[Elecraft] The "Kinda Random Antenna"

[Barry]

My points when I started this were open wire can help in a bad 
situation. I was not using 130' antenna, but one that was only 33'. And 
I was able to get out. Which leads to my second point. Some of us live 
in areas or on property that is not best suited for HF antennas, but so 
what. With a little thought, a bad situation can be made to work out 
pretty well. And lastly, throw something up and try it; you never know 
just what might happen.

As an aside, I was surprised that I could load a 33' on 160, and more 
surprised when I was actually able to get out of my state; I live in 
Maryland. Morocco and Mexico where a shock. And, I will admit you can do 
things during contests that are nearly impossible at other times.

Something to consider. Open wire was around almost as far back as 
Marconi, and maybe he used it. It has little loss even at high SWR, far, 
far less than coax in the extreme. In the olden days, no one really 
worried about SWR losses. Open wire was the common transmission line. 
Antenna tuners weren't really around, either.The trick that was done in 
those times was to have your final amplifier's tank circuit tune to the 
output frequency and act as the antenna coupler. In fact, the commercial 
station on Montauk Point at the tip of Long Island used to use rhombic 
antennas pointed toward Europe. The station engineer told me that the 
SWR was around 14:1 and he didn't worry too much about it as the loss on 
the line to his antenna was about 1 db and the a swinging link took care 
of the match.

As hams in today's world, there are a few things that can be done to get 
out on HF. Putting up the biggest antenna with the most gain is at the 
top of the list. But, not everyone has the ability to do as some of my 
friends like W3LPL, for instance, are able to do. But, there is one 
thing that many hams overlook, cut the loss from your radio to the 
antenna. That means use the transmission line that has the least loss 
for the situation and make sure you can operate your antenna tuner, if 
needed, in a range that has its losses at a minimum.

Do not worry about resonance. Most of us use antennas that if they were 
resonant wouldn't reflect 50 Ohms anyway.

73,
Barry
K3NDM


------ Original Message ------
From: "Ron D'Eau Claire" <ron at cobi.biz>
To: elecraft at mailman.qth.net
Sent: 1/31/2017 11:53:49 AM
Subject: Re: [Elecraft] The "Kinda Random Antenna"

>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.
>
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