Hi Roelof, very interesting! I am always hesitant about extrapolating the 
results I have for 139kHz up the frequency range. It would seem from your 
comments that the attenuation may be higher (TF & SM are single hop) at higher 
frequencies. This is interesting in the way the ideas fit with 500kHz DX. I 
guess maybe I should expect this....but I much prefer solid experimental data 
:-))
"Never mind the theory, show me the measurements" :-))

Thanks and Best Wishes
Alan
G3NYK

--- On Fri, 9/3/12, Roelof Bakker <[email protected]> wrote:

> From: Roelof Bakker <[email protected]>
> Subject: Re: LF: Big solar flare - major geomagnetic storms to follow
> To: [email protected]
> Date: Friday, 9 March, 2012, 11:29
> Hello Alan,
> 
> In the NDB band the effects were rather dramatic.
> Propagation from Scandinavia was very poor/non-existant.
> Even close by stations e.g. from Poland were much weaker
> than usual.
> 
> One of my propagation markers is NDB VM-375 from Iceland.
> It is very rare not to hear it, but yesterday evening it was
> completely gone.
> At 04:00 UTC this morning, I could only spot a weak trace.
> 
> The band noise was also very low, which indicates that
> distant QRN was not propagated very well!
> 
> All in all quite interesting!
> 
> 73,
> Roelof, pa0rdt
> 
>