Hi Joe my guess is at extreme daytime range you are getting D-layer returns
at this time of year. The D-layer is quite highly ionised in summer daytime,
and you are way out of ground wave range at that power. LF signals usually
have enough strength to survive one reflection in daytime at grazing
incidence (minimum pennetration of the absorbing layer) There is a
characteristic "Dome" shape to the signal plot in daytime with a peak when
the sun is overhead at mid-path.
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Thursday, July 31, 2008 4:05 PM
Subject: Re: LF: 187.375khz
> Hi Henny, LF Group.
> The beacon was switched off at 0230 to prevent damage from
> an electrical storm. It will resume operation this evening.
> Thank-you for monitoring my signals, Henny and others.
> Do your receptions coincide with off-times for the high
> power broadcast stations?
> Local reception tests were conducted earlier this month and it was
> noted that the beacon was audible at distances of 600 km in the
> daytime over a water path at 47 north. At higher latitudes
> (about 50-55N) Iceland on 189 kHz was quite strong and prevented
> aural reception of the beacon. What I found amazing was that
> this persisted even during the daytime. Shouldn't E-layer absorption
> preclude transatlantic LF propagation at high noon? There must be
> something else at play?!
> Joe VO1NA
> On Thu, 31 Jul 2008, henny van elst wrote:
> > hi joe,
> > this time nothing seen,
> > best 73s
> > henny pa3cpm.