[Fwd: LF: Receiving antennas at LF]

Frank Gentges gentges@itd.nrl.navy.mil
Thu, 4 Feb 1999 15:00:48 +0000 (GMT)

Hi, What we need is an experiment that compares a good "at the noise level" 
active efield probe, "at the noise level" active loop and a "really big" 
receiving antenna against a very weak (Lowfer?) signal.  Annapolis should
help us devise such an experiment.  The common wisdom in the Lowdown is that
the active antennas will match the performance of a big antenna short of 1000
feet. The brits on the other hand, seem to be stressing apeture.  Who is 


On Wed, 3 Feb 1999, Andre' Kesteloot wrote:

> Dave Sergeant wrote:
> > >From Dave Sergeant G3YMC
> >
> > I note with interest the comments from Mike G3XDV and Peter G3LDO on the
> > performance of large wire receiving antennas.  I think what they say is
> > true.  I can often hear signals on my long wire (only 60 ft of it) which
> > are not audible on my loop, and this seems to be true particularly for the
> > more distant stations.  Apart from LX1PD who is always strong, most of the
> > other european stations here are very weak or inaudible on the loop, while
> > quite copyable on the long wire.  My main limitation of using the long wire
> > is that it picks up far more local noise and QRN and is virtually unusable
> > in the evening.  It is currently untuned, but I suspect if I did tune it it
> > would just make the noise pick up problem much worse.
> >
> > Even so, I have yet to hear OH1TN on either of my antennas, and I suspect
> > this proves that a properly resonated high and very long wire does indeed
> > outperform other antennas on the band.  I do not however have the real
> > estate for such an antenna!
> >
> > It is difficult to know exactly how the receivers worked at the USA site
> > the other weekend, and how the band sounded compared with what we are
> > accustomed to hear over in the UK, but I perhaps have the impression that
> > their performance and that of the antennas were a bit down.  The fact that
> > Andre didn't think Loran too much of a problem may well indicate something
> > in this respect.  A future listening experiment with 200-300 ft long wires
> > may well show a rather different story.
> >
> > Cheers Dave G3YMC