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No Frank I was careless.
When you are determining the area under a curve, the curve has an equation When the graph is roughly drawn out you draw a narrow vertical strip that represents dy/dx That strip has no specific thickness as it represents a vanishingly thin strip. You appear to be confused with the defininition of the integral. You simply integrate the function over the desired range, and should not be concerned with irrelevant concepts, such as strip widths. If the area represented a cross section of a radiator the thickness of that strip is then a problem. No such strip exists in integration. As a radiator dx could represent the skin depth or it could represent the distance from the surface to the center line and thus the cross Not so; "dx" simply refers to the independant variable to be integrated. Note the first example of a "Reimann integral" at: http://mathworld.wolfram.com/Integral.html section would not be homogenous, same density etc The problem then becomes what is the true skin depth density in relation to the inner core which allows for the application of the material resistance. To determine the RF resistance of a conductor requires a solution involving "Kelvin/Thompson" functions; which are modified Bessel functions with a complex argument. See the following for details: http://www.st-andrews.ac.uk/~www_pa/...ect/page1.html Also: http://mathworld.wolfram.com/Bei.html http://mathworld.wolfram.com/Ber.html Now I see skin depth as the point that eddy current becomes a contained current circuit without discontinuity. The books define skin depth as a relation of decay which is not how I see things so we have a difference in proving things one way or the other. Ansoft's (www.ansoft.com) "Maxwell" is a "Finite Element Modeling" (FEM) program which, among other things, can accurately produce a graphical representation of the current distribution in a cylindrical conductor. See examples at: http://www3.telus.net/nighttrainexpr...in%20depth.htm These graphs are reproduced from an article in the November/December issue of QEX magazine, pp20 - 29, by Rudy Severns, N6LF. I then added aunconnected problem by drifting towards integration and limits ie travelling back from integration to the differation format which was a silly mistake for which I have been already reprimanded by the nets monitor who looks out for those things rather than the technical content. Sorry, I don't mean to be insulting, but I am baffled how you can have such problems with elementary math; yet argue about concepts taught in a third year electrical engineering degree program with prerequisites in advanced calculus, partial differential equations, and more. I really believe that the answer lays on Maxwells laws and not with the approximation supplied by Uda/Yagi. I agree, but Yagi and Uda simply build experimental models. Which is about all anybody could do in those days. Computor programs say the same thing via the tipping radiator which all deny so there is no possible solution to be arrived at that satisfies all unless somebody provides answers that reflect Maxwell and not Yagi/Uda rather than "I said so" as every thing is known and is in the books that I own. At no time have I taken your postings as mocking or otherwise insincere as you are the only person who used a antenna program in conjuction with my beliefs which shows radiators as not being parallel with the surface of the Earth where others refused to check in any way. Many hams interested in low frequency DX use sloping (monopole) radiators, which gives a slight improvement in low angle radiation. As I stated in an earlier posting one must graph the current levels at the top of a radiator by superimposing both graphs where both the leading and trailing currents arrive at the end ( time separation of half a period)so that current direction can be determined since in one case there is no eddy current and the other case does have eddy currents( flow resistance) on the surface which thus determines current flow direction at each point. Sorry, but you lost me again. 73, Frank |
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