Hello gurus, I have just encountered some fuzzy questions . On the twisted-pair link there is a Stub , the topo looks like this transformer1 ----------------rj45------transformer2 \ \ (stub) \ \ Test_point all trace were coupled line but were not exact 100ohms diff impedence , the stub length was about 12mm. we know the stub will causing reflection, ringing etc. The result was that the Transformer2's location influenced the error rate, sometime more or less . I cant got the exact reason of it and just only came down to the stub's effect, Does anyone would give more detailed explanations about it . Not changing this Topo, is there any methods to solve this problems ,such as termination , or else thanks -- Best regards, qzheng ================================================== ZhengQi, Wuhan Research Inst. of Posts & Telecommunications #88, Youkeyuan Rd, Wuhan, Hubei, 430074, China Web site http://www.fiberhome.com.cn Phone: +86-27-87691643 mailto:qzheng@xxxxxxxxxxxxxxxx ------------------------------------------------------------------ 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