Re: 75ohm Impedance question K3S and Antenna side.
Posted by
John K9UWA-2 on
Apr 01, 2020; 3:52am
URL: http://elecraft.85.s1.nabble.com/75ohm-Impedance-question-K3S-and-Antenna-side-tp7659364p7659403.html
Cut the hardline to multiples of 1/2 wavelength and the swr will be 1 to 1 on both
ends. 50 in 50 out. In this case the OP needs around 200 feet. Once your get the
velocity factor for the 1/2" hardline... that is ballpark 80 to 83%. for 3.540 mhz is
265 feet x .8 = 212 feet. If you don't have a piece of test gear to get it cut
correctly then put a 50 ohm dummy load at the far end keep cutting until your
wattmeter says 1 to 1 swr. 1/2 wave multiples will hit most of the ham bands. A
little high in the 30m band. Close enough.
73
John k9uwa
John Goller, K9UWA & Jean Goller, N9PXF
Antique Radio Restorations
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Visit our Web Site at:
http://www.JohnJeanAntiqueRadio.com4836 Ranch Road
Leo, IN 46765
USA
1-260-637-6426
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