NSW NR Class

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NR Class – Decoder Installs

This is the second release of the NR class by Austrains and this time consideration has been given to installing a sound decoder and speaker as well as a good light selection.

This page will show you how to install a Tsunami AT1000 GE sound decoder and a reasonable speaker.

Once the shell is removed, you will see the light board at the rear of the chassis. Remove the board and snip all the wires as close as possible to the board. The two mounting pillars can be ground off so as not to short on the underside of the decoder. I used a length of 1mm thick double-sided tape to mount the decoder.
This photo shows the wiring above the board, all the wires in the loco have the correct colour code so re-attaching them to the decoder is straightforward. Just be VERY careful how you solder – no dags or shorts.

Run the wires from below the board up through the holes in the middle, there is no room for them to run around the board.

The black heat shrink tubing covers the 1k 1/4 watt resistors for the LEDs at the front and the rear.
There is a cast hole at the front of the chassis for a small oval speaker but there is no room to build an enclosure around it.

This makes it very quiet and not worth fitting a sound decoder. BUT, there is plenty of room in the fuel tank as shown here. Remove the two slide switches and their wires you will be able to control the lights from the decoder.
You will need to make a gasket to go between the speaker and the bottom of the tank so the cone of the speaker does not hit it and distort the sound. I used 0.5 mm styrene for this as shown . Leave room around the gasket to fit up into the the bottom of the chassis.

Drill some 3mm holes in the bottom of the tank to allow the sound “to get out”, then cover the bottom of the tank with something to keep the dirt out. I use a small piece of material cut from old pantyhose.
The loco comes with a number of light options. This photo shows the headlight and white marker lights above the windscreen. The light board above the cab is mounted on the chassis and has two blue wires, a white wire and a yellow wire.

Join the two blues together and solder to the “common” connection on the front of the decoder. The white wire is connected to the “Headlight Connection” on the decoder through a 1k 1/4 watt resistor.
This photo shows the two red markers when the loco is in reverse. (They do not show as “red” in the photo). The yellow wire from the front light board is connected to the “backup light” connection at the rear of the decoder, through a 1k 1/4 watt resistor.

The wires from the light board at the rear of the loco are connected in a similar manner, the yellow to the rear of the board and the white to the front of the board. Remember to fit a resistor to each wire.

This photo shows the lower marker lights (Ditch Lights). The blue wire from the front is attached to the common with the other blue wires. The white wire from the front is attached to the pad marked “F6” on the decoder through a 1k 1/4 watt resistor.

The yellow wire from the rear ditch lights goes to the “F5” pad on the decoder.

The “F5” pad is remapped to “F1” and the “F6” pad is remapped to “F3”. This will allow individual control of the Ditch Lights.
This photo shows the connection points on the decoder and how they are connected to the LEDs. The blue box on the wire is the 1k 1/4 watt resistor – one for each LED.

The RED wires go to the right hand rail and the BLACK wires go to the left hand rail.

CVs to be changed

Decoder Pro

Download and save NR Class your Decoder Pro Roster. In Decorder Pro, run “Recreate Roster” then you can use it to program your loco NR_109.xml

Download NR_109 pdf if you do not have Decoder Pro. It is a single page pdf – the CVs you need to change are highlighted in yellow.