[Fwd: LF: LF LOOP INFO]

[Andre' Kesteloot]

Toni Bärtschi wrote:

> >From HB9ASB, JN36pt
>
> For those group members who understand german, there is book called "Rahmenantennen" from Ben Peters (Wilhelm Herbst Verlag, Köln,
> ISBN 3-923 925-47-6) It contains articles and patents about loop antennas from 1907 to 1987. There are also a lot of references. Even the craziest ideas are documented, so you will certainly not reinvent the wheel, hi.
>
> 73 de Toni
>
> tracey gardner wrote:
>
> > There seems to be a lot of the re-inventing the wheel syndrome
> > when it comes to the use of loops for LF reception.
> >
> > Long and Medium Wave listeners have been using loops for decades and
> > have probably evolved the tuned loop as far as it can go?
> >
> > I'd suggest picking the brains of the ardent LW/MW listeners as we
> > amateurs are mere babes in arms when it comes to the use of loops.
> >
> > I understand that "The Medium Wave Circle" offers a re-print service
> > and has a number of articles on loops.
> >
> > Regards
> >
> > Tracey G5VU
> >
> > =======================================================================
> >
> > on 30 Nov 98, rsgb_lf_group@blacksheep.org wrote...
> >
> > >
> > >> I can pass on some experience from New Zealand.  Computer ribbon is an
> > >> attractive way to make a "coil" by connecting wire1 end2 to wire2 end1,
> > >> and so on ... and there could even be tapped turns.  However, actual
> > >> testing has shown that computer ribbon has quite high capacitance per
> > >> unit length, and if nothing else this limits tuning range, but it also
> > >> lowers Q.
> > >
> > >I have made an LF receiving loop with a square configuration, one
> > >metre per side. I used 14 wires of a section of ribbon cable and used
> > >one separate turn for coupling to the receiver.
> > >The main loop is tuned with a 1000pf air-space capacitor.
> > >
> > >> The basic test of a frame receiving loop for LF DXing is that it can
> > >> distinguish QRN as the main component of background noise.  If it can't
> > >> then you are probably missing some weak signals ....
> > >
> > >Very true. I used a MAR amplifier as described by John, G4GVC, in
> > >'The LF Experimenter's Source Book' to improve the sensitivity.
> > >
> > >
> > >> So the computer ribbon is expedient, but unlikely to be a high
> > >> performer.  I was hoping to stuff the ribbon inside plastic conduit
> > >> pipe, and have a weatherproof frame loop for mounting outside, but it
> > >> has not worked out that way.
> > >
> > >I used the plastic conduit construction and it kept the wires dry
> > >even in this very wet year we have had in the UK. The tuning
> > >capacitor is mounted outside the conduit and wrapped in polythene.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >--
> > >Regards, Peter, G3LDO
> > >
> > ><g3ldo@zetnet.co.uk>
> > >
> > >
> > >
>