Peter,
oh yes, propagational effects are also present on 9
kHz. Sunrise and sunset produce rapid changes or dips. There is also a
slower diurnal pattern during the day, depending on the phasing
between groundwave vs ionospheric components and thus on
distance. According to several observations, there seems to be a
midday maximum at about 400 km, but a minimum at 200 km.
In the lower kHz range (3 to 14 kHz), there
are sometimes remarkable selective fading effects impressed
on the QRN spectrum, for example on Haldór's wideband
spectrograms
This effect seems to be most prominent when
tropospheric QRN sources are more or less localized in a small region,
so most of the spherics are at similar distance.
Best 73,
Markus (DF6NM)
Sent: Saturday, March 24, 2012 12:39 AM
Subject: Re: LF: Now using Mini Whip here on 8970 Hz in JO33kh,
Appingedam
Hi Hi.
I started listening on VLF because I did build a SID
detector.
Later on we meet. We learned about programming SL.
as a SID detector.
In advice of you, I will QSY to GQD on 22.1. Its also
strong here as you can see in the spectrum overview here:
I wonder is SID's does have effect on 9 Khz
signals.
Does sunset and sunruse have also effect on 9 Khz
signals like it has ons the signals between 19 and 24 Khz ?
Learning day by day !
73's Peter - PA1SDB'
