This mail was sent from ELTA SYS LTD. Feb-25th-03 Hello, I've been reading Mr. Eric Bogatin's "Lossy Transmission Lines: Plain and Simple" paper and have a question, which I hope those of you who have also read it could answer (The same reasoning I present here also follows, to my understanding, from Mr. Howard Johnson's "Black Magic" book, App. B): On page 21 of his paper, Mr. Bogatin presents the Root-of-Sum-of-Squares equation for calculating the rise-time at the end of a lossy transmission line, as a function of the driver rise-time and the 3-dB rise-time of the interconnect. It seems from this paper as if one can cascade several interconnects and get the total effective rise-time of the whole interconnect by using the equation as follows: Take the individual 3dB-rise-times of the individual interconnects and take the square-root of their sum of squares. But it seems there is a problem with this use of the equation. One can take a long interconnect, and calculate its effective rise-time using 2 methods: as an un-divided interconnect, or sub-divide it to (e.g.) 2 identical halves, and do the arithmetic again. Using the 2nd method one gets a result which is (1/square-root of 2) of the "undivided" calculation rise-time. This is a strange result, so I must be missing something, but what? Thanks for anyone who can help Itzhak Hirshtal Elta Systems Israel This message is processed by the PrivaWall Email Security Server. ------------------------------------------------------------------ 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 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