Re: VLF Sunrise Sunset effect at VLF using SDR and "LIL" Low Impedance Loop


I was thinking of a full spectrum width snap shot taken periodically so that all active channels can be shown fading and possibly, with enough frequency granularity, show the signal frequency change during your plot around 03:00:00. Different channel paths will show different fading times. And the 3 D view would probably be quite artistic.


On 20210707 22:15:26, Jean-Marie Polard wrote:
Here is such a plot of amplitude of DCF77 during half night and sunrise (a time signal vlf station in Germany) done with vlfrxtools of Paul Nicholson. But with Spectrum Lab one can do the same. Received with an UMC202HD usb soundcard and earth probes antenna

73's Jean Marie F5VLB

Le 08/07/2021 à 07:11, jdow a écrit :
That brings to mind a possibly interesting feature for people into observing changes in propagation would be a means of creating VERY slow waterfall images, once a second, once in 10 seconds, once a minute, once in ten minutes, etc, probably in a traditional 1,2,5,10 sequence. Then you watch the pips move and change with time. With a fine enough spectrum plot you can possibly actually see the frequency changes as the ionosphere moves up and down and the D layer comes in and out. It could be used for education.


On 20210707 20:17:02, wrote:
have a look here also :

Jean-Marie Polard

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