> Paul Vaughn wrote:
> There is no such thing as "DCC friendly <snip>
> the buzz word 'DCC friendly' to sell the new
> products.
Hi Paul...
You are singing a great tune! May I elaborate...
I would opine that the words "DCC friendly" were initiated by someone who
didn't really understand what was going on. In the good olde daze (pre-DCC),
the backsides of wheels would sometimes graze the open point (the point not
pressed against the stock rail) and a momentary short circuit would happen.
With the good old MRC of the past, this momentary short circuit would quickly
disappear as soon as the wheel rolled a fraction of an inch and lost contact
with the point. The inertia of the train/loco/flywheel/MRC simply kept
everything moving right along since the slow-reacting circuit breaker in the
MRC had insufficient time to warm up and shut off the power due to the
momentary short circuit. In fact, these shorts were not even noticed by most
folks at all.
Then along comes DCC and when the momentary short circuit happened, the DCC
solid state circuitry sensed it and shut off the power instantly. And the
common perception at that time was that DCC caused the short. So many folks
actually believed that DCC caused the short that it became widespread common
knowledge even though it was totally incorrect. Very few folks had any
interest in admitting their track and wheels were out of gauge and short
circuiting each other. Why put egg on your face if there is a different way to
save face?
Eventually the practice of isolating the frog from the rest of the turnout in
order that the point polarity could be permanently "connected" to the adjacent
stock rail became a popular solution. Again, hardly anybody ever bothered to
check the gauge of the wheels and track. Just too much trouble. With this
so-called "fix" (which merely masked the symptoms), the term "DCC friendly"
became popular and synonomous with an isolated frog and permanent connected
point polarity. With this so-called "fix" the wheels could still graze the
point, but there would be no short circuit.
Then the turnout marketing boys stretched the truth a bit by implying you had
to have DCC-friendly turnouts in order to operate with DCC. This, of course,
is absolutely untrue, but good salesmen never let truth get in the way of
making a sale. (Buy your gondola from me!) So the term became even more
widespread through advertising and product reviews by those who should have
known better, but didn't.
Which brings us up to today wherein you have just seen two fellows both claim
you need DCC-friendly turnouts and isolated frogs in order to operate with DCC.
TOTAL HOGWASH !! The mighty NYC and many other model railroads operate with
DCC and conventional turnouts that do not have isolated frogs or tied-polarity
points. These layouts do, however, have owners who check the gauge of all
wheelsets and correct them as needed. And they also check the gauge of all
turnouts and correct them as needed. And they also have a very high degree of
troublefree operation. Just like the real railroads.
How about if we end the DCC-friendly myth (at least on this List), stick to the
facts, check the wheels, check the track and enjoy flawless operation. A lot
more fun I would say.
Off soapbox...Ed L.
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