[Elecraft] The "Kinda Random Antenna"

[Wes Stewart]

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:elecraft-bounces at mailman.qth.net] On Behalf Of Wes
> Stewart
> Sent: Tuesday, January 31, 2017 5:07 AM
> To: elecraft at mailman.qth.net
> 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.