At the time I made the original measurements my instrumentation (HP-8510) had a
low frequency limit of 45 MHz and I had a space limitation. Consequently, I
couldn't measure at the frequencies where ladderine is commonly used. Because
of the remarkable march of technology, I now have both N2PK and DG8SAQ Vector
Network Analyzers that can measure at lower frequencies with commensurate
accuracy. I also discovered that I have a spool of ladderline I acquired years
ago at a swap meet when I still thought using it was a good idea.
So, when I get around to it and have a balun, or two, useful at a MHz or so, I
will measure this stuff. I have determined that it uses 18 AWG Copperweld but
don't (and maybe never will) know how thick the copper is.
Wes, N7WS
On 2/5/2017 11:32 PM, Dan Maguire via TowerTalk wrote:
As a follow-up to what Wes said, his measurement results were used to derive
the Zo, VF, and loss data for Wireman ladder line as contained in
TLDetails/Zplots/AutoEZ/SimSmith and a few other places.
Wireman #551 (18awg solid CCS): Nom Zo=400, nom VF=0.902
Wireman #552 (16awg stranded CCS): Nom Zo=380, nom VF=0.918
Wireman #553 (18awg stranded CCS): Nom Zo=395, nom VF=0.902
Wireman #554 (14awg stranded CCS): Nom Zo=360, nom VF=0.930
Values are not *exactly* what Wes reported due to some additional data analysis.
All of the above software packages adjust Zo and VF for frequency. As
frequency gets lower |Zo| goes up and VF goes down. This applies to all
transmission lines and Jim Brown has verified that with various measurements.
Dan, AC6LA
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