Hornby Class 43 HST DCC decoder installation guide
This guide is designed to help you with the installation of an R8249 or TTS Sound decoder with Class 43 HST models. Please note that your model may not be exactly the same as the model used in this guide, and it is representative only.
As with all modifications, these are carried out at the owners risk and we cannot accept any responsibility for any damage caused.
Carefully remove the body by gently pulling the body sides apart and then pulling the rear of the power car down. You can refer to your locomotive service sheet for further guidance.
Locate the motor at the rear of the power car. It will have red and black wires going to it from both the front and rear of the chassis.
Unsolder the red and black wires where they are connected to the motor and capacitor. Do not cut the wires any shorter as they will be needed when installing the decoder.
Remove the decoder from the protective packaging, taking care not to handle the PCB directly as this will cause irreparable damage due to static electricity.
It is important to protect the decoder by wrapping the PCB with insulating tape. To prepare the decoder, remove the plug and separate the red, black, orange and grey wires. The rest can but cut short and insulated. Strip the red, black, orange and grey wires and lightly “tin” them with solder. Tinning the wires will make the installation easier.
Soldering in the chip is fairly straight-forward. Solder together the 2 black wires from the wheel pickups to the black wires from the decoder.
Similarly solder together the 2 red wires from the wheel pickups to the red wire from the decoder. The orange and grey wires from the decoder are then simply soldered to the capacitor legs as shown. The decoder can then be attached on to the lead weight using insulating tape. It is recommended that all solder joints are wrapped with insulating tape.
Once the decoder is secured, place the locomotive on the programming track and test to make sure that the installation has been successful.
Remember that the decoder has a default number of “3” and it is recommended that you code the locomotive to the number you require and test again. Also test that the wires and decoder cannot become caught or trapped by the gears of the motor bogie during operation.
Carefully replace the body onto the chassis taking care not to trap any wires during this procedure. Test once more to ensure that the installation has been totally successful.