Re: K3 SWR Accuracy - reprise
Posted by
P.B. Christensen on
Nov 04, 2009; 11:30pm
URL: http://elecraft.85.s1.nabble.com/K3-SWR-Accuracy-reprise-tp3943810p3949077.html
> That assumes there is no RF on the exterior of the coax and the SWR
> sensors are ideal. Neither is the case and from personal experience I
> can tell you that the swr meters will change readings based on coax
> length.
The SWR *reading* may change as a function of coax length when current is
present on the outer conductor, but as Phil states, the actual line SWR does
not change, neglecting any line loss. In a mismatched condition, the Z
measured at the line input does change with line length and as F increases,
it takes smaller changes in line length to see changes in input Z.
To deal with the problem Eric describes, I use choking line isolators
between the transceivers and amps, immediately after the amp, and depending
on the antenna type, again at the antenna feed point for most antennas with
a coaxial feed point.
Paul, W9AC
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.html