A 130' dipole, 60' high on 160 has a feed point Z of ~4.5 -j1200. One hundred
feet of Wireman 553 (typical ladderline) will transform this to ~7.5 +j16 at the
input. The total loss in this "low-loss" line is over 12 dB.
On 1/31/2017 9:53 AM, Ron D'Eau Claire wrote:
The intrinsic higher impedance of ladder line helps reduce the losses
through a lower SWR than typical coax. A center fed wire at least 1/4 wave
long end-to-end on the lowest frequency used (e.g. 130 feet on 160 meters)
and fed with typical 350 to 450 ohm ladder line will show an SWR of 10:1 or
less across the HF spectrum, since a real-world wire will show an impedance
of only 4,000 ohms or so even when it is exactly 1/2 wavelength long.
Feeding the same antenna with 50 ohm coaxial line will result in an SWR
100:1 or greater and so much greater losses.
73, Ron AC7AC
-----Original Message-----
From: Elecraft [mailto:[email protected]] On Behalf Of Wes
Stewart
Sent: Tuesday, January 31, 2017 5:07 AM
To: [email protected]
Subject: Re: [Elecraft] The "Kinda Random Antenna"
Sadly, this is often untrue.
Get Dan's (AC6LA) program at: http://ac6la.com/tldetails1.html and run some
examples.
for more on ladder line see: http://k6mhe.com/n7ws/Ladder_Line.pdf
On 1/30/2017 9:00 PM, Barry wrote:
...I feed it with ladder line which has low loss even at absurdly high
SWRs, and the tuner I use is designed to be used with antennas that
are no where near optimum.
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