Re: Amazing video from ATT archives freely available on youtube

Laurence Oberman

Yep, For me the thing about this video was the ingenuity to use the
pivoting metal rods like that to show the wave motion.
Amazing, still cant get over how he came to that idea.

On Thu, Apr 25, 2019 at 4:45 PM Jerry Gaffke via Groups.Io
<> wrote:

SWR was about the only thing they could measure 100 years ago,
just run some sort of RF voltmeter along the open wire transmission line to the antenna
and measure the peaks and troughs.

Would be more informative to know the complex impedance of the load,
but SWR is still easier to measure and it's what hams are most familiar with.

Jerry, KE7ER

On Thu, Apr 25, 2019 at 08:01 AM, Tom, wb6b wrote:

Additional comment: The mechanical depiction of SWR video was really interesting, too. Just one point. If you don't have a significant part of a wavelength in a cable or other connection, SWR really is not a factor. Unless you are dealing with microwaves, if you are talking about the impedance match between stages in a transmitter, most likely a "mismatch" in driving the finals (for example, as I often hear described) is not reflecting anything nor has an SWR. But it is still a convenient way to describe impedance matching as so many tools, like smith charts, are built around the concept.

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