MRH Apr 2011 - Issue 11-04

Page 75

1000 ohm, 1/8 watt current limiting resistor for LED under heat shrink tubing

Putting a GP7 into service Reader Feedback (click here)

by Charlie Comstock

A

n Atlas GP7 in D&RGW tiger stripes followed me home from my LHS several weeks ago. Finally it was time to put it into service on the Bear Creek and South Jackson. This loco is DCC ready with a NMRA DCC socket on the motherboard. But I had a Digitrax DH165KO replacementmother-board decoder on hand that

Figure 5

fit Atlas diesels so I used that instead of a piggyback decoder. Before starting decoder replacement I checked the gauge of all the wheel sets (figure 2). I carefully pulled the GP7’s shell off, trying hard not to break the delicate handrails (figure 3). The best way to preserve handrail integrity is to pop loose the ends attached to the cab before separating the hood from the frame. This exposed the PC board (figure 4).

clip

PC board brackets

motor leads

Figure 2

trk pwr

NMRA plug

Atlas PC board

Tiny clips hold the wiring in place on the PC board terminals. I used a pair of pliers to remove the clips (figure 5), then removed the board.

trk pwr

to motor

Refer to figure 6. The DH165KO is below the Atlas PC board. The decoder came with four bare wires soldered to the

DH165KO clips

headlight

Figure 6

Figure 3

Figure 1 Page 75 • Issue 11-04 • Apr 2011

• The Engine House - Putting a GP7 on the layout, page 1

Figure 4

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Figure 7

Contents

Figure 8

Index


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