Z0 of a line with unequal wires

[Baluncore]

In my humble but expert opinion;

The asymmetric parallel conductor equation demonstrates that a symmetrical line is better than an asymmetrical line. This is being ignored by modmix because it is inconvenient.

The use of an exposed digital signal would generate all sorts of noise and interference to other systems. This is being ignored by modmix because it is inconvenient.

This topic is no longer about physics. Reality is being ignored by modmix because it is inconvenient.

This topic should be closed.

 

[davenn]

In my humble but expert opinion;

The asymmetric parallel conductor equation demonstrates that a symmetrical line is better than an asymmetrical line. This is being ignored by modmix because it is inconvenient.

The use of an exposed digital signal would generate all sorts of noise and interference to other systems. This is being ignored by modmix because it is inconvenient.

This topic is no longer about physics. Reality is being ignored by modmix because it is inconvenient.

This topic should be closed.

totally agree

 

[modmix]

bye.

 

[sophiecentaur]

And right there is where you are still failing to understand a digital signal
it is a digitally encoded and transmitted signal it is received as such and decoded
there's nothing analog about it
its a string of 1's and 0's, hi's and lo's


Dave

I have to disagree with you there Dave.

The signal that is carried on any channel is analogue. It involves variations of actual voltages or currents in time and is subject to all the impairments that a straight analogue signal would be. It carries digital information. How well that signal survives is a totally analogue problem. The analogue signal may or may not be recognisable, at the other end, as a series of zeros and ones on an oscilloscope. but what is necessary is that the demodulator sees enough of them correctly to reconstitute the original information. This is what error detection and correction is all about. Many poorly implemented decoders fail to deal with the effects of jitter, interference, distortion or noise. That can be due to analogue imperfections or to poor error correcting or masking. Well before the signal actually crashes, there can be perceptible effects on the output programme signal. Before coming to any conclusions about which part of a channel is dodgy, it is necessary to examine the demodulated bit stream for errors and to see if those errors have the sort of statistics that the coding system can cope with (e.g. interleaving is used to reduce the effects of scratches on audio CDs)

I could put it even stronger and say that any transmission or recording channel that actually uses easily recognised ones and zeros (a set of boxcars) is poorly engineered and is wasting channel capacity. Either more data could be squeezed in or the signal level could be reduced.
Digital engineering hangs totally on Analogue techniques.