July 8th 15, 07:14 PM
posted to rec.radio.amateur.antenna
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First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
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An antenna question--43 ft vertical
John S wrote:
On 7/7/2015 1:44 PM, wrote:
Ian Jackson wrote:
In message , Jerry Stuckle
writes
Sure, there is ALWAYS VSWR. It may be 1:1, but it's always there.
If there's no reflection, there can be no standing wave. So, being
pedantic, there's no such thing as an SWR of 1:1!
Despite the name, VSWR is defined in terms of complex impedances
and wavelengths, not "waves" of any kind.
Actually, VSWR is defined as the ratio of Vmax/Vmin.
Actually, VSWR can be defined several ways, one of which is:
(1 + |r|)/(1 - |r|)
Where r is the reflection coefficient which can be defined a:
(Zl - Zo)/(Zl + Zo)
Where Zl is the complex load impedance and Zo is the complex source
impedance.
Note that a complex impedance has a frequency dependant part.
--
Jim Pennino
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