QUOTE (Gordon H @ 15 Feb 2008, 22:15)
<{POST_SNAPBACK}>But it does matter.
Apparently solving a problem without knowing how or why the cure works does not really constitute a solution, certainly not a repeatable one. Without understanding its mechanism, you cannot know for sure that the problem won't re-occur when presented with a slightly different, but equally valid set of conditions.
A DSO is precisely the sort of thing that SHOULD be taken along when investigating this kind of matter, so that the effects can be understood and quantified for future reference and explanation. Otherwise, we go round the whole thing time and again when others inevitably ask the same question.
*** Gordon, you may enjoy the technical discussions / have a far deeper set of knowledge than most on this sort of subject and I will give you a qualified answer.
"Yes of course it matters that in the background, each recommendation is based on fact - but it is NOT helpful to over-technify issues on a general list where modellers want simple best practice guidelines and fixes".
It is of course possible to quantify anything in isolation - however every layout is a non-repeatable set of "wire knitting", with more or less of the small errors or issues that create problems - so any qualification has little or no merit.
If I was to take an analytical approach to WHICH of the problems was mostly guilty on a layout before I touched it then I'd waste hours when I could already have most of them fixed. Each contributes more or less depending on the layout, each is a real issue - that is all that matters.
To see the scope of such things / if you wish for an example please look at the latest NMRA "Clear Block" article by Didrik Voss, the technical chair of the NMRA - he simulated DCC bus configurations and prolems and analysed them VERY well. ie - he created a simulated typical modellers bus configuration, then measured the results - following this with various approaches and filters to fix it. His analysis was professional and really well presented. You'll need to be an NMRA member to get the article though...
THIS is what you are saying we must do on list??? I respectfully disagree - it is several pages of very technical data that would put modellers who just want to run trains off in droves when the "useful answer" is:
(1) don't make a ring main
and
(2) add a resistor+ capacitor across the ends of the bus to suppress voltage spikes and assist maintenance of good CC signal.
So...
I maintain that the backgound of such issues is actually totally irrelevant as long as they are founded in fact and they work - just as a modeller does NOT need to know how his loco's motor works or how his DCC system knows which loco is which. I can say with absolute confidence that all the things recommended ARE based on fact and DO contribute to better layout performance - so any layout created with the guidelines expounded earlier in the thread WILL work well and reliably..
So - in fact, my general answer is "Nope - it doesn't really matter - and most definately it is of no interest to the modeller whose layout is fixed and not to the one who follows advice and avoids problems.
Surely... If we can give a simple set of instructions that when combined will sort the problem, then that is all that matters.
Kind regards
Richard
DCCconcepts