We may try another thing. Take a section of the loss less line of a certain length / delay. Split it along into two narrower conductor while keeping the ends at side A and B connected. If by separation or other reason we exclude coupling, here we have a circle with 'circular' impedance twice the original (sqrt(2L/(C/2)) and the same propagation factor and hence the same wavelength: sqrt(2L * (C/2)). For the outer circuit, the only current that is observable is a 'coherent' component, something like a 'common mode'. Nothing forbids the existing of the 'differential' component too, that circulates within the loop. The impedances are different for the 'common' and 'differential' components. But, of course, the differential one does not affect the outer circuitry (as far as we keep traces connected at A and B) and therefore we don't need it. Similarly, the line segment can be split along into arbitrary number of topologically parallel (but uncoupled) filaments not necessary of same thickness, and here we could introduce a many circulating currents for each loop. This is still a valid model but we don't need all this details if the goal is only to find out how the wave propagates from A to B. The concept of loop currents is one of the basics in circuit theory. It represents any branch current as a superposition of the loop currents circulating in the contours that include this branch. However, we do not introduce more than one loop current to keep the system non-singular. With mode than one current for every loop the solution isn't unique >Here's another simple example. Connect two 1V voltage sources, one to=20 >each terminal of a 1 ohm resistor. One can say the potential difference >across the resistor is 0, so by Ohm's law, current is 0. Or one can=20 >ignore one voltage source at a time and say we have 1A going through the=20 >resistor from each source. The currents are in opposite direction=20 >therefore net current is 0. One can label either approach to be=20 >cumbersome or intuitive but I don't think either approach can claim to=20 >solely represent reality. > >Thanks, >Vinu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu