Peak phase error due to transmission line mismatch occurs with
lines that are an odd number of 1/8th wavelengths long. The
are no phasing errors due to mismatch when the lines are any
multiple of 1/4 wavelength.
In an array of phased Yagis, phasing errors due to mismatch
are completely eliminated if all of the phasing lines are directly
connected together at the common point. This allows the
phasing lines used in phased Yagis to be any length
In phased Yagi arrays, there may be some advantage to using
line lengths that are odd multiples of a 1/4 wavelength -- if, and
ONLY if -- there is no matching network at the feedpoint (direct
50 ohm feed with no hairpins, beta matches, gamma matches, t-
matches, etc).
In phased verticals, errors due to phasing line mismatch can be
a serious source of phasing errors if the phasing lines are any
length other than a multiple of 1/4 wavalength. This is because,
in phased verticals (other than broadside arrays), the phasing
lines are typically not directly connected together at the
common point. There is usually a phasing network at the
common point
73
Frank
W3LPL
donovanf@erols.com
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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