[TowerTalk] bad coax? and EF-240 tuning
Wed, 15 Oct 1997 14:02:14 -0400
I'm having a little trouble getting the elements for my Force-12 EF-240
tuned up properly. I hauled the driver element up the tower yesterday
to check out the resonant frequency, and found two suprises...the
resonant freq was much higher than expected (7.300) , and the SWR was 2:1 at the
So I lowered the element back to ground level, checked it again and the
resonant freq had shifted up by about 50 Khz (sounds okay). But then
I changed feedlines (RG-8X), and the freq was down to 7.115 (closer to expected)
but the SWR is still around 2:1.
The original coax is 9913F (about 150-160 feet), its brand new, never
been on the air or outside. The second coax is some old RG-8X that is
about 40-50 feet long.
A couple questions:
1) Should the 40 Meter element have a dip of 1:1????? If so I've got some
work to do on that element.
2) How do I figure out if my coax is bad??? Would a bad connector installation
cause what I'm seeing (maybe the dielectric got too warm and the center conductor
migrated too close to the shield?)
Thanks & 73's
--Lee - KT4ZX
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