solder button
site map button Intro to DCC

Decoder Installation into an

IHC HO Mikado 2-8-2

This installation note assumes you have read the section on Wiring Specific Locomotives.

This locomotive is easy to install a decoder into.  You can even get the decoder into the boiler and cab area.

The motor is already isolated from the power pick-up and frame in this locomotive.  Three of the driven wheels on each side provide power pick up.  Also, some of the tender wheels are used.  Using conductalube on the back at the power pick of all the wheels' power pick up points is essential with this locomotive.  Also use Conductalube at the swivel points of the tender trucks.

R1 is 22 ohm, 5%, 1/4W resistors.

Use at least a 1A decoder with this locomotive.  A Digitrax DH140 was used for this installation.

Leave the wires to the tender loose they have minimal springiness causing derailments on curves.  You could easily forgo using the tender for power pick up and the rear headlight.

The can motor tightly occupies the firebox area.  I could only get two flickering firebox lamps in.  If you use grain of wheat bulbs, you could probably get four.  I'm happy with the two.  Before assembling the locomotive, drill several holes in the frame so the firebox lights shine down on the track.

Since the motor occupies the the cab, any flickering firebox lights would be very visible in the cab.  You could plug the holes into the floor with the bulbs and then paint the back of the bulbs black.  Or you could use grain of wheat bulbs glued to the bottom of the firebox instead.  Use a resistor about 750 to 820 ohms if you do this instead of the 22 ohm resistor shown.

Be sure you read and understand how the Digitrax keep alive and flash rate is set iforCV 62 in their manual.  Adjust these values to suit your taste.
CV Value Function
01 20 Set to short address 24.
29 02 Set decoder mode to short address.
49 68 Rule 17 Headlight F0f.
50 78 Rule 17 Rear headlight F0r.
51 21 Flickering firebox F1.
62 24 Keep alive brightness (left digit 0-F).  Rate (right digit 0-F).

Though not required reading, you may want to read the section on Hexadecimal Demystified.

Copyright by Allan Gartner 1996 - 2006 © All rights reserved. You may print this for your own, personal, non-commercial use. Non-commercial, non-personal reproduction may be requested by visiting . All users, commercial and non-commercial, may link only to this site at

Thanks to all who contribute to this site and the Q&A forum!