2007-07-15 08:57:49 · 2 answers · asked by JAMES 4 in Science & Mathematics ➔ Engineering
That depends on several things. Is it vertical, horizontal, at resonance, 1 wavelength above ground, or more, type of feed line, conditions of the feed line, any RF chokes built into the feed line near the antenna feed point. Is there a ground plane close by, if so, what is it? Typically, in actual practice, the "Z" or impedance is going to be 30 to 50 ohms.
A good reference book for this would be the ARRL Handbook. While there are more exhaustive books available from other sources, and the ARRL itself, the Handbook is a good general reference for theory as well as practical application.
2007-07-15 15:18:50 · answer #1 · answered by Anonymous · 0⤊ 0⤋
an antenna element that is half lamba will be resonate at the operating frequency. the impedence will depend on the location and type of coupling to the feedline. If center fed it will nominally show a free space impedence of 72 ohms resistive with no reactance.
2007-07-15 09:33:43 · answer #2 · answered by lare 7 · 0⤊ 0⤋