Has anyboby installed a decoder into a Bachmann Plus 4-8-4? If so, what did you use and did you have to doanything special?? I’m just looking for a basic decoder (like a Digitrax DH123) so I can control the smoke unit. It only has a forward light, so a simple decoder would work. Could you let me know? Thanks!
I can’t answer your question, but I have a concern. Any idea how much power the smoke unit requires? It could wind up being a decoder eater.
Adelie,
Ya know what? I never thought of that. I’ll look into it.
There’s enough room in the tender that you could probably install a small reed relay to turn the smoke unit on and off, which would be controled by one of the function outputs… Then use track power through the relay to operate the smoke unit… Remember though that most decoder output ratings are AT track power… That is, 15 volts 300ma (or whatever it happens to be), not the 1.5v we step our lighting outputs down to with resistors. Also remember that a smoke unit is electrically a light bulb… That is, a thin wire that heats up. To be completely safe though, disconnect the motor, set the loco on the track and power it up and check how much current it draws.
As for the decoder itself, if you want to put it in the loco chassis, you’ll probably have to mill out some of the metal… Aren’t those full metal chassis??
Good luck,
Jeff
You definently want to put the decoder in the tender. I agree with the advice on checking the current draw on the smoke unit if you will be running it off the decoder, but my question is. Why run it off the decoder? Have the smoke unit connected right to track power. If you want the ability to turn it on and off, a reed switch would work, but I would mount it in the cab or locomotive itself. Its not the best idea to get magnets very close to decoders. They tend to get a severe case of amnesia. If you are considering a DH123, I would suggest a TCS T1. They are the same price, same size and design, but the engineering is a little different. I have had some problems with the DH123 forgetting its programming. The T1 is my staple decoder for my engines. I also usually use a T1 in customer engines too. Unless you dont have room for a T1, you want more than 2 light functions, or you want sound. The T1 is great.
I installed a decoder into one for a club member, but will never attempt that again. The locomotive frame must be taken apart in order to isolate the motor because it has bronze wipers that press against the insides of the frame halves for electrical pickup, and in order to disassemble the frame, the side rods and wheels must all be removed.
A cavity then had to be ground out on top of the frame to make room for the decoder.
Installing a decoder into the tender would require even more work because you would then need to have at least 4 wires between the tender and locomotive. The tender does not have electrical pickup, so 2 wires would have to go from the locomotive to the decoder, and 2 more wires from the decoder to the motor. If you wanted to control the headlight with the decoder, add 2 more wires. And for the smoke, if you want to retain that, yet 2 more wires.
The headlight is very difficult to replace because of the way it is mounted into the frame, and the smoke generator uses heater wire that is difficult to solder.
I was hoping that Bachmann would be releasing a Spectrum version of the GS-4, but the latest news from their web site is that it will be another Plus model, with no mention of DCC compatiblity.
Sorry, I was away for a couple of days. Thank you all who answered and after reading Cacole’s reply, I may just use it DC. It’ll still do what I want, I just wanted as many loco’s DCC as possible. This may be more then it’s worth for what I want it to do! Thank’s again all!
If you don’t use the decoder to control the smoke unit - you DEFINITELY want some kind of switch - running the smoke generator at full DCC voltage (consider when running on DC it usuall only running at HALF power - 6-8 volts, since you don;t run at full throttle all the time) with no fluid in it will quickly burn it out. I’m not a big fan of smoke anyway, since it seldom looks realistic, and leaves residues all over the layout when it settles. You definitely need to be able to turn it off though, especially if powerd right from the rails - anytime track power is on, it will smoke, and smoke a lot.
If a relay is connected to a function output, you also need an ordinary 1N4001 diode connected in reverse across the relay coil - cathode (the flat banded side) to the blue wire, to absorb the spike generated when the relay is released and protect the function output on the decoder.
–Randy