Fitting Sound To The Heljan PWM Shunter
Start by removing the two plastic parts which cover the screws. There are only 2 screws for the body, both at the front.
The model has a next18 socket and a built in speaker enclosure. (We didn't use the enclosure).
We used a 15x11 speaker with a self adhesive gasket and stuck it straight onto the flat part of the PCB to form an air tight seal. Heljan provide 2 speaker wires, these have to be soldered onto the speaker.
We also took some detail out of the cab (a seat and a box) and fitted a stay alive. This helps the running massively. A little bit of plastic needs to be filed away so that you can get the wires through to the decoder.
Once the body is back on the stay alive is well hidden.