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


Nick Hall-Patch
 

Would  SDR Console's Data Analyser do what you're suggesting?  

Carrier Sleuth ( https://www.blackcatsystems.com/software/medium_wave_carrier_display_app.html )  can also display carrier shifts and smearing due to propagation changes.



Nick



At 05:11 2021-07-08, jdow wrote:
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, f5vlb.jmp@... wrote:
have a look here also : https://www.facebook.com/groups/VLF.ULF.ELF

Nick Hall-Patch
Victoria, BC
Canada


kb3cs
 

the signal amplitude change over time is interesting .. but so, too, are the small changes in signal frequency caused by the acceleration and deceleration where the signal refraction takes place. 'good' measurements can be had starting with chip-sized TCXO references of the kind now cheap and prevalent. a GPSDO is quite sufficient for 'better' than 'good'.

On Wed, Jul 7, 2021 at 10:27 PM, 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
[...]


aad vander kooij
 

This is more or less what the Satnford Solar Sid does :http://solar-center.stanford.edu/SID/sidmonitor/
As far as I know, the data is public...
73 PD0AK


jdow
 

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, f5vlb.jmp@... wrote:
have a look here also : https://www.facebook.com/groups/VLF.ULF.ELF


-- 
Jean-Marie Polard
F5VLB

http://www.polard.fr/


Jean-Marie Polard <contact@...>
 

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, f5vlb.jmp@... wrote:
have a look here also : https://www.facebook.com/groups/VLF.ULF.ELF


-- 
Jean-Marie Polard
F5VLB

http://www.polard.fr/


jdow
 

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, f5vlb.jmp@... wrote:
have a look here also : https://www.facebook.com/groups/VLF.ULF.ELF


f5vlb.jmp@...
 

have a look here also : https://www.facebook.com/groups/VLF.ULF.ELF


Paul Cianciolo
 

Hello All,

Several folks have asked about the propagation at VLF frequencies.
Here is a video I made about a specific VLF propagation mechanism.
Take a look at the Sunrise and Sunset effect at 40.750 KHz
Using the AirSpy Discovery, the "LIL" Low Impedance Loop, SDR Console V#3 and Radio SkyPipe recorder.
https://youtu.be/7-UJ3bG2Rl4

W1VLF