I would agree Alan that on the longer hauls I still see a more rapid fade pattern but not the couple of mins typical of the shorter hop stuff -
- I sort of got used to "20 mins" for 137Khz on the Transpolar and Trans Siberian paths into China from Eu, but it was a little more than "5 mins" at 500Khz - that sort of aligns on what I saw at sea on the Antarctic/South Atlantic paths on 500 back to Portishead path back long long ago, and what I have heard from here and Fiji into Oz and NZ - but I also recall the fades became more vertical and shorter during the more disturbed periods - again this way very dependant on the path profile and where it and what it crossed on the Rhum line geomag and whether it was North/South East West - again cutting across the "lines" was far more problematic.
I still scratch my head to see the MUF map of the world and how it looks more like a complicated barometric pressure map with depressions and High pressure areas :-)
What I would do is not to discount the long periods out of hand at 500 - I have a tingly feeling that dot 30 is as slow as I would go but Ive been proved wrong countless times :-)
What I do know is to date that bar Japan to Alaska (apart from Canada/USA) no signals have reached the levels that my old CW ears could decode, and truthfully I dont think they would ever get to that level at our ERP levels and lack of the salty stuff.
Mind you I would love to set up an MF station here on Maui - Ive already picked my spot and the tower I would steal (Junction of Lahaina/Kihei road at South Kihei).
Im trying to twist a certain arm to install MF on our expedition ship, but we dont have a lot of space for the normal type of array Im used to. We will see
> From: [email protected]
> To: [email protected]
> Date: Tue, 12 Feb 2013 01:09:31 +0000
> Subject: LF: Re: Considerations about wide DX experiments on 630m and tonites QRSS-60
> Hi Stefan I think that maybe the right approach. I think you may find that
> the "perceived wisdom" on fading rate v QRSS speed is based on relatively
> short paths. I suspect it may well be very different at real DX range, that
> is several hops.......>6000km. There obviously is some sort of a problem
> because the wavelength is much shorter than 136kHz so the phase changes more
> rapidly with ionisation and "apparent refection height" but you need two
> "modes" of nearly equal strength to get extinction. This may not be so
> prevalent at long ranges on 470kHz. The experiment will be very interesting
> if you can start to leave traces on distant grabbers.
> ----- Original Message -----
> From: "Stefan Schäfer" <[email protected]
> To: <[email protected]
>; "Vasily Savchenko" <[email protected]
> "Garry and Linda Hess" <[email protected]
>; "Douglas D. Williams"
> <[email protected]
>; "Andy - KU4XR" <[email protected]
>; "Edgar J Twining"
> <[email protected]
> Sent: Monday, February 11, 2013 10:57 PM
> Subject: LF: Considerations about wide DX experiments on 630m and tonites
> > MF !!!!!!!!!!!!!!!!!!!!!!! ;-)
> > Edgar in Tasmania was recently asking if i have some plans about DX
> > experiments on 630m. Well that is a path of > 16000 km. However we do not
> > have real experience if that is easier than 2200m or rather impossible.
> > At least i know that there was not even a single decode by UA0SNV in my MF
> > WSPR and QRSS tests so far, while it is no problem on LF (OK my MF signal
> > is weaker than my LF signal). Thus i would guess that it is much harder to
> > get some traces of a signal on 630m. We will try anyway!
> > I'm starting to run a QRSS-60 transmission on 476.172 kHz (+- a few Hz)
> > for the night. Maybe someone across the pond will catch something. We, or
> > at least i still have no experience about the QSB problem on very slow
> > QRSS transmissions on MF. It would be interesting to see a spectrogram.
> > On air in a few minutes.
> > 73, Stefan/DK7FC
> > PS: No, not only beacon transmissions, i've just had a > 1 hour long CW
> > QSO with PA0LCE and DK6SX/p! Also contacts to OK2BVG and S57A.