SWR explained in layman's terms. - Kevin needs to see this one.
 

"Jeff Liebermann" wrote in message
...

snip

Somehow, I think we missed a splendid opportunity to add our mark on
technical slang.

How about this story:

A mad scientist invented the Ultimate Brain Machine. At the press of a
button, he could aim a ray at somebody's head and change their IQ.

First, he tested it on a plumber. He pressed "UP," waited a few seconds and
pressed "STOP." The plumber started quoting Shakespeare and explained
relativity in simple terms.

Next , he tested it on an electrical engineering professor, who was also an
Extra Class ham. He pressed the "DOWN" button and waited a few moments.
Just then, the phone rang. It was a call from his nasty, old wife and he
got into a shouting match with her.

When he hung up, he raced over to the machine, now overheated and smoking.
He pressed "STOP and asked the professor if he was all right.

The professor replied, "That's a big 10-4, good buddy!"

Sal

SWR explained in layman's terms. - Kevin needs to see this one.
 

On 3/27/2012 9:29 PM, Jeff Liebermann wrote:

Full disclosu I got my start in radio in about 1965 with an EICO
model something CB radio. Ham radio was available, but I was too lazy
to study for the license. CB was also cheaper and easier. Many years
later, I worked for several companies that manufactured or sold CB
radios in addition to their commercial radio products. I also
designed a CB paging system (that was never produced). When I owned
part of a land mobile radio shop, we also sold and serviced CB radios.
It's really difficult to work in commercial radio, and also avoid CB.
I don't see how you've made it this far, and missed all the CB
history.

While much of the CB lingo is fairly new and amazingly creative, some
of it is based on ham radio lingo, which is not so new or as creative.
Somehow, I think we missed a splendid opportunity to add our mark on
technical slang.

I think I've heard most of it, I just hadn't heard "pill". The short
time I was into the CB craze it was in a pretty rural part of northern
NY, so maybe that term hadn't made it there.

tom

SWR explained in layman's terms. - Kevin needs to see this one.
 

Arky Bob wrote in news:15dd72a9-a378-4362-
:

http://www.youtube.com/watch?v=zOOih...eature=related

I didn't listen to it for long, but long enough to see that it had no
merit.

But, do you think the average ham has a sound understanding?

What about Wikipedia... here is a little extract:

"SWR is used as an efficiency measure for transmission lines, electrical
cables that conduct radio frequency signals, used for purposes such as
connecting radio transmitters and receivers with their antennas, and
distributing cable television signals. A problem with transmission lines
is that impedance mismatches in the cable tend to reflect the radio
waves back toward the source end of the cable, preventing all the power
from reaching the destination end. SWR measures the relative size of
these reflections. An ideal transmission line would have an SWR of 1:1,
with all the power reaching the destination and no reflected power. An
infinite SWR represents complete reflection, with all the power
reflected back down the cable. The SWR of a transmission line can be
measured with an instrument called an SWR meter, and checking the SWR is
a standard part of installing and maintaining transmission lines."

So, from the quote "SWR measures the relative size of those
reflections", and when there is no reflection, the "line would have an
SWR of 1:1". It is internally inconsistent. This is just as flawed as
the videos example of a "radio doin' 10W and only 8W gettin' out, then
you have a signal wave ratio of 1.2".

Now, Widipedia started with a fairly correct statement "standing wave
ratio (SWR) is the ratio of the amplitude of a partial standing wave at
an antinode (maximum) to the amplitude at an adjacent node (minimum), in
an electrical transmission line", just someone had to expand that and
turn it into gobbledegook.

No wonder people get confused.

And Wiki having given a common formula for VSWR(rho) looks like they
considers only a subset of real transmission lines, a rare subset at
that, distortionless lines, when they say "As rho, the magnitude of
Gamma, always falls in the range [0,1], the VSWR is always = +1."
(Gamma is a complex quantity, yet they specify the range in scalar
terms, and it is wrong.)

The difference between hams and chooks is probably one of degree, and
becoming less with passage of time.

Owen