Albert wrote on Wed, 06 October 2004 17:20 
Perhaps I missed this, but how many bnc tbars can you put in a row before the signal degrades, or is this a concern at all?

As I stated earlier in the thread, the issue of termination is much more impotent for higher frequency digital data (such as AES) than lower frequency (such as WC).
Lets me show an example with some numbers:
Say we have 1000 feet of coaxial cable (very long). That is 800nsec delay. Say we are working with a square wave WC at 96KHz. So a cycle time is about 10uSec. The time between transitions is about 5uSec (assuming a square wave). So how may reflections will occure between 2 transitions?
10usec/800nsec = 12.5 But since we need to account for twice the cable length (reflections travel from source to load and back to source), so we have over 6 round trips.
Now, lets get practical and assume a 5% cable to termination mismatch. So the first reflection yields 2.5% (half the mismatch), the second reflection is 2.5% of 2.5% = .0625%. The third round trip yields 2.5% of .0625%... and at 6 round trips we have 2.4 pico (a millionth of a millionth) of the original step. Say the step was 5V, the reflection activity is truly tiny 1.2nV (nano volt). And that is for 1000 feet of cable.
So the point is, proper termination is almost a joke at WC speed. The same 1000 feet cable with say 1MHz frequency (instead of 96KHz) will be a different story. The same exercise with 1uSec/800nSec = 1.25  a new clock transition
is being sent down the cable before the first reflection had enough time to go through a round trip! So the first reflection which is 2.5%. or .125V "rides on" the 5V signal... That will much things up... That is at 1MHz, imagine faster rate such as AES signal.
Reflections and proper termination are about cable length vs period (frequency). The whole concept of proper termination plays no role at very low frequencies, where audio folks look at a cable as a capacitive medium. 44.1KHz48KHz WC is still very low period about 20uSec. The signal contains high frequencies (fast rise and fall time square wave), but it is the basic period that counts for reflections.
So what is the bottom line? Don't worry about WC reflections. If you want to "be pure", go for short interconnects say 3 feet between units, and the first cable leading to the units can be long. That is all for WC, not for AES. How many units? A pile of units! Assume that each unit input looks like 10KOhm in parallel to say 20pF. Say you have 100 units hooked, thus a distributed load 100 Ohms and that will cost you some in amplitude, but still work fine. The capacitance will muck the purity of the 75Ohm line and so your starting point is no longer 2.5%. Say it is 25%, than the 1000 feet cable example will yield 4mV activity on the next edge. So yes 100 units is potentially on the hairy edge. I would not hesitate to have 25 units.
You could not hear the difference between the system with or without the termination resistor, that is in a double blind test. You would hear it with AES signal.
BR
Dan Lavry