I’m looking to add this decoder to the climax and was checking to see if anyone has already installed this decoder. If so, any suggestions and where would be the best location for the speaker?
Thanks a bunch,
Doug
I use the Micro-Tsunami logging decoder in a MDC Climax. Tight fit.
You will have a good chance of doing this. I looked at the parts diagram for the Spectrum Climax and there looks like a spot under the PC board in the tender for a speaker. I see holes for the sound in the parts diagram. The decoder would have to be stuffed in on top of the PC board. Just a guess. You would need a 8 pin NMRA connector and solder the decoder wires to the appropriate pins. Might even have to remove the PC board and hard wire. I just do not know since I have not seen this loco up close. Bruce at Litchfield Station would no doubt have a suggestion.
If you do this, clip the capacitor on the PC board. There might be two capacitors right next to each other. They affect the operation of the decoder.
Follow the NMRA DCC standards and the decoder comes with wiring instructions.
Rich
I do believe the original intention of Bachmann was to allow for a space for a drop in light board replacement (like the old 2-8-0 Soundtraxx LC conversion), but as it stands, there is too much going on underneath the light board (wires mostly) to allow for a speaker to fit (note that shorting the bottom of the light board with the speaker is a great way to let out the magic smoke).
I have done many of these conversions, and I find the best way is to snip and mark the wires (they are all black…geesh) and hardwire the decoder in (the wires are marked on the light board). Remember to remove as much heatshrink around the edges of the TSU-750 as possible to allow for a good fit of the decoder. Use a speaker with a styrene stand off on the floor of the coal box (there is a screw there for the rear truck that will interfere with the cone of the speaker…so fabricate a stand off with styrene to avoid destroying your speaker quickly).
Careful with the lights as they are LEDs. You will need to put a resistor inline with the white and yellow leads to avoid blowing them (560ohm or higher works well).
Finally, complete the box by fabricating a sheet of styrene to fit just beneth the top of the coal box. IIRC, you will have to cut a few nubs off of the coal/oil load to allow it to not interfere with the styrene. The better you seal the box in this stage, the better the sound will be.
Because of the small speaker, you will need to adjust the equalizer to suit it.
Hope this helps.
David B
I see the two capacitors. Clipping these will not break the circuit that was designed for this PC board?
Thanks,
Doug
Careful with the lights as they are LEDs. You will need to put a resistor inline with the white and yellow leads to avoid blowing them (560ohm or higher works well).
Regarding this comment, what is keeping them from blowing prior to a decoder being installed?
Thanks,
Doug
There should be resistors on the board. I always err on the side of caution…nothing worse than having to open up a detailed steamer to replace LEDs.
Meothod 1…Install resistors inline with the white and yellow leads. If you dont have lights, then reverse your connection first (+ive to -ive). If that doesnt do it, then remove the resistor.
My Meothod… have an LED tester. It saves me any guess work.
David B
My experience with the 4-4-0 is a resistor and a diode in the LED leads. The 4-6-0 had three resistors and a diode in series with the LED leads. The 44 ton has 12 volt leads so no resistors. The USRA medium tender has no resistor for the headlight but does have a diode in series with the headlight lead. The PC board had a small value resistor to dim the headlight for reverse operation. The diodes drop the voltage 0.7 volts which is not an issue. I have traced out the PC boards.
Again, Bachmann has production changes and the user might not be aware of this.
Rich