[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
right?
Frank
On Wed, 3 Feb 1999, Andre' Kesteloot wrote:
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> 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
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