![]() |
W4JLE wrote:
One can NOT see a standing wave, whereas one may be computed from the observations. Standing waves are in fact the observable result of the superposition of traveling waves. Interferometers are devices which function because of the fact that standing wave interference patterns are observable. Radio interferometers allow us to do radio astronomy with improved spacial resolution. We most certainly can see standing waves. 73, Jim AC6XG |
|
Cecil Moore wrote in message ...
Richard Harrison wrote: Cecil is getting at the effective value of an a-c waveform which is rms. Slick and Cecil are talking about two different things. I was a little sleepy when I wrote that. It didn't occur to me until later that Slick can also use dQ/dt = 0 over a complete cycle to prove that the average value of any AC current is zero, not just at a voltage node. Hence the necessity for RMS values for AC. That's not what i meant. I mean that with full reflections, there will be nodes space 1/2 wavelengths apart that will have 0 RMS AC current. These points will coincide with the absolute peak voltages that occur on the line. If Slick can tell a forward wave from a traveling wave by taking one and only one current measurement at one point on a transmission line, and knowing nothing else about the system, he is a better man than I. More of your TRULY confusing terminology! It really helps you cloud the argument, doesn't it! Unfortunately, if you don't understand someone, it usually means they are full of sh**! A forward wave is a traveling wave, traveling forward. If you give me the Max RMS AC current, and the Min RMS current, i can most certainly tell you what the SWR is. S. |
"Jim Kelley" wrote in message ... W4JLE wrote: One can NOT see a standing wave, whereas one may be computed from the observations. Standing waves are in fact the observable result of the superposition of traveling waves. Interferometers are devices which function because of the fact that standing wave interference patterns are observable. Radio interferometers allow us to do radio astronomy with improved spacial resolution. We most certainly can see standing waves. 73, Jim AC6XG being able to 'see' them is how they got their name. you could run a neon bulb or other voltage or current detector along an open wire line and 'see' the standing wave voltage and current peaks and nulls... that was of course in the days before they would have warned you to stay far, far away from sources of rf exposure like that. |
Dr. Slick wrote:
A forward wave is a traveling wave, traveling forward. If you give me the Max RMS AC current, and the Min RMS current, i can most certainly tell you what the SWR is. That's two measurements which violates the challenge. Given one and only one current reading, is the current traveling or standing? The fact that you cannot tell the difference means the two currents possess the same nature, i.e. magnitude, phase, and direction. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Jim Kelley wrote:
So much for people who don't understand the difference between current flow, and wave propagation. :-) I've been talking about electron current flow, Jim, I don't recall making any assertions about wave propagation. Waves and currents are associated but are quite different things. Since the waves travel at the speed of light, I assume photons are involved. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
Cecil wrote,
Jim Kelley wrote: Cecil Moore wrote: Here's what the standing wave current looks like when it is not frozen in time. That's the topic of discussion that everyone seems to want to avoid. Standing waves don't stand still. They probably should have been called "looping waves". http://einstein.byu.edu/~masong/HTMs...newave2EX.html I guess that kind of thing can be exciting for the unitiated. Good for you, Cecil! So much for some people I know who assert, "Standing waves don't move." :-) -- 73, Cecil http://www.qsl.net/w5dxp They change but they don't move. 73, Tom Donaly |
Cecil Moore wrote: Waves and currents are associated but are quite different things. That's what I've been saying. Make sure you remember and apply that concept when you're talking about 'direction'. 73, Jim AC6XG |
Tdonaly wrote:
They change but they don't move. Maybe it's relativity in action. The current stands still and the earth moves around it? -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
|
All times are GMT +1. The time now is 01:51 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com