On Fri, Mar 4, 2011 at 5:25 AM, Brian Gregory wrote: > In-Reply-To: > > Manu, > >> On Fri, Mar 4, 2011 at 3:50 AM, Michael Watterson wr= ote: >> > On 03/03/2011 21:11, Manu Abraham wrote: >> >> Other than that, there would be Line Amplifiers/Drivers driving those >> >> cables Those cables do look cheap/thin (probably), unlike the rather >> >> thick low capacitance/loss cables. In some cases, coiling cables can >> >> act as an attenuator in cases of overdrive at the consumer equipment >> >> side Simple thing, but works well. >> > coiling doesn't affect the actual signal at all. Only common mode. >> >> It sure does. http://www.ham-radio.com/k6sti/balun.htm >> > > Those coils only become baluns because unwanted common mode currents are > illiminated. Nothing else is happening. Ah, yes. true. They are not simply there to avoid dangling and vandalism. Generally, a few turns of copper on the PCB of a RF receiver for an TL impedance match is used, which came to mind suddenly, when I read dangling and vandalism (equivalent circuit: R-L series, C across the said R-L, parasitic capacitance Cp of PCB from that output to GND). Other than that, in many cases high speed digital communication devices also see the track as a TL. As I wrote earlier, after writing that post only did I think that attenuation would be in the common mode as both conductors are involved, thereby achieving a higher CMRR. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .