[Lf] [Fwd: LF: polarization of small loops]

[Andre Kesteloot]

jannsen wrote:

> Rik Strobbe schrieb:
> > Dear LF group,
> >
> > I have been looking for some information about the polarization of small
> > loops, but no success.
> >
> > For full-size loops things are quite clear, a loop can be polarized
> > horizontal or vertical depending on the feeding point.
> >
> > What about small loops ?
> > I found several descriptions of small transmitting loops close to ground
> > and there loops were fed at different places (center horizontal side, at
> > the edges). Polarization seems to be vertical in all cases.
> > And what about a small loop is free space ? Current distribution is uniform
> > over the entire loop, regardless of the feeding point. So one would expect
> > always the same polarization (but which one ?). Unless also the voltage
> > distribution plays a role.
> >
> > Anyone who can point me to the right theory and/or has experience with
> > feeding small loops at different points ?
> >
> > Thanks in advance,
> >
> > Rik   ON7YD
> >
> >
> Hi Rik es all,
>
> the following may confuse the loop scene still more:
>
> I have a loop 70m long, 12m high and 2m above ground with two windings,
> fed at the lower E (east) edge.
> some weeks ago I made a field strength test L-aerial (17m mast and 340m
> longwire 17m to 9m up) contra loop.
> Geri/DK8KW measured the strength using his MV62.
> the loop is erected N/E. DK8KW is located S from here.
> result: no difference btwn the aerials as Geri reported (both 20uV/m).
> so can one say the (my) loop polarizes vertical (non directional)
> if used as TX-aerial?
>
> vv. used as RX-antennas loop to L-antenna was -63dBu to -50dBu (indicated by a
> RYCOM-rx) receiving DK8KW.
>
> receiving Reino/OH1TN (nearly E) RYCOM indicates no
> difference btwn the two antennas.
>
> but Reino does not hear me if I do use the loop as TX-aerial.
> with the L-aerial conn to the TX Reino gives me regular RST 569.
>
> in abt three weeks I will go to the bottom of it.
> I will perform tests in QRSS mode during
> afternoons on 136.0kHz for the purpose of field strength measurements.
> distance to the aerials: on average seven km (3xlambda).
> transmitter power output will be 20 Watt, 130 Watt and 800 Watt.
> Aerials: inv. L-aerial and TX-LOOP.
>
> the test will last several weeks. I cant make any schedule.
>
> is the qrg ok? any protests from the bandplaners?
>
> btw. Rik, in ur fine prgr QRS I do miss the possibility keying a
> continuous dash among the text.
>
> regards
> dj8wx/Uwe
>
>
>
> regards
> Uwe/dj8wx
>
>