RadioBanter - View Single Post - An antenna question--43 ft vertical

[email protected] · July 9th 15, 06:35 AM posted to rec.radio.amateur.antenna

John S wrote:
On 7/8/2015 4:51 PM, wrote:
John S wrote:
On 7/8/2015 1:14 PM, wrote:
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.

So, since Vmax/Vmin (the base definition) has no frequency dependent
part, does that invalidate it?

The "base definition" can be whatever set of equations you pick that
are true.

BTW, the Vmax/Vmin DOES have a frequency dependant component that
determines WHERE Vmax and Vmin occur.

You are just being argumentative. The WHERE doesn't matter in measuring
VSWR. You still measure correct VSWR wherever the locations.

Can you measure VSWR on a 1 meter long Lecher line at 1 MHz?

--
Jim Pennino