[TowerTalk] 135deg cable

Pete Smith n4zr at contesting.com
Tue Apr 17 13:48:37 EDT 2007


At 09:06 AM 4/17/2007, Roger D Johnson wrote:
>donovanf at starpower.net wrote:
> >
> > The phase delay of any transmission lines is  N O T  the same as its
> > electrical length except when either of these two special conditions is 
> met:
> >
> >
> >
> >    2. if the line length is any multiple of exactly 90 degrees, its 
> phase delay is the same as its electrical length and the phase delay
> > is not dependent on the VSWR on the line.
> >
> >
>I don't think this is true. My old memory says the length is 180 deg.
>
>73, Roger


You're right.  On page 11-7 of the current edition of the ON4UN book, Fig. 
11-6 charts phase shift vs line length for various load mismatches.  For a 
given mismatch the phase error appears greatest at 90 degrees and zero only 
at 0 and 180 degrees.

73, Pete N4ZR





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