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[TowerTalk] Coax question

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Subject: [TowerTalk] Coax question
From: (Pete Smith)
Date: Wed, 17 Oct 2001 15:21:10 -0400
My 80-meter lazy-vee parasitic array uses the inductive reactance of the
unused coax feedlines, whose center conductors and shields are floated, to
electrically lengthen the unused dipoles so they act as reflectors.  It
works quite well.

Currently, the feedlines are draped through space from the feedpoints to
the tower at about 60 feet, then down inside the tower to the switchbox at
about the 40-foot level.  For 160M shunt feed reasons, I am contemplating
bringing the feedlines directly to the tower at the switchbox level and
winding each coax feedline into a 12-turn coil roughly 12 inches in
diameter, which would be suspended a foot or so from the tower.  The hope
is that these coils would provide enough reactance at 160 meters (~1000
ohms) to effectively isolate the 80m feedline shields from the tower,
improving the shunt feed situation.  Models seem to indicate this is so.

And the question is ... will coiling the coax in this way cause the
inductive reactance it presents at the dipole feedpoints on 80 meters to
change appreciably? 

73, Pete N4ZR

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