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Date: Wed, 14 Dec 2016 20:06:37 +0100
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Subject: Re: ULF: Finally 100 mA on 2.97 kHz
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Status: O

Hello Jim, ULF,

Am 13.12.2016 01:13, schrieb hvanesce@comcast.net:
> If you have ruled out phase jumps from corona (which I think you did rule out)
Today i did. I sent an unmodulated carrier from 10:30...18:38 UTC today 
(maybe useful for Paul who's probably working in the background :-) ) 
and monitored the signal in 30m distance. Of course the signal levels 
are very strong there and we can exclude any propagation effects. I can 
confirm there was no change in the colour (equal to the phase) in the 
transmission. It was interesting to see sidebands at +- 0.5 Hz and about 
-50 dBc, which probably come from the samplerate drift compensation 
which happens each second. So it all works as expected. On the tree, the 
colour changes were visible again, but the variations were quite weakly 
expressed today.
>   my next thoughts would include (among other things) variations in diffraction and/or re-radiation from local geography and infrastructure,
I think this is unlikely because there is no electricity on the receive 
site on the tree, nothing like trees and stones in a radius of 1000m.

> If your initial SNR measurements at 65 km are representative (first pixels 20dB at 47 uHz?),
20 dB at 424 uHz, after sferic blanking, in daytime. You're right, i 
should try to
BTW the noise was so low that it looks like i am system noise limited, 
not natural noise limited. So i built a new and better preamp today, 
with two op amp stages, inspirations taken from 
http://www.vlf.it/feletti2/idealloop.html

The VLF/ULF band noise is really very very low these days, i'm regularly 
impressed. Oh and i'm planning a 130 km experiment in the next few 
weeks. Before that i'm doing a local experiment just to test the new 
preamp together with the loop.
In this 130km experiment i will rise the power by 3 dB, about 150 mA 
antenna current. That should be enough to see the signal in that 
distance in 424 uHz. Ah and the plan is to do it in France, JN38OO could 
be the region of interest...

73, Stefan