[TenTec] Wet ladderline

[Steve Hunt]

Jim,

Thanks for pointing me in the direction of Zplots - I'd not appreciated 
what it can do, although I'm a big fan of AC6LA's TLD software.

I just downloaded Zplots and ran open and short S11 tests on the line. I 
plugged the values Zplots gave me for Zo, Vf, K0, K1 and K2 into TLD, 
however it then predicts losses very different from my measured losses. 
But, interestingly, if I use TLD's default parameters for Wireman 551 it 
predicts losses very close to what I measure!

It's not clear to me yet why Zplots would give me line parameters so 
different from TLD's parameters for Wireman 551.

I need to explore this some more because if Zplots can produce 
believable results it would save me a lot of number crunching :)

Steve G3TXQ


On 09/08/2013 16:55, Jim Brown wrote:
> Another way to get transmission line parameters from VNA or VIA 
> measurements is to measure S11 with the far end open and shorted, or 
> to measure S21 and export the data to AC6LA's Zplots spreadsheet.  
> I've used this with good results for 50 and 75 ohm coax, and for 
> closely spaced parallel wire line in the range of 90 ohms.
>
> Although S21 data and S11 data should produce the same results, Dan 
> told me that users of his spreadsheet reported more consistent results 
> when S11 data sets were used.  I've tried both, and agree that the S11 
> data sets are the better way.
>
> There's a lot of useful stuff on Dan's website. http://www.ac6la.com/
>
> 73, Jim K9YC
>
> On 8/8/2013 2:59 PM, Steve Hunt wrote:
>> I managed to find time today to produce a web page on my measurements.
>>
>> For anyone interested:
>> http://www.karinya.net/g3txq/wet_ll/
>
>
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