Re: K3 SWR Accuracy - reprise
Posted by
Don Wilhelm-4 on
Nov 05, 2009; 12:19am
URL: http://elecraft.85.s1.nabble.com/K3-SWR-Accuracy-reprise-tp3943810p3949289.html
Steve,
Just one clarification - a mismatched length of coax will transform the
impedance, but a perfectly matched line will not.
Since we calibrate things at 50 ohms, if the coax is exactly 50 ohms and
the SWR is 1.0:1, no impedance transformation will exist. But real coax
lines are "nominally" 50 ohms, so the conditions of a perfectly matched
line may not exist even though the meters tell us it is at a particular
point along the line.
73,
Don W3FPR
Steve Ellington wrote:
> The first statement is correct. Length of coax will transform impedance and
> cause SWR meters to read differently.
> I've seen this Smith Chart reference before and it makes no sense. You can
> certainly use your feeder to "match" your antenna. Of course, if SWR meters
> didn't care what the impedance is then yes, it wouldn't matter where you put
> it along the line but such is not the case.
> Steve
> N4LQ
>
[hidden email]
>
>
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