Heljan Class 11 Sound And Stay Alive Fitting
These models are quite easy to fit sound to, using the next18 decoder and built in speaker, but I made some further improvements to the model to improve the sound and performance.
Start by pulling off the black battery box covers, and remove the screw at each side, and pull the pipe out near the front steps, which runs to the front lights or it will get damaged. Use a prising tool to help get the body off, there are clips at the front and rear, the whole lot lifts off, including the cab.
If you want to keep the install as easy as possible you can just add the decoder, theres already a built in speaker, but its also possible to improve the speaker and add a stay alive.
I used a Train-o-matic SPP-N but I had to cut the capacitor off and extend the wires. make sure you connect the capacitor back up the same way round! I then put the capacitor behind the nose and the board under the main PCB.
The insulate the board for the stay alive with kapton tape. It's about 1mm too thick so the clips that hold the PCB no longer hold it, so I used 2 lengths of kapton tape to hold it, clearance isn't an issue and the body still fits fine.
I finished it off with a 20x14x4 speaker, soldered to the same terminals as the original speaker I took out. This is about twice as loud and has a much deeper sound.
I thought I was finished but all the lights came on together, I like them to be directional so that I can easily see which way the model is gonna move, so I looked at the PCB and noticed that there was a green wire bridging two components, which looked like a bit of an after thought, so i took it off, and it made the lights directional, but backwards! So I have reversed the light outputs in the function mapping and it works now, any decoders you buy from us will already have this change made.
Find the decoder here