Proto 2000 GP9

The long awaited Revolution A (Atlas Light board) style decoder works just fine in this loco. The locomotive was disassembled. A belt sander was used to cut the weight down to level right at the highest point on the motor. The black plastic covers were removed from behind the two rear most fan grilles. The rear light pipe was removed and cut down to clear the speaker. A drop of Faller Expert styrene cement on the machined end of the light pipe gets rid of the scratches quicker than all the polishing you can imagine!

The speaker was installed in the shell and connected to the two-pin connector MALE side.The speaker was sealed to the shell with bathtub caulk. The decoder was installed with the LEDs wired with the anode to one rail and returned to the function pad with a 750 ohm series resistor. The capacitor is secured above the front truck with double sided tape.


For those of you who have attended Bruce's clinics on "How do I get the sound out?" will recognize the technique: The positive pressure goes out the grilles and the negative pressure gets routed mostly to the front truck. Here is a detailed photo of the speaker mount.


An alternative speaker mount is shown below, with a speaker and enclosure combination replacing the cab details. While this is a more conventional mount, the sound quality is SIGNIFICANTLY POORER than with the grille mount shown above.


We did this install before the TSU-AT1000 Atlas light board version of the SoundTraxx Tsunami was available. In 2009, we would use that decoder for four reasons - lower price, more accurate sound, easier light connections and programming without using indexed CVs. The LEDs would be wired between the lighting pads on the board, not to one rail!

Copyright © Bruce F. Petrarca 2007 - 2018; All Rights Reserved