PC: MU Compatability

["Price" <eprice@xxxxxxxxxxxx>]

Hi All,
  Couldn't help but notice Garret Rea's Mu Computability statement about the
C-628.
  Several things factor into MUing various manufactures locos with each
other.
  1.  Gearing
  2.  Motor Speed
  3.  Electronic circuits(bio directional lights, light bulbs, decoder
plugs, etc) all add resistance to the circuit, which in turn slows down the
loco.
  4.  Lack of nickel silver wheels.  This applies to athearn and some of the
early P2k.  These manufacturers use/used either sintered iron or brass
wheels.  These wheels pick-up dirt much faster that nickel silver wheels
which in turn will disrupt a good electrical circuit.
  5.  Motor quality and fly wheel quality(Noteabably athearn)  I was curious
as why the P2k motors seemed to be better than an athearn as they appeared
to be identical.  A friend of mine who owns a machine and turning shop put
an athearn motor to some precision micrometers.  We found out that the
flywheels are not turned true.  The flywheels miced out  as a measurement
for standard stock which is not machined hence truely round to machine
standards.   Apparently who ever produces this for athearn simply drilled a
whole near center and bored out the other end for the flywheel coupling.
Slop in the armature was evident and the list goes on and on.  I decided to
scrap the athearn motors and replace them with can motors from A-line.  My
buddy produced some flywheels for these motors but A-line also produces
them.  The moral of the story is there is a reason why an Athearn cost
around $30 and a Kato $100 plus.
  Any way, I had to come up with a solution to getting all of these locos to
mu with each other.  (repowered athaern, kato. atlas-china, P2k, front
Range, Alco models brass and Bachman)
  I found that by adding resistors to some of these I could get ALL
locos(except Atlas-Roco) to mu with each other.  There is about a 30 ohms
difference between them all.  I installed 1/2 watt resistors from radio
shack between the electrical pick-up and the motor.  These resistors have a
high defect rate but are only 50 cents a package.  Also these things do get
hot so make sure that they do not touch the plastic shell.
  I'm not sure as how this will effect DCC as I run my stuff on a layout
which is standard DC block control.
                                      Hope this helps
                                          Ed