----- Original Message -----
From: "Pete Smith" <n4zr@contesting.com>
>> > 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
>
Pete,
Figure 11-6 shows the "current phase shift" of a 50 ohms line
versus electrical length for 3 cases (1 matched, 2 different
mismatches). This is equivalent to ANGLE (Iout | Iin). With
the 90 degree line ANG (Iout | In) <> 90 deg is VSWR <> 1.0,
but ANG (Iout | Vin) = 90 deg for any load impedance. See
paragraph 3.4.5 on W7EL "Current Forcing" properties of 90
degree lines.
73, Mike W4EF........................................
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