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Old January 25th 14, 03:08 PM posted to rec.radio.amateur.antenna
Jerry Stuckle Jerry Stuckle is offline
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First recorded activity by RadioBanter: Oct 2012
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Default Relationship Between Antenna Efficiency and Received Signal Strength

On 1/25/2014 6:18 AM, Jeff wrote:

Whilst I agree with your first point, Smiths Charts do not "explain what
is happening inside of a piece of coax X inches long". They are an easy
way to plot impedances, and show what happens if you *change* the length
of coax, but more importantly they give you an easy way of working out
how to match impedances (with or without any length of coax involved).
They can also display other valuable quantities such as Q.

jeff


They do if you know how to use them properly. For instance, they will
tell you when the reactive portion of the impedance is zero (neither
capacitive nor inductive), which indicates resonance. They will also
tell you the antenna's impedance at a specific frequency. Both can be
used to indirectly determine antenna efficiency.


Rubbish, they tell you nothing more than the impedance at the point
that you wish to plot it. They tell you nothing about how well an
antenna may, or may, not radiate. A 50 ohm resistor will be purely
resistive (parasitic elements neglected) but won't radiate well. Also an
antenna does not have to resonant to radiate well or have high efficiency.

Jeff


Keep thinking that, Jeff, while those who know how to use Smith Charts
continue to design antennas.

Your ignorance is underwhelming.

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