Here's a thread on zipcord loss from years ago:
http://elecraft.365791.n2.nabble.com/What-your-mother-didn-t-tell-you-about-transmission-lines-td6780383.html
This is a real world result I observed:
"About 10 years ago ET3PMW was attempting to get on the low bands and only
had zip cord available
0) To: Elecraft Mailing List
Subject: Re: [Elecraft] Off topic feedline question
Thanks to all of you for your responses. My need for a lower impedance
parallel line is not so much a matter of loss but to minimize the impedance
transformer effect a 25’ window line (400 ohm) has when terminated in a
You are mistaken. 25' of ladderline is only about a tenth of a wavelength and
does not invert impedance. I suggest you download Dan's TLDetails program:
http://ac6la.com/tldetails1.html and play with it. Put in what you think, or
have measured, the feedpoint Z is then select one of the Wireman
raft Mailing List
Subject: [Elecraft] Off topic feedline question
My 80M antenna is a low, loaded dipole fed with balanced window line. As the
center impedance is low the high impedance window line tries to invert the
impedance to a much higher value. The feedline is only 25' long and terminates
survive in
weather and sunlight and its RF voltage breakdown rating.
The two data references were quite helpful. Thanks again!
Michael Blake
k9...@mac.com
From: Michael Blake
Sent: Tuesday, November 7, 2017 9:12 AM
To: Elecraft Mailing List
Subject: [Elecraft] Off topic feedline question
My 80M
Yes, googling "zip cord hf loss" yields the classic QST article:
http://www.w1npp.org/events/2010/2010-f~1/antennas/wire/790303~1.PDF
among others. Here are measurements made with a Rigexpert AA-600;
http://owenduffy.net/blog/?p=327
Bob NW8L
On Tue, 7 Nov 2017, Michael Blake wrote:
The ques
I didn't study this site too deeply, but KP4MD has the most appropriate
characteristics on her page, here, http://www.qsl.net/kp4md/zipcord.htm.
You might also look at Owen Duffy's pages. His transmission line calculator is
great. I think the last entry for zip 105 is zip cord, but you should ema
My 80M antenna is a low, loaded dipole fed with balanced window line. As the
center impedance is low the high impedance window line tries to invert the
impedance to a much higher value. The feedline is only 25' long and terminates
in a 1:1 balun which is then connected to a remote autotuner
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