Hi Ken. I dont know but I would think it should be minimal. The "suckout
effect" does seem to be most pronounced with tuned aerials. I likened it to a
GDO effect where a passive tuned circuit absorbs power from an oscillator.
Roelof's mini-whip not being tuned and being a fairly small coupling
capacitance, and so would probably not show the effect. The effect is most
noticable on receiving loops where a tuned T can totally destroy the pattern of
a loop and also injects wideband noise into it. However detuing the "T" removes
the great majority of the problem. I have a dramatic demo of the coupling when
I got a high induced voltage from a nearby lightning srtike which jumped from
the isolated wire end to a earthy point. My indoor tuned loop was "inside" the
inverted "L" profile and the voltage transfered to the 16t loop blew the gate
out of a 2N3819 I use as and impedance converter. I draw the wire out of the
house on nearby storms now !!
Roelof's mini-whip is certainly a very useful addtion to the LF receiving
armoury..... though it is not as simple to use as we might expect.....as shown
by some of the recent messages.
Best Wishes for DX in 2010
Alan G3NYK
--- On Sun, 27/12/09, Ken <[email protected]> wrote:
> From: Ken <[email protected]>
> Subject: Re: AW: LF: Influence of a TX antenna to a small rx antenna
> To: [email protected]
> Date: Sunday, 27 December, 2009, 12:20
> Hello Alan.
> A very interesting paper of yours, is it likely that there
> will be the same
> interaction between a T antenna and the PA0RDT Mini Whip?
>
> 73.
> Ken
> M0KHW
>
>
> ----- Original Message -----
> From: "ALAN MELIA" <[email protected]>
> To: <[email protected]>
> Sent: Sunday, December 27, 2009 11:51 AM
> Subject: Re: AW: LF: Influence of a TX antenna to a small
> rx antenna
>
>
> Hi Stefan I hope it does not give you indigestion :-))
>
> Good luck with it.....all LF sites are different so in
> general require
> different detailed solutions. It seemed generally to be
> sufficient to
> de-tune the unused antenna to reduce the interaction to low
> levels.
>
> Best Wishes for Dx in the New Year
> Alan G3NYK
>
> --- On Sun, 27/12/09, Stefan Schäfer <[email protected]>
> wrote:
>
> > From: Stefan Schäfer <[email protected]>
> > Subject: AW: LF: Influence of a TX antenna to a small
> rx antenna
> > To: [email protected]
> > Date: Sunday, 27 December, 2009, 10:55
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Hi
> > Alan, tnx, i have
> > printed your article and will read it now at
> breakfast
> > ;-)
> >
> >
> >
> > Perhaps
> > I will come back
> > with some questions… J
> >
> >
> >
> > 73,
> > Stefan/DK7FC
> >
> > -----Ursprüngliche
> > Nachricht-----
> >
> > Von:
> > [email protected]
> > [mailto:[email protected]]
> Im Auftrag von ALAN
> > MELIA
> >
> > Gesendet:
> > Sonntag, 27. Dezember
> > 2009 01:32
> >
> > An:
> > [email protected]
> >
> > Betreff: Re:
> > LF: Influence of a TX
> > antenna to a small rx antenna
> >
> >
> >
> >
> >
> >
> >
> >
> > Hi Stephan yes the aerialls will
> > be very close
> > compared with the wavelength so they
> will interact
> > particularly is tuned. We
> > did some measurements ar Finbar's
> location several
> > years ago
> >
> > http://www.alan.melia.btinternet.co.uk/aecouple.htm
> >
> >
> >
> > The interaction was measured on an
> antenna RF
> > bridge, and demonstrates
> > the coupling between two wires.
> >
> >
> >
> > Best Wishes
> >
> > Alan G3NYK
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>
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