Brush class 47 sound decoder and speaker (8-pin Heljan model)

`OO` variant for Heljan models as this has different motor characteristics to the Bachmann model With the Heljan model please ensure the directional lights are functioning correctly prior to decoder installation. We have found some models where bulbs are creating a `short` which can cause damage to the decoder. Below is a list of the Function keys and their assignments applicable to this model. F0. Lights on/off F1. Sound on/off F2. Horn 1 F3. Horn 2 F4. Horn 3 F5. Buffer up F6. Coupling up F7. Flange squeal F8. Air ‘tick’ F9. Wheel/track ‘groan’ F10. Carriage door slam F11. Guards whistle F12. Shunting mode (half speed) F13. Acceleration/Deceleration. Press once to over ride, press again to cancel. F14. Aux 1 F15. Aux 2