EMC 103/103A DCC PT1


I labelled each chassis with the respective road numbers for ease of identification.  The DCC install is pretty simple….

The motor wiring was redone with orange and grey 32 Gauge wires from NCE.  These connections were reinforced with my usual application of liquid connector coating.  A small drop of 10 weight Nano oil was applied to the motor shaft bearings.  Then the motor assembly was installed in the chassis, the trucks mounted, the universal shaft/worm gear (with an application of Nano Grease) and truck retainers snapped on.


Following this I soldered a 1/4 Watt 680 Ohm resistor directly to the decoder “-“ lighting tab (cathode side) for LED connection.  I then inserted the decoder, a PNP or board style, on top of the motor mounts and held it in place to the chassis weight with Kapton tape.  The motor wires were soldered to the decoder motor tabs.


After this I worked from front to rear on each section.  The leading truck track pick-up wires were soldered to the appropriate decoder tabs.  Next, I soldered the headlight leads white ( “-“ cathode) to the aforementioned resistor and blue ( “+” anode) to the other decoder tab.  I attached the cab interior to the chassis using double-sided tape.

The rear truck pick-up wires were soldered to the pick-up tabs at the rear of the decoder, however a second wire was included at each tab going to a Soundtraxx 2-pin connector (between the sections).  Although it is easy to see the orientation with respect to the red and black wires, to further help ensure proper track polarity when the connector is assembled, I painted one side of it yellow (as seen below).


I then assembled the 28mm speaker assemblies, soldering the wiring onto the Soundtraxx speakers and inserting them into the enclosures.  They are mounted to the chassis using double-sided tape.  I am using a Miniatronics 2-pin connector with integral wires between the first and second sections.  Each connector half has a white dot for alignment so they may be assembled in the correct polarity (as seen in the picture above).  One wire also has a white line molded down its length, so keeping the wiring correct is visually easier.  This white-lined lead was designated for the speaker “+” side; the plain black one for “-“ side (the instructions that come with the speaker illustrate which is which).

The two speakers are connected in series; in order for them to work, they must both be connected with proper polarity.

I made the speaker and wheel pick-up wires inside the second section longer than necessary so that I could access the connector when the sections are separated.  The second section wheel pick-up wires were soldered to the mating Soundtraxx 2-pin connector.  As a result, the decoder has all-wheel pick-up and I have found this to be very reliable.  The photos below show the connections with the carbodies mounted.



Next, I was ready to test the two locomotives on my programming track using the layout command station.  First, I tested each one separately using the factory settings including the as-delivered DCC address 3.  EMC 103 sounded and ran very well.  EMC 103A had good motion, but no sound.  After fiddling with the function keys for a while (to make sure that I had started the prime mover and had the mute function off), I felt that there might have been a problem with one of the speakers.

Because the two speakers are connected in series, if one doesn’t work, they both don’t work.  I made a jumper connector (pictured below) and connected it to the first section speaker.  It didn’t work, so the trouble was with that speaker.  At the bench I made a continuity check and the speaker was dead.  So I replaced it with another new one and that fixed the trouble.


With both locomotives, I was able to use all light and sound functions and they both ran smoothly right out of the bag.  Whatta relief!

FT Tidbit:  Some railroads, like the Lehigh Valley, employed the Model F/FT in helper service.  Why use a glamour girl like the Model F in helper service?  For purely economic reasons: a four-unit FT could replace as many as four steam locomotives then used as helpers.  This meant reducing the manpower to run such combinations from 8 crew to 2.  In addition, FT’s were more self-sustaining in that they did not need as many or as intense inspections and routine maintenance as steam did.  They could operate longer before needing to be refuelled, so they were well suited to remote helper bases.  And the diesel strength, starting tractive effort, was just what the job called for.