Hello Carter,
Why not eliminate the balanced line near the house?
Install a 4:1 current balun on the balanced line well away from the house, and
connect from the balun to your tuner with 50 ohm coax. Bring it thru the wall
and have nothing radiating in the shack.
A line isolator can also be installed right before the Eagle.
I sit under a fan dipole and have no issues with 100 watts portable.
Naturally, a good single point ground with a short low impedance ground
connection is desirable, but I operate at the beach from the second floor
without it.
Leave the RF outside.
73,
Mike
W2AJI
Sent from my iPhone
> On May 14, 2014, at 6:43 PM, "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de> wrote:
>
> Actually James hit on an important point here: feedline length.
>
> Actually it has nothing to do with impedance matching but everything to do
> with the behavior of common mode current on the feedline.
> Unlike the transmitted RF current which is the same for the entirelength of
> the feedline, common mode current is not the same at all places along the
> feedline. It varies constantly.
> It is worst a half wavelength away from the feedpoint and minimum a quarter
> wavelength away from the feedpoint.
> You must consider the vf of the feedline (but not its transmission line vf,
> rather the vf of the individual wires - which is probably about .97 our
> .98).
>
> G3TXQ reports measured data on this on his web site at the bottom of his
> page on RF chokes:
> http://www.karinya.net/g3txq/chokes/
>
> You didn't specify which band(s) the problem is on.
> A quick try would be to insert 1/8 wavelength of additional feedline between
> the existing feedline and the JV Matchbox.
> Of course it you are on 80m, this is not going to be an option.
>
> I still suggest the dual RF choke as per my previous email.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of TTMaven
>
> Have you tried different lengths of feed line - window line and coax,
> respectively? I won't recite all the reasons here, but you know how various
> lengths of feed line matter to impedance matching, etc.
>
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