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RE: LF: Daytime 29.499 kHz

To: "[email protected]" <[email protected]>
Subject: RE: LF: Daytime 29.499 kHz
From: Bob Raide <[email protected]>
Date: Sat, 8 Mar 2014 12:32:56 -0500
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Paul;
It is not only the ground but the air temp has great influence and maybe much more than the shallow depths of the ground freezing-Bob
 
> Date: Sat, 8 Mar 2014 17:06:09 +0000
> From: [email protected]
> To: [email protected]
> Subject: Re: LF: Daytime 29.499 kHz
>
>
> Bob wrote:
>
> > Wonder what effects soil conductivity changes has on the
> > propagation at these VLF freqs??
>
> I have no information. You would expect ground resistance
> to rise, but would that make noticeable difference to
> propagation if it is only a freezing of a shallow surface
> layer?
>
> I had to go to a narrower bandwidth to produce phase and
> amplitude plots for last night's test
>
> http://abelian.org/vlf/tmp/29499_140308a.gif
>
> Signal is down by some 5dB compared with some recent
> tests.
>
> Nothing detected this afternoon.
>
> Propagation seems normal, noise floor normal.
>
> Maybe the cold and frozen ground is affecting the tx
> efficiency, some lower Q of the loading coil - antenna -
> ground loop, or a reduction of effective height.
>
> Will be interesting to see what happens after the thaw.
>
> --
> Paul Nicholson
> --
>
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