Joe mentioned:
"Could part of this fluctuation be from propagation?"
Joe and Paul,
For your consideration and (with your permission) my edification have we
seen natural-propagation-related frequency changes on this timescale?
The only generally acknowledged example of substantial propagation-related
frequency changes (from all-natural processes) that I've seen is ~ 20mHz rms
spreading of VLF signals during strong geomagnetic storms*, which might not
even be a 50-second wander (too fast to show up at recent VO1NA signal
integration times), but could even be simultaneous modulation at frequencies
distributed over 20mHz rms (which also would not be visible given recent
TA-signal integration times). Incidentally the magnetic field has been
basically quiet during the TA tests.
So I'm asking Joe's question and adding a bit (driven by longstanding
curiosity): does the experience base include examples of propagation-related
frequency changes (from all-natural processes) on this timescale?
* "Subionospheric VLF measurements..." (W. B. Peter, U. S. Inan - 2005)
Thanks,
Jim AA5BW
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of [email protected]
Sent: Wednesday, May 10, 2017 1:54 PM
To: [email protected]
Subject: Re: LF: NA VLF
Great news, Paul. The frequency is a bit enigmatic. It had always been a
few ppb low since calibration in 2013 but is evidently bouncing above and
below. Could part of this fluctuation be from propagation?
The sigs will continue until the helix sparks or the wx grounds the aerial.
TNX & 73
Joe VO1NA
On Wed, 10 May 2017, Paul Nicholson wrote:
>
> A nice signal from VO1NA overnight 9th/10th. Happy to see the signal
> on the right frequency 8270.007093 Hz and back to 0.06 fT flux
> density.
>
> --
> Paul Nicholson
> --
>
>
|
