capacitors in the Spectrum 4-6-0?

[johnnyutah]

[I'm not an electronics person, but cutting a capacitor on a locomotive in the US or Canada does no harm.  Cut them all. ]

How about in Australia? will it be any different? I have very little knowledge on this topic, but I have several Bachmann locos all equiped with decoders (Bachmann). Do not understand when you all talk of an "over speed problem" or "silent" motor drive. I have noticed that my consolidation 2-8-0 does speed dramatically on a steep decent, logicaly this to me is an over speed problem, am I correct. Please people shed your wisdom to this novice!

[NevinW]

I snipped the capacitors and it made no difference that I could observe.  -  Nevin

[Jim Banner]

It seems every 2 or 3 months someone is inventing a better mousetrap. DCC has been around- +10 years? Still no common connectors, plugs, or any thing the modeler might have to tackle in routine use, nevermind customizing. I am sitting on the dcc fence, and will spend no more money on it until everyone get thier ducks in a row....

Tony, that parade of better mouse traps is called "Progress."  Without progress, we would still be paying $100+ for a simple speed/direction/headlight decoder and $1000+ for a simple command station.  As someone who has been involved with multiple locomotive control for 40 odd years, I love it that I can buy a full featured decoder for less than $20, install it in a locomotive that predates "DCC ready" by a decade, and have the whole thing working in less than an hour. 

I thank the NMRA for all their work in making this possible.  But I do not expect them to set standards for every possible little thing.  And I do not expect them to set standards for all the other countries in the world.  I appreciate that they have set a standard for a type of DCC plug, and more important, for basic DCC colour coding.  But I hardly expect them to set standards for tender connections.  If a manufacturer wants to sell after market tenders, he will set his own standards.  But I expect that the number of customers who want to play mix and match with locomotives and tenders is too small to be profitable.  So people wanting odd ball combinations will have to continue making minor wiring alterations to make them work.  But let's face it - changing a plug or two, or hard wiring a tender to a locomotive is not much of a job compared to say scratch building a new tender from the ground up.

As far as everybody getting their ducks in a row, don't hold your breath unless you look good in blue.    It just won't happen as long as manufacturers keep coming up with better ducks.  Twenty-five years ago a friend explained to me that he was going to wait until computers were "perfected" before buying one.  They would be perfected, in his opinion, when they stopped making improvements.  He is still waiting.

Bottom line, don't wait for DCC to be "perfected" before you start enjoying its benefits.   Enjoy it now, even if you have to put up with its foibles and peccadilloes. 

[Jim Banner]

How about in Australia? will it be any different? I have very little knowledge on this topic, but I have several Bachmann locos all equiped with decoders (Bachmann). Do not understand when you all talk of an "over speed problem" or "silent" motor drive...

Australia, like Canada and the US, is sparsely populated.  So radio frequency noise from your trains is very unlikely to interfere with your neighbours' enjoyment of their radios and televisions.  So the capacitors installed in Bachmann locomotives to make them meet codes around the world can safely be removed.

Because their locomotives include these capacitors to suppress radio frequency interference, Bachmann decoders use lower frequency pulses to drive the motors.  These pulses can be heard as a hum or growl in some (many?) Bachmann locomotives.  If the noise is objectionable, silent decoders can be used.  Silent decoders pulse the motor at frequencies above the hearing of most people.  But at these high frequencies, the capacitors conduct appreciable currents and start to short the outputs of the decoders.  The decoders start to shut themselves off to protect their circuitry.  And the locomotive runs erratically.  So with silent decoders, which today is almost all decoders, you have to remove the capacitors for proper decoder operation or you have to adjust them to not be silent decoders.  About 100 out of 100 modellers will choose to remove the capacitors.

Over speed is familiar to every trucker and to most drivers who have ever pulled a large trailer.  When you start moving down a hill, gravity increases your speed.  Your first reaction is to ease up on the gas.  If your speed keeps increasing, particularly past the speed limit, you have an over speed condition.  Note that the speed limit is not necessarily the legal speed limit - it may be the safe limit for your rig under present conditions.  If you cannot reduce your speed or keep it down to the speed limit, you have an over speed problem.  A train is similar.  But with say 120 cars and weighing 12000 tons, a small problem quickly becomes a BIG PROBLEM.  Particularly so if you not only cannot slow the train but cannot even keep it from accelerating.  This is where your life starts flashing before your eyes.

In model railroading terms, "over speed" is often applied to a train going faster than normal down a hill.  It should never occur when there is a hand on the throttle but often does when a train is running mindlessly around a layout with grades.  Personally, I like to see a train struggling up hills and making up a bit of time going down hills, but this effect can be carried too far.  "Too far" might be when the train goes shooting off the rails at a curve - that would definitely be an "over speed problem."  The solution, short of someone actively driving the train, is to use Back EMF control.  Without going into details, this is a sort of cruise control for trains.  Properly adjusted, it can reduce down hill speed and increase up hill speed.  But in my opinion, trying to achieve a constant speed (just like a good cruise control) is non-sense.  Trains in real life rarely have enough horse power to keep their speeds up going up hill.  And the same speed down hill and on the level may not be the best combination to minimize fuel consumption per ton-mile.