In my experience the choke at the loop end of the feedline (before the
transformer) is essential - the signal levels coming from the loop are so
low that it doesn't take much shield pickup to fill in the nulls in the
pattern. I use the ON4UN double-choke setup and it seems to work very well.
73, Pete N4ZR
At 10:19 AM 10/14/2008, Joe Subich, W4TV wrote:
> > Coupling to "something" is the strongest possibility. It can
> > be the radials as well as the radiator of the Inv-L. I would
> > recommend a choke at the loop connection.
>
>I would also suspect re-radiation from the inverted L -
>particularly since directivity falls apart as the frequency
>moves closer to the "resonant" frequency of the inverted L.
>The vertical wire on the L should be "floated" in receive to
>see if that is a factor.
>
>73,
>
> ... Joe, W4TV
>
>
>
>
> > -----Original Message-----
> > From: antennaware-bounces@contesting.com
> > [mailto:antennaware-bounces@contesting.com] On Behalf Of K9AY
> > Sent: Tuesday, October 14, 2008 9:58 AM
> > To: RFD; antennaware@contesting.com; topband@contesting.com
> > Subject: Re: [Antennaware] New K9AY Observations
> >
> >
> > Comments interspersed...
> >
> > > I notice that directivity of the loops on the BC band from below
> > > 1600khz is dramatic to say the least.
> >
> > That's a good start. Things are not a total mess!
> >
> > > On 160M however directivity of the loops is not dramatic at
> > all. Many
> > > signals are the same strength on all loops..... So I am concluding
> > > that the tower and the Inv L are screwing up the loops on 160M.? ...
> > > Also I am not yet using a common mode choke on the RG6 feedline of
> > > the loops.
> >
> > > 73 Frank VO1HP
> >
> > Coupling to "something" is the strongest possibility. It can
> > be the radials
> > as well as the radiator of the Inv-L. I would recommend a
> > choke at the loop
> > connection. Be sure the control wires are choked, too. These
> > wires may be
> > the culprit, or perhaps an accomplice that aids coupling to
> > the radials. The
> > Array Solutions loop box has instructions for separating the
> > antenna and
> > feedline grounds -- this may help as well.
> >
> > 73, Gary
> > K9AY
> >
> > _______________________________________________
> > Antennaware mailing list
> > Antennaware@contesting.com
> > http://lists.contesting.com/mailman/listinfo/antennaware
>
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