How to convert Minitrix Class 9F Evening Star to DCC

This guide covers the following models:

• Minitrix 9F 92018 BR Black (N207)
• Minitrix 9F 92220 'Evening Star' BR Green (N209)

Step 1 - Remove body

Remove the loco body by unscrewing the screw in the top, then gently pulling upwards. Remove the weight.

Step 2 - Remove PCB

Remove the screw holding the PCB in place. Desolder the copper tabs, green wire, red wire and black wire from the PCB. Remove the PCB.

Pull the black wire (from the tender) back through the hole in the back of the loco's motor bay, and instead thread it through the corresponding hole at the other side.

Solder the black wire to the copper tab just between the second and third wheels. At this point, you can add another tender pickup for the other rail if you wish, this can help running reliability and reduces the reliance on the tender draw bar to provide and electrical connection. Conveniently, there is a spare hole behind the motor to pass the wire through.

Step 3 - Modify track pickups

Snip off the top of the copper tabs so they are only just slightly taller than the top of the red cog.

Step 4 - Modify bulb holder

Remove the screw keeping the bulb holder in place. Remove the bulb and the holder.

Cut a notch out of the bottom rear part of the bulb holder, the light wire from the decoder will enter through here.

Cut off the contact that was previously pushing against the back of the bulb. The easiest way to do this, is to score across where you want to remove the metal, and then use tweezers to bend it back and forth until it snaps off.

Step 5 - Modify bulb wiring

Solder a white wire to the tip of the bulb, and a blue wire to the outer edge. Apply some shrink sleeving.

Thread the wires through the notch you previously made in the bulb holder. Re-seat the bulb holder and bulb. Refit the screw.

Step 6 - Modify motor wiring

Desolder the red and green wires from the motor. Remove the motor by unscrewing the two screws at the back of the motor bay holding it in.

Add some kapton tape around the sprung contact at the bottom of the motor, so that when refitted it can no longer make electrical contact with the chassis.

Refit the motor, and replace the two screws holding it in.

Step 7 - Connect the decoder

Position the decoder on the pillar which originally held the stock PCB. Add some tape so it cannot come into contact with any part of the chassis. Use black tack to secure the decoder to the pillar.

Solder the red and black wires to the shortened tabs, and add a piece of heat shrink sleeve over each so it cannot touch the chassis pillar.

Solder the orange and grey wires from the decoder to the motor terminals.

Refit the front weight, and route the white and blue wires up and over it. Space is very tight in this area when the body is refitted, so very thin wire is needed. Solder the white and blue wires to the decoder.

At this point, test that the decoder can control the motor and the front light using your programming track.

Step 8 - Refit body

Replace the body, and the screw and the conversion is complete.

Step 9 - Light function programming (optional)

By default, the front light will be illuminated when driving forwards only. You may want to modify the function programming on your decoder so that the light is also illuminated when the loco is moving backwards.

Consult your decoder manaual for details, e.g. for Lenz Silver Mini+ you need to set CV33 = 3 and CV34 = 3.