How to convert Graham Farish Duchess Class 46229 (1816) to DCC

This guide covers the following models:

• Duchess Class 46229 'Duchess of Hamilton' in BR maroon (1816, 372-178)
• Duchess Class 46245 'City of London' in BR lined green (370-100)
• Class 8P Coronation 6234 'Duchess of Abercorn' in BR lined green (372-176)

Digihat Conversion

This conversion follows the Graham Farish insulating bush (Digihat) method to isolate the lower motor connection from the chassis. The best place to fit the decoder is in the tender. The tender also has track pickups, via a single black wire and the brass connecting bar between the tender and the loco. Be careful to make sure the metal parts inside the tender are isolated and cannot contact any part of the decoder, or any exposed bare wire ends.

In this conversion, the customer required the decoder to be easily removable, hence the use of a 6-pin harness in the tender instead of the hard wired decoders normally used.

Optional Step - Tender Pickup Modification

There is an additional modification that can be made to this model, which improves the pickup reliability and therefore DCC performance. This requires replacing the plastic part in the tender that the rearmost screw goes into with a metal nut. This will provide a good power connection to the other rail - the one which is connected electrically to the loco via the drawbar. From the factory, the tender only has easy access to one track pickup via the centre screw, this is the one that ordinarily connects to the loco via a black wire. You may find it easier to replace the screw at the same time, if the correctly-sized nut cannot be sourced.