Talk:Standing wave ratio

message: Note to ssd: I added a mention that the reflection coefficient is complex. Perhaps there is more we could say about this quantity, but I suggest that extra information goes in to the reflection coefficient article, not this one.  Unless, that is, you care to explain how the phase of ρ can affect the SWR.  That is beyond my understanding, but you might like to have a go. -- Heron 12:14, 24 Jul 2004 (UTC)
replies: text: Probably mentioning phase angle is enough, although one of these articles (perhaps not this one) should mention complex conjugate impedance match.  Actually,now that I think about it, that would best go in an article on antenna tuner which does not yet exist.  As you said before, probably the equations for resistive loss and dielectric loss should go in the transmission line article where it talks about decibels per foot. --ssd 17:01, 24 Jul 2004 (UTC)
thread_title:  Reflection coefficient is complex 

message: It seems being a paradox.
For
:\mathcal {\mid}\Psi(x,t){\mid}^2=A^2sin^{2}(kx)*cos^{2}({\omega}t)=0 {\neq}1 
which means that it does not equal to 1. Thus caused not coresponse Normalization. Known a standing wave is expressed as
:\mathcal, \Psi(x,t)=Asin(kx)*cos({\omega}t), .
Can anyone talk about your thoughts? Thanks.
*One more question that what's difference between phase velocity and group velocity? My opinions and thoughts:
::By their math expression we can clearly find angular frequency of \mathcal V_p , \mathcal \omega  which keeps constant when a wave vibrates up and down localized. That may because of energy transports into a wave is conservative,just like a particel moves up and down in a Y axis,localizedly(which keeps energy conservative).
::But for another one,it travels in an X axis,that hints its phase-angular is the function of time. By time changes,then \mathcal \omega  naturely changes either.
I'm a little not sure above. Could anyone discuss with me?
--HydrogenSu 11:47, 7 February 2006 (UTC)
thread_title:  Standing Wave Math Expression 

message: The third paragraph of the lede makes it sound as though the VSWR is a property of the transmission line; the vast majority of the reflection will occur at the junction with the load or from within the load (barring backhoe fade). --catslash (talk) 02:03, 14 March 2012 (UTC)
replies: text: Not sure if this is the intended point of the author, but it is indeed true that VSWR is used as a quality measure by cable manufacturers.  I found some references on this while writing Nominal impedance#Cable quality.  Of course, I agree with your statement also; cable testing requires precision adjustment of the termination first to be meaningful. SpinningSpark 08:32, 14 March 2012 (UTC)
thread_title: Lede

message: There is something wrong with the further analysis.  According to the result min voltage always occurs at x=0.  Clearly, this is only true for resistive loads less than Z0.  The mistake seems to be ignoring the phase of Γ, but I haven't worked through it in detail. Also the diagram contradicts this by showing max voltage at x=0.  Might be an idea to state where x is being measured from. SpinningSpark 13:28, 19 November 2013 (UTC)
thread_title:  Further analysis section 

message: I don't see the advantage of changing the symbol used for the magnitude of the reflection coefficient from \rho to |\Gamma|.  The former makes for cleaner expressions in my opinion, but in any case, I don't think that it is acceptable to half change the article as it now stands.  It should be all or nothing, including the diagram. SpinningSpark 16:22, 27 November 2014 (UTC)
replies: text: Well go back to the old version and look carefully. Rho was used for the magnitude of Gamma. It was just used in a couple locations and it didn't seem to require its own symbol for any good reason since writing |Gamma| doesn't take up much more space. I could see substituting repeated uses of a complex expression with an easier symbol, but in this case it would more likely introduce confusion (if they didn't read the definition of rho carefully) than clarity.Interferometrist (talk) 17:20, 27 November 2014 (UTC)

text: But you're right about the diagram though. I guess if you really want that diagram, then you should change back to rho. I didn't think the diagram was too useful to a general reader and would prefer to look for a different one. A good one, in my opinion, would be one that showed the standing wave pattern with a composite showing the net voltage at different time phases, and the SWR showing up as the envelope (of course you can only do that for one SWR in one picture). The original presentation in that section did have x as a measure of distance, but didn't show where the end of the line and load was located (so I made it explicit), so the correspondence between the figure and the text wasn't so clear. I guess, according to the figure, the line ends at 3pi, with Gamma being real positive. But how often is a line exactly 3/2 wavelengths long? (Or did it really start at x=0?). Interferometrist (talk) 17:35, 27 November 2014 (UTC)

text: And actually it's worse than that (possibly the reason for the section being tagged). According to the first equations, it would appear that the load was at x=0 and gamma is positive real. And with the forward wave in the +x direction (thus x is always negative along the line). So that didn't correspond to the figure at all. Of course you could reintroduce the figure stating x_0 = 3pi and spelling out rho. But as I said, the figure isn't so helpful in my opinion, and certainly shouldn't be inconsistent with the equations.Interferometrist (talk) 17:44, 27 November 2014 (UTC)
replies: text: I don't agree with your argument that the user will get confused if they don't read the definitions.  Of course they will, but they could get just as confused with |\Gamma| if they don't read the definition of \Gamma. SpinningSpark 19:13, 27 November 2014 (UTC)
thread_title:  Symbol for reflection coefficient 

message: , I find it baffling why you have demoted the article to start class.  The requirement for C class (in part) is "The article is substantial, but is still missing important content...".  The page has nearly 4000 words of readable prose.  It is difficult to see how that cannot be substantial.  The reader experience for C class is "Useful to a casual reader, but would not provide a complete picture for even a moderately detailed study."  Reader experience for Start class is "Provides some meaningful content, but most readers will need more."  Demoting the article implies that either the article is not useful to a casual reader, or that most readers will require more information.  So can you explain how the article fails one of those criteria? SpinningSpark 15:26, 21 March 2017 (UTC)
replies: text: you have presented some really valid arguments. I agree with you on this. I am changing this back to Class C. Thanks for pointing this out. Steve Quinn (talk) 04:32, 24 March 2017 (UTC)
thread_title:  Article rating