UNIBUS extension card/cable sets

[Paul Koning]

> On Jun 26, 2015, at 3:58 PM, John Wallace <johnwallace4 at yahoo.co.uk> wrote:
> 
> [huge snippage for brevity, apologies for rubbish formatting]
> 
> I'm not 100% sure I'm right in what follows (it's been a long time) but improvements are welcome. It builds on much of what has already been said.
> 
> Termination has been covered by various contributors - termination reduces (but may not completely eliminate) reflections.

More precisely: terminating a transmission line in its characteristic impedance eliminates the reflection.  Terminating it with something that differs from the characteristic impedance will produce a reflection whose magnitude and phase depends on the mismatch.  Open and short are extreme examples of mismatches, but any mismatch will produce a reflection.  

	paul