In the north of Scotland today we are picking up Spanish radio stations loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John

Down in South Devon the entire Band 2 VHF spectrum has been alive with
foreign broadcasts coming through in sort sharp bursts of up to 10 seconds,
and in some cases longer. They originate from Spain, France, Holland,
Germany and even one from an eastern European sounding language which I am
unable to recognise. They are so strong that the local tranmissionms from
North Hessary Tor are heavily compromised, especially R4 on 92.5. These
conditions are normally associated with low or medium level temperatiure
inversions which allow ducting along the boundaries, but to get such a broad
geographical spread is indeed unsusual.

Derek Hardy




"J.Poyner" wrote in message
...
In the north of Scotland today we are picking up Spanish radio stations
loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John

"J.Poyner" wrote in message
...
In the north of Scotland today we are picking up Spanish radio stations
loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John

There's an ongoing aurora if that has any link to it...?
http://www.dcs.lancs.ac.uk/iono/aurorawatch/

Joe

"Derek Hardy" wrote in message
...

Down in South Devon the entire Band 2 VHF spectrum has been alive with
foreign broadcasts coming through in sort sharp bursts of up to 10
seconds, and in some cases longer. They originate from Spain, France,
Holland, Germany and even one from an eastern European sounding language
which I am unable to recognise. They are so strong that the local
tranmissionms from North Hessary Tor are heavily compromised, especially
R4 on 92.5. These conditions are normally associated with low or medium
level temperatiure inversions which allow ducting along the boundaries,
but to get such a broad geographical spread is indeed unsusual.

Derek Hardy




This I can well believe as a major thunderstorm with a twister appeared here
for close on 2 hours with hail and heavy rain. There was no forecast of this
whatsoever.

Gavin.

"J.Poyner" wrote in message
...
In the north of Scotland today we are picking up Spanish radio stations loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

NASA have issued this aurora alert
http://spaceweather.com/

See;
http://www.sec.noaa.gov/rt_plots/kp_3d.html

HTH,

Cheers, Alastair.

On Mon, 30 May 2005 12:38:23 +0100, "J.Poyner"
wrote:

In the north of Scotland today we are picking up Spanish radio stations loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John


Picked up a Dutch FM station this morning in Coventry.

Martin

JPG wrote:
On Mon, 30 May 2005 12:38:23 +0100, "J.Poyner"
wrote:


In the north of Scotland today we are picking up Spanish radio stations loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John



Picked up a Dutch FM station this morning in Coventry.

Martin



Looking at the radiosonde from Nottingham at 12Z, there was a very
strong inversion. LFC at 792mbs, the equilibrium level at 764mbs and
CIN of -18.


--
Joe
Wolverhampton
175m asl

So you couldn't get OHBC!

J.Poyner wrote:
In the north of Scotland today we are picking up Spanish radio stations loud
and clear around 90Mhz. I know this is usually due to skipping off the
Ionosphere during daylight but there must be some pretty freak conditions
today to be causing this on these frequencies. Anyone know why?

John

This is nothing to do with temperature inversions!!

The cause of this long-distance reception is a phenomenon called Sporadic E.
It mostly occurs from mid-May through to mid-August, though it can occur at
other times of the year.

It happens when part of the E-layer (70 miles or so above the Earth's
surface) becomes ionised and reflect frequencies far in excess of those
normally reflected by the ionosphere.. sometimes in excess of 200Mhz.
You can hear stations (for example) in southern Spain but nothing else
between, as the nearer stations are inside the skip distance.

This phenomenon is not to be confused with tropospheric conditions - it's a
completely different mechanism.

A full explanation of Sporadic E may be found at
http://www.amfmdx.net/propagation/Es.html

Jim, Bournemouth




"Gavin Staples" wrote in message
...

"Derek Hardy" wrote in message
...

Down in South Devon the entire Band 2 VHF spectrum has been alive with
foreign broadcasts coming through in sort sharp bursts of up to 10
seconds, and in some cases longer. They originate from Spain, France,
Holland, Germany and even one from an eastern European sounding language
which I am unable to recognise. They are so strong that the local
tranmissionms from North Hessary Tor are heavily compromised, especially
R4 on 92.5. These conditions are normally associated with low or medium
level temperatiure inversions which allow ducting along the boundaries,
but to get such a broad geographical spread is indeed unsusual.

Derek Hardy




This I can well believe as a major thunderstorm with a twister appeared
here for close on 2 hours with hail and heavy rain. There was no forecast
of this whatsoever.

Gavin.

Jim Smith wrote:

The cause of this long-distance reception is a phenomenon called Sporadic E.
It mostly occurs from mid-May through to mid-August, though it can occur at
other times of the year.

Yes 10 metres opened up for a while, even a few FM signals and
repeaters in the higher reaches of the band. Oddly the other HF bands
seemed to go down for a few hours but seemed better in the evening -
solar activity maybe.