A new step forward towards DC: Since yesterday 22:30 UTC i'm TXing a
carrier at 80.005 Hz. That's the 3750 km band, where
the far field begins at a distance of 598 km.

The antenna voltage is just 5 kV and i'm getting 1.2 mA antenna
current, giving an ERP of  20 fW (2E-14 W).

The voltage is even higher than in my recent experiment on 270 Hz,
anyway the S/N is lower, indicating that my RX lacks of sensitivity.
Indeed this experiment helps to estimate the lack of sensitivity. Looks
like i'm missing about 10 dB on that frequency. Anyway the signal is
making the path of 3.5 km to my tree grabber, as usual shown at
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html.
Not a big distance but still well beyond most garden fences!
The signal leaves a barely visible trace in the ZEVS window which is
running at 3.8 mHz FFT bin witdh. Unfortunately ZEVS is off the air
since a week or so. actually i wanted to transmit side by side with
ZEVS, of course a bit deeper even.

>From a quiet period at night, i calculated the SNR of a 1 hour carrier
period using vlfrx-tools: carrier S/N: 16.83 dB in 277.8 uHz,
-18.73 dB in 1Hz

For the crazy homebrewers i'd like to share that website where i
ordered the HV-transformer,
http://www.hosin.de/Specials/HV-Trafo/hv-trafo.html A nightmare for all
safety-fetishists! For the completeness it must be mentioned together
with that page: http://kurts-werkstatt.de/hv-trafo.htm

73, Stefan