an explanation of terms needed!

[jkroft]

Ok, I've read Allan Gartners wiring for dcc pages, but I'm looking for a few explanations. I'm working with ME's #6 code 70 in n scale, trying to convert to dcc friendly. I understand everything except the part about replacing the throwbar and spring. I assume the throwbar and spring refers to the little bar that connects both point rails (forgive me). If this is so, why must I replace this with circuitboard? Is this just for short protection and as a reliability issue? If I only power the closure rails through the point rails (not soldering them to the stock rails....although I understand why this is a reliability issue) do I need to replace the throwbar? Also, what is the spring to which they refer? It may be different in HO than N, but is it just the little wire "snap" that holds the points one way or another? Last, what is the best way to go about removing, then replacing the throwbar? Has anyone tried Russ Clovers' premade circuitboard throwbars? Thanks
John " I feel so stupid" Roycroft

[rrinker]

The reason for repalcing the throwbar is likely that the original design has both moving point rails tied together electrically. This means it is possible for the back of the wheel on the open side to touch the point rail and cause a short. The receommendation is to use a PC board tie because it is easy to solder the rails to, and you just have to cut through the copper in the middle somewhere to insualte the two rails from one another.
On the other hand, I think this whole "DCC Friendly" thing is blown out of proportion. Yes, DCC reacts FAR quicker to a short, and any short will cause ALL locos in the affected power district to stutter - unlike DC where you have one cab connected to a train and other trains are on different cabs. But at the same time - if your wheels are in gauge and otherwise meet proper standards, and your trackwork does as well, there's not much chance of a problem.
However, fixing things like this AFTER the track is in place and ballasted is nearly impossible. Better to do it prior to laying the track than having to rip things up when a problem is found after it's too late.

--Randy