On Wed, 16 Jan 2008 21:48:33 -0800, "CalifBill"
wrote:


"John H." wrote in message
.. .
On Wed, 16 Jan 2008 06:52:36 -0500, "Jim" wrote:


wrote in message
...
On Tue, 15 Jan 2008 17:07:42 -0800 (PST), wrote:

On Jan 15, 7:50 pm, Tim wrote:
OK, I picked this up on another board,a nd seeing that Eisboch, Tom,
Gene and Larry have had dealings with this stuff. I thought I'd
present it here. It has my curiosity up as well.

I'm not up on physics, concerning this so here goes:

"I searched the web but couldn't find an answer to a simple question
which for my purposes is really a matter of curiosity. Of course,
sometimes these
kinds of questions end up teaching me the most.

Most defintions of wavelength are along the lines of the distance
between points of corresponding phase of two consecutive cycles of a
wave. I'm not
an idiot , so I understand what is a pretty
straightforward definition.

What I don't get is why the term length? I mean, they don't call the
amplitude the waveheight. I kind of think of it as a wavegap. If you
painted a big sine wave on the street and asked me how long it was,
I'd get one
of those little rolling doohickies for measuring and trace the line
through its curve. Without knowing the definition in advance, I
wouldn't think you would
be asking me the straight distance between two points of
corresponding
phase.

I ask this question because I don't understand why it's called what
it's called, not because I want to tell the experts they got it
wrong. It's bugged me for a while, so I've finally decided to take the
plunge and risk looking stupid.

Thanks in advance for any responses or links to read..."

--
Jim Carr

It is called "length" because it truly is a length.

Wavelength is usually stated as "Peak to Peak", or pp


which is 180 degrees, right? ;-

For a sine wave, 2 pies (apple?), or 360 degrees.
--
John H

what if it is not a sine wave?


Then the period may be different. The function y=sinx has a period of 360
degrees. The function y=sin2x has a period of 180 degrees. The function
y=x/2 has a period of 720 degrees.

If the function is changed to y=2sinx, then the period is 360 degrees, but
the amplitude is 2, instead of 1.
--
John H

Eisboch wrote:
wrote in message
...
It can be measured using an oscilloscope.



You can measure the amplitude and frequency. You'd have to calculate the
wavelength.

Eisboch


Never used a slotted waveguide, eh?

"Del Cecchi" wrote in message
...
Eisboch wrote:
wrote in message
...
It can be measured using an oscilloscope.



You can measure the amplitude and frequency. You'd have to calculate the
wavelength.

Eisboch
Never used a slotted waveguide, eh?


For microwave or radar, yes. For HF or VHF RF , no.
I *have* used Gene's Time Domain Reflectometer though, for finding faults in
long transmission coaxial lines.

Eisboch

"Short Wave Sportfishing" wrote in message
...
On Wed, 16 Jan 2008 21:44:04 -0800, "CalifBill"
wrote:


"Jim" wrote in message
. ..

"Eisboch" wrote in message
...

"Jim" wrote in message
...


The definition of peak to peak must have changed since I was in A
school. I was taught that positive peak to negative peak or negative
peak to positive peak shal be called peak to peak. (Neener Neener)

Sure. I don't disagree. Usually the term "peak to peak" relates to
amplitude measurements. But, a positive peak to the next negative peak
is 180 degrees if you are looking for frequency over a time period. A
positive peak to the next positive peak is 360 degrees. Or negative to
the next negative. Or any other point to the next repeating point on
the
waveform.

Eisboch

360 degrees= 1 cycle is the description I was looking for. Quit trying
to
confuse me with facts.
Check tonights Tampa news videos.

Actually may not be 360 degrees. What if it is a square wave?

The same way.

I know the measurement is the same, but if a square or triangular wave,
would it be 360 degrees?

wrote in message
news
On Thu, 17 Jan 2008 06:28:39 -0500, "Jim"
wrote:


"CalifBill" wrote in message
...

"Jim" wrote in message
...

"Eisboch" wrote in message
...

"Jim" wrote in message
...


The definition of peak to peak must have changed since I was in A
school. I was taught that positive peak to negative peak or negative
peak to positive peak shal be called peak to peak. (Neener Neener)

Sure. I don't disagree. Usually the term "peak to peak" relates to
amplitude measurements. But, a positive peak to the next negative
peak
is 180 degrees if you are looking for frequency over a time period.
A
positive peak to the next positive peak is 360 degrees. Or negative
to
the next negative. Or any other point to the next repeating point on
the waveform.

Eisboch

360 degrees= 1 cycle is the description I was looking for. Quit trying
to
confuse me with facts.
Check tonights Tampa news videos.

Actually may not be 360 degrees. What if it is a square wave?

In that case you would probably be talking PRR. This discussion is
starting
to get over my head so I'll bow out and let you engineers have at it.

Giving you a sinuous headache? :-)



LOL.

wrote in message
...
On Wed, 16 Jan 2008 21:41:45 -0800, "CalifBill"
wrote:


wrote in message
. ..
On Wed, 16 Jan 2008 13:23:20 -0800, "Calif Bill"

wrote:


Actually is 180 degrees for a peak to peak on a sign wave. But for
frequency, it is point to same point on the next wave. You could
measure
it
anywhere on the wave. But Positive peak to Positive peak or Negative
peak
to Negative Peak or + or - zero crossing all work.

Frequency = 1/ time.

Wave length = speed of wave / frequency. This will work for sound at
about
1126 ft/ second or 300 m/s for radio.


What's the matter Bill? Didn't the website you Googled know how to spell
sine?

Bwhahahahahahaha!



Me bad. Especially for misspelling sine. I know all that stuff. My
degree
is in Electronic engineering. As well as the fact I worked on repairing
Radar and Instrument landing systems and nav aids in the Air force. As
well as part of my patent includes Sine Square + Cosine Square = 1.

If I had googled it, I would have spelt Sine correctly.


Harry... Dat you?

Nope, I actually did work on the stuff. I have part of a patent on flaw
scanning disk drives where part of the circuitry depends on Sine Square +
Cosine Square = 1. Interesting part of a flaw in the media, is if it is
under the head, you will get reduced amplitude, but if off to the side, you
will get a phase shift. Was always hard to detect the flaws off to the
side. So if you compare the signal coming off the disk if it is written so
it will be a sine wave, and compare the signal + and - 45 degrees and run it
through a adder circuit and the output will be 1 until a phase shift and the
output signal will decrease and you can detect defects off the center line
of the tract.

wrote in message
news
On Thu, 17 Jan 2008 06:28:39 -0500, "Jim"
wrote:


"CalifBill" wrote in message
...

"Jim" wrote in message
...

"Eisboch" wrote in message
...

"Jim" wrote in message
...


The definition of peak to peak must have changed since I was in A
school. I was taught that positive peak to negative peak or negative
peak to positive peak shal be called peak to peak. (Neener Neener)

Sure. I don't disagree. Usually the term "peak to peak" relates to
amplitude measurements. But, a positive peak to the next negative
peak
is 180 degrees if you are looking for frequency over a time period.
A
positive peak to the next positive peak is 360 degrees. Or negative
to
the next negative. Or any other point to the next repeating point on
the waveform.

Eisboch

360 degrees= 1 cycle is the description I was looking for. Quit trying
to
confuse me with facts.
Check tonights Tampa news videos.

Actually may not be 360 degrees. What if it is a square wave?

In that case you would probably be talking PRR. This discussion is
starting
to get over my head so I'll bow out and let you engineers have at it.

Giving you a sinuous headache? :-)

No. But i am experiencing sinusoidal disenchantment

wrote in message
news
On Thu, 17 Jan 2008 06:28:39 -0500, "Jim"
wrote:


"CalifBill" wrote in message
...

"Jim" wrote in message
...

"Eisboch" wrote in message
...

"Jim" wrote in message
...


The definition of peak to peak must have changed since I was in A
school. I was taught that positive peak to negative peak or negative
peak to positive peak shal be called peak to peak. (Neener Neener)

Sure. I don't disagree. Usually the term "peak to peak" relates to
amplitude measurements. But, a positive peak to the next negative
peak
is 180 degrees if you are looking for frequency over a time period.
A
positive peak to the next positive peak is 360 degrees. Or negative
to
the next negative. Or any other point to the next repeating point on
the waveform.

Eisboch

360 degrees= 1 cycle is the description I was looking for. Quit trying
to
confuse me with facts.
Check tonights Tampa news videos.

Actually may not be 360 degrees. What if it is a square wave?

In that case you would probably be talking PRR. This discussion is
starting
to get over my head so I'll bow out and let you engineers have at it.

Giving you a sinuous headache? :-)

No. But I am experiencing sinusoidal disenchantment.

wrote in message
...
On Thu, 17 Jan 2008 07:24:22 -0800, "Calif Bill"
wrote:


wrote in message
. ..
On Wed, 16 Jan 2008 21:41:45 -0800, "CalifBill"

wrote:


wrote in message
m...
On Wed, 16 Jan 2008 13:23:20 -0800, "Calif Bill"

wrote:


Actually is 180 degrees for a peak to peak on a sign wave. But for
frequency, it is point to same point on the next wave. You could
measure
it
anywhere on the wave. But Positive peak to Positive peak or Negative
peak
to Negative Peak or + or - zero crossing all work.

Frequency = 1/ time.

Wave length = speed of wave / frequency. This will work for sound at
about
1126 ft/ second or 300 m/s for radio.


What's the matter Bill? Didn't the website you Googled know how to
spell
sine?

Bwhahahahahahaha!



Me bad. Especially for misspelling sine. I know all that stuff. My
degree
is in Electronic engineering. As well as the fact I worked on repairing
Radar and Instrument landing systems and nav aids in the Air force. As
well as part of my patent includes Sine Square + Cosine Square = 1.

If I had googled it, I would have spelt Sine correctly.


Harry... Dat you?

Nope, I actually did work on the stuff. I have part of a patent on flaw
scanning disk drives where part of the circuitry depends on Sine Square +
Cosine Square = 1. Interesting part of a flaw in the media, is if it is
under the head, you will get reduced amplitude, but if off to the side,
you
will get a phase shift. Was always hard to detect the flaws off to the
side. So if you compare the signal coming off the disk if it is written
so
it will be a sine wave, and compare the signal + and - 45 degrees and run
it
through a adder circuit and the output will be 1 until a phase shift and
the
output signal will decrease and you can detect defects off the center line
of the tract.


I was just teasing you, Bill.



And it is pretty kool that one can expound on a patent concerning disk
drives on a boating newsgroup. ;-

"Calif Bill" wrote in message
...

wrote in message
...
On Thu, 17 Jan 2008 07:24:22 -0800, "Calif Bill"
wrote:


wrote in message
...
On Wed, 16 Jan 2008 21:41:45 -0800, "CalifBill"

wrote:


wrote in message
om...
On Wed, 16 Jan 2008 13:23:20 -0800, "Calif Bill"

wrote:


Actually is 180 degrees for a peak to peak on a sign wave. But for
frequency, it is point to same point on the next wave. You could
measure
it
anywhere on the wave. But Positive peak to Positive peak or Negative
peak
to Negative Peak or + or - zero crossing all work.

Frequency = 1/ time.

Wave length = speed of wave / frequency. This will work for sound
at
about
1126 ft/ second or 300 m/s for radio.


What's the matter Bill? Didn't the website you Googled know how to
spell
sine?

Bwhahahahahahaha!



Me bad. Especially for misspelling sine. I know all that stuff. My
degree
is in Electronic engineering. As well as the fact I worked on
repairing
Radar and Instrument landing systems and nav aids in the Air force.
As
well as part of my patent includes Sine Square + Cosine Square = 1.

If I had googled it, I would have spelt Sine correctly.


Harry... Dat you?

Nope, I actually did work on the stuff. I have part of a patent on flaw
scanning disk drives where part of the circuitry depends on Sine Square +
Cosine Square = 1. Interesting part of a flaw in the media, is if it is
under the head, you will get reduced amplitude, but if off to the side,
you
will get a phase shift. Was always hard to detect the flaws off to the
side. So if you compare the signal coming off the disk if it is written
so
it will be a sine wave, and compare the signal + and - 45 degrees and run
it
through a adder circuit and the output will be 1 until a phase shift and
the
output signal will decrease and you can detect defects off the center
line
of the tract.


I was just teasing you, Bill.



And it is pretty kool that one can expound on a patent concerning disk
drives on a boating newsgroup. ;-

This is a boating newsgroup?