Warren is right to say that transatlantic QSOs on 137kHz have been
rare but he underestimates the facts.
There have been around ten two-way contacts between Eu and NA, all
with VE1 or VO stations. Successful UK stations include G0MRF, G3LDO,
G3AQC, M0BMU and myself. I think G3YXM may also have made a two-way.
M0BMU has made it using several different modes, including WOLF. To
this list, I believe you can add DF6NM and CT1DRP. At least 250mW ERP
has been required.
Several others in G, as well as stations in F, DL and PA have made it
one way to the USA (most Ws are not licensed for two-way contacts). I
am sure I have missed out some people here.
One of the main difficulties of a two-way LF QSO is having good
propagation for long enough - several hours. This is made much worse
on 9kHz by the need for extremely large bit lengths. Even if the path
losses could be overcome, a new QSO protocol would have to be
invented.
Good luck to the experimenters - just because it seems impossible,
there's no reason to stop trying.
Mike, G3XDV
==========
> Well lets start by looking at the success of stations on 137kHz -
> pretty dismal actually.
>
> I know that there was a TA contact on 137 10 or more years ago between
> the late Larry Kayser VA1LK and G0MRF but I don't think there's been
> anything since. My experimental station WD2XGJ is copied nearly 100%
> of the time in Europe, I run 4W ERP and QRSS 60 though QRSS 3 has made
> it across and I believe that F1AFJ has reported that my signal is
> audible on quiet winter nights under good conditions. I have only
> copied 1 station from across the pond - the late G3AQC on 137 - I have
> a perfect "O" copy of "AQC" in QRSS 60 from Laurie.
>
> Very few stations put out a decent signal and the 1w ERP limit in EU
> is just too low for reliable copy, combine that with the fact that
> many amateurs in the UK aren't even sure if they should be making
> foreign QSOs and the result is nada zilch zero !
>
> For 9kHz you would need both stations using kite or balloon supported
> aerials - there the hold up will be with the aviation authorities.
>
> Somebody should definitely go for it, but I wouldn't underestimate the
> difficulties!
>
> I suggest we start a pool everybody kicks in a few
> dollars/pounds/euros for a prize for the 1st stations to make a
> verifiable TA contact (I will personally kick in some money and I'm
> not too concerned about having to pay out!)
>
> --
> 73 Warren K2ORS
> WD2XGJ
> WD2XSH/23
> WE2XEB/2
> WE2XGR/1
>
>
>
>
> On Thu, Jul 8, 2010 at 12:26 PM, Alan Melia
> <[email protected]> wrote: > Hi Stefan, Mmmm I suppose I put
> my head right into the noose there :-)) > > I think this is a
> difficult one. I am sure the ideal time would be just > before sunset
> in Canada or just before dawn in Europe. That is not much of a > help
> as flying kites at those times is not really feasible :-)) Thinking
> > more generally I would say the best time in a daylight path might be
> mid-day > at mid path.....but that is only a "gut feeling". But in
> daytime, summer > might be better for daytime propagation than winter
> (not allowing for > seasonal noise variation) ......I'm ducking and
> diving and hedging by bets > :-)) > > It could be Paul's waveguide
> propagation equations would give helpful > answers. If only to
> calculate the approximate signal levels to compare with > the previous
> tests. Its 4 times further that suggest 16 times the ERP or >
> "capability" of the system. Hopefully if the VLF effect helps it might
> only > need be nearer to 6 to 8dB. There may also be a limitation to
> how narrow a > bandwidth you can use on reception on a path of this
> length. > > I am watching with interest, this is quite a new area, and
> you can't beat > experimentation. If that don't fit the theory.....
> you have to devise a new > theory ....not junk the measurements,
> because you cant argue with > measurement. > > Best Wishes > Alan
> G3NYK > > ----- Original Message ----- > From: "Stefan Schäfer"
> <[email protected]> > To:
> <[email protected]> > Sent: Thursday, July 08, 2010 1:23 PM
> > Subject: VLF: TA DX on the dreamers band? > > >> Alan, >> >> Which
> time (UTC) would be your recommendation for trying a transatlantic >>
> DX reception on 9 kHz, say to canada? >> Any ideas? >> >> Other
> experts are asked as well here! >> >> >> > > >
>
>
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