Looking to convert two Bachmann GP-40's from DC to DCC. Thinking I should make one with sound and the other not. What decoders should I use? Should I replace the light board or remove altogether? Just seeing what would fit inside fairly easily. I have a Dremel to do some minor modifing. I know I might not ba able to comment back right away, been lurking for sometime, but will looking at post either way.
Thanks in advance.
Dan
Get in a few more posts and you will lose your moderation status.
Is that a plug on the right of the circuit board? Either way I would get rid of it.
Maybe a sugar cube speaker would fit above one of the trucks. TCS shows a speaker on top the frame, see link below. I would also replace the light bulb with a 3mm warm white LED. Depending on whose DCC board you use, you may or may not need a 1k resistor.
Here is a link to a GP50 installation
I don't know if you have that much room above the frame.
Unless you want to consist these two engines, I don't understand why you want one sound and one not. Why not install sound first and see if you like it. Some people do, some do not. Also, the sound output from most DCC boards is unpleasantly loud and in some cases may over power the speaker.
Henry
COB Potomac & Northern
Shenandoah Valley
Hello All,
I've converted a number of Bachmann GP40s from DC to DCC- -all non-sound- -and re-motored them in the process while standardizing the decoders.
First, I would remove the shells and see what you are dealing with.
Are they DCC ready?
Do they have LEDs installed on the Original Equipment Manufacturer's (OEM) Printed Circuit Board (PCB)?
I have four (4) GP40s that always run in a consist.
For ease of speed matching I used all the same motors without flywheels, Digitrax DH 166 decoders, and PX 108 Power Extenders; Energy Storage Device (AKA Keep Alive).
Some were DCC ready while others had OEM DCC PCBs. I removed all the boards and hardwired the decoders while adding LED lighting.
Even with motors without flywheels, there's little room under the shell to mount a speaker.
The cavities for the flywheels, above the drive train, could possibly accommodate small speakers running in parallel.
Another option would be to mill out the weight in the gas tank to mount a speaker.
Bachmann makes fuel tank covers with holes drilled in the bottom for sound. These are held in place by screws that you would have to drill and tap into the weight.
Or, you could drill holes in the existing press-fit covers.
As far as decoder choice I've had great experiences with Digitrax non-sound decoders.
I am waiting on delivery of a Digitrax sound decoder for a current upgrade. I've been told there is a delay due to a chip shortage.
On a side note, I have read that the speakers Digitrax uses are sub-par and replacing them with Scale Sound Systems speaker(s) is a big improvement.
Keep the questions coming, let us know of your progress and as always...
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
OP:
I can't help with the sound version, but for the motor-only (non-sound) decoder, it looks like a Soundtrax MC2H104at might be just what you need.
It looks like this (yankeedabbler page shown):
https://yankeedabbler.com/soundtraxx-mc2h104at-dcc-mobile-decoder-74mm-x-17mm-x-3m-scale-ho-part-678-852002/
Yes, you'd remove the existing light board, and drop this in, in its place. These are nice decoders that are very easy to get installed and working. You can either solder the connections, or use those little plastic retainer clips. I'm in the minority, but I prefer using the plastic retainers with the wire leads tinned with solder.
Also, be sure to use some insulating tape between the decoder and the engine weight.
Ok...thanks all for the quick replies. All look at everything, and see where to go from there. Thanks again.