From: "James Cowburn" <james.cowburn@virgin.net>
To: <rsgb_lf_group@blacksheep.org>
References: <BFF6723B062BFF40B4B7A6CF670160B4040FEB50@argos2.clb.tcfr.thales>, <003001cb1eba$b04ba950$4001a8c0@lark>, <AANLkTileY5Sk4URCfce7Xv3S8lkjd4t65QVMocyiYOcY@mail.gmail.com> <4C36F33E.9843.7F2EB54@mike.dennison.ntlworld.com>
Date: Fri, 9 Jul 2010 11:19:32 +0100
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Subject: LF: RE: TA DX on 137kHz/9kHz?
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Wright Brothers
Travelling on trains faster than 30mph
Falling off the end of the world
Walking on the moon

G7NKS getting > 1000km on 500KHz!!

All thought to be impossible but done

XYL @ G7NKS curtailing her clothes budget....?  err ok well so some
things...



=20
=20
=20
With best regards
=20
=20
Jim  G7NKS
=20
=20
Dr. James Cowburn
E james.cowburn@virgin.net
=20
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-----Original Message-----
From: owner-rsgb_lf_group@blacksheep.org
[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Mike Dennison
Sent: 09 July 2010 10:01
To: rsgb_lf_group@blacksheep.org
Subject: LF: TA DX on 137kHz/9kHz?

Warren is right to say that transatlantic QSOs on 137kHz have been=20
rare but he underestimates the facts.

There have been around ten two-way contacts between Eu and NA, all=20
with VE1 or VO stations. Successful UK stations include G0MRF, G3LDO,=
=20
G3AQC, M0BMU and myself. I think G3YXM may also have made a two-way.=
=20
M0BMU has made it using several different modes, including WOLF. To=20
this list, I believe you can add DF6NM and CT1DRP. At least 250mW ERP=
=20
has been required.

Several others in G, as well as stations in F, DL and PA have made it=
=20
one way to the USA (most Ws are not licensed for two-way contacts). I=
=20
am sure I have missed out some people here.

One of the main difficulties of a two-way LF QSO is having good=20
propagation for long enough - several hours. This is made much worse=
=20
on 9kHz by the need for extremely large bit lengths. Even if the path=
=20
losses could be overcome, a new QSO protocol would have to be=20
invented.

Good luck to the experimenters - just because it seems impossible,=20
there's no reason to stop trying.

Mike, G3XDV
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

> Well lets start by looking at the success of stations on 137kHz -
> pretty dismal actually.
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> I know that there was a TA contact on 137 10 or more years ago betwe=
en
> the late Larry Kayser VA1LK and G0MRF but I don't think there's been
> anything since.   My experimental station WD2XGJ is copied nearly 10=
0%
> of the time in Europe, I run 4W ERP and QRSS 60 though QRSS 3 has ma=
de
> 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 ha=
ve
> a perfect "O" copy of "AQC" in QRSS 60 from Laurie.
>=20
> 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 !
>=20
> For 9kHz you would need both stations using kite or balloon supporte=
d
> aerials - there the hold up will be with the aviation authorities.
>=20
> Somebody should definitely go for it, but I wouldn't underestimate=
 the
> difficulties!
>=20
> 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!)
>=20
> --=20
> 73 Warren K2ORS
>                 WD2XGJ
>                 WD2XSH/23
>                 WE2XEB/2
>                 WE2XGR/1
>=20
>=20
>=20
>=20
> On Thu, Jul 8, 2010 at 12:26 PM, Alan Melia
> <alan.melia@btinternet.com> 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 sunse=
t
> in Canada or just before dawn in Europe. That is not much of a > hel=
p
> as flying kites at those times is not really feasible =A0:-)) =A0 Th=
inking
> > 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 winte=
r
> (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 previo=
us
> tests. Its 4 times further that suggest 16 times the ERP or >
> "capability" of the system. Hopefully if the VLF effect helps it mig=
ht
> 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 Sch=E4fer"
> <Stefan.Schaefer@iup.uni-heidelberg.de> > To:
> <rsgb_lf_group@blacksheep.org> > 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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