> I'm amazed so many people buy tuners instead of building them, or
> using stubs.
> 73, Tom W8JI
One of the simplest, practical, and cost-effective solutions to those who
use open feeder/ladder line with multi-band antennas is the approach
re-introduced by Cecil, W6RCA. Cecil has been an advocate of changing
transmission line length in order to achieve a reasonably close 50-ohm
transmitter match into the transmission line. I believe the concept of
changing the length of one's transmission line to vary the antenna system's
input impedance can be traced back to the early '30s when link-coupling was
popular. Since the matching range of the link network was oftentimes
limited, varying the length of the line was a solution to bring the system's
impedance within the range of the link.
By Goodman's "My Transmission Line Really Does Tune my Antenna" does a great
job of explaining the differences on the effect of line impedance as a
function of transmission line length. I believe the article was first
published in a 1950s QST and has been re-printed periodically since then. I
wish they would print it every year.
Anyway, Cecil's method of varying line length with relays is simple and
effective. You can read more about it here...
http://people.delphi.com/cecilmoore/mystery.htm
-Paul, W9AC
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