[TowerTalk] K9YC Choke Cookbook Question

[Wes Stewart]

If you follow this link http://k6mhe.com/n7ws/Ladder_Line.pdf to my paper and 
look at Table 1, it gives the measured values of four different Wireman P/Ns.

Note that these are 50 MHz values and transmission line Zo and Vp are anything 
but constant at lower frequencies.  Likewise, these particular lines use 
copper-clad steel conductors that "misbehave" at lower frequencies so Eq 4 
somewhat falls apart when the conductors do not have a well-developed skin 
effect. I mentioned this in the paper but did not account for it in the equation.

Wes  N7WS

  On 2/5/2017 5:11 PM, Hardy Landskov wrote:
> Hi Jim and all,
> The email below reminds me of a problem I had some years ago with "450 ohm
> window line". Nothing seemed to work. I then found an article that explained
> how to measure the Zo of coax/ladder line. I measured a piece of window line
> and it was 374 ohms! I found out in the archives that W8JI had measured 377
> ohms with a piece of window line. We exchanged emails and he was elated that
> I had verified his results.
> Here you have two different sets of equipments, two different runs of ladder
> line, and different times. I was very happy myself. I have an HP8753B so it
> was no problem to run through the numbers. It was a very eye opening
> exercise!!
> Bottom line: Use 375 ohms for matching tuners and other things when using
> this line.
> 73 Hardy N7RT/4
>