I have a Bachmann 2-8-4 with DCC on board non sound and want to replace the decoder with a Tsunami sound decoder
I was hoping it was a matter of removing the Bachmann decoder and replacing it with the Soundtrax and hooking up a speaker
The Sondtrax comes with a heat shrunk module shield that the directions state not to remove
Anybody do a similar replacement and can offer some advice
Here are pics
51% share holder in the ME&O ( Wife owns the other 49% )
ME&O
Solder the leads to a 8 pin NMRA plug and plug in. Remove the capacitor or capacitors from the PC board. If you remove the PC board, use a 1 k resistor if the loco uses a LED headlight.
By the way, it is SoundTraxx. Speaker install will be another issue.
Below is a link to the Bachmann Spectrum diagrams. Look for a diagram of a sound loco that is close to your 2-8-4 tender to see possible speaker install ideas.
http://www.bachmanntrains.com/home-usa/references_2010.php
SoundTraxx does allow the shrink to be cut back just enough to remove the 9 pin JST connector. You can buy a 9 pin JSI connector to 8 pin NMRA connector. Litchfield Station sells the adapter and can make suggestions. They have for me.
http://www.litchfieldstation.com/DCC-University/index.htm
You will have to cut the weights into smaller pieces of use bird shot that you can get at gun shops.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
"SoundTraxx does allow the shrink to be cut back just enough to remove the 9 pin JST connector. You can buy a 9 pin JSI connector to 8 pin NMRA connector. Litchfield Station sells the adapter and can make suggestions. They have for me."
I was told the same thing. They people at the hobby shop (Bruce's, Sacramento) where I recently bought my Soundtraxx decoder for a similar installation told me that Soundtraxx will allow you to trim the shrink just enough to access the JST connector without voiding anythng. I used the 9 pin to 8 pin harness from TCS and it worked fine. - Nevin
Thanks for the responses I'll check them out
I would solder the appropriate wires to an 8 pin connector to replace the existing decoder. if those green resistor looking components say L1 and L2 next to them on the board cut them out. The speaker of course will wire directly to the decoder. You'll have to figure a good spot for the speaker but a good spot is usually under the coal load..
Springfield PA
Hamltnblue I would solder the appropriate wires to an 8 pin connector to replace the existing decoder. if those green resistor looking components say L1 and L2 next to them on the board cut them out. The speaker of course will wire directly to the decoder. You'll have to figure a good spot for the speaker but a good spot is usually under the coal load..
L1 and L2 are inductors. Do not cut them out. Remove one or two capacitors near the inductors . You will see C1 and maybe C2. Cut out the one or two capacitors. Depends on what PC board is in the tender.
The two inductors are a moot point without the capacitor/s.
If you do decode to remove the two inductors, solder a short piece of wire in place of the inductors or the motor will nor work. Those two inductors transfer power from the decoder to the motor.
I just changed a bachmanns decoder out and the included instructions come with a yellow sheet that says important notice.
"To prevent damage to locomotives equipped with decoders that do not meet NMRA standards or are not part of Bachmann's E-Z Command line, the suppression capacitors AND inductors (RF chokes) on this locomotive should be removed from the circuit board before non-NMRA decoders are installed.
The note above about soldering a piece of wire to replace the inductors is probably correct. Mine were wired directly to the motor in series with the wiring so it was obvious. These aren't.
Here's the inductors connected to my Acela motor before removal.
Here's the yellow sheet they're packing with the loco's
Not a big deal. This is a well known issue. This has been discussed a lot on the Bachmann forums, the SoundTraxx, NCE, MRC, Digitrax and other forums. On line DCC sellers say the same thing. Hard wire or remove the capacitors. If you want to remove the inductors, solder in a piece of wire.
The big notice by Bachmann is to cover themselves. It does scare the clueless.
If you need more info, do a Google search for bachmann dcc capacitors. I did a search about two years ago and found plenty of links why the inductors and capacitors are in there and how those components affect the loco operation where the decoders have the BEMF capability. Again, do a search before you do a Rant.
How typical. They put an LC circuit in their locos that kills high frequency drive pulses and interferes with BEMF and then claim it's the DECODER'S fault for not being NMRA compliant. While conveniently their decoders don't use high frequency drive and don't have BEMF. I think their chickens are coming home to roost with the newer sound locos using Tsunamis - look at allt eh adjustments needed to the BEMF settings to get them to run well - or just, you know, remove the unecessary junk from the circuit. Or are they going to claim Tsunamis are also not NMRA compliant?
Sort of like the ones that need the 1K resistor on the program track to work with most systems. Somehow all those different DCC systems are non-compliant and the decoders are. Right. Maybe Bachmann should stop using ancient cheapy Lenz decoders and get with the times. Of course then they couldn't sell a loco with DCC for $50.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Rich,
I wouldnt' call it a rant. An inductor and capacitor basically have the same effect and should be removed, not just because bachmann says so.
The purpose of the devices is to resist the change basically by storing energy and releasing it when there is a change. As Randy noted, this screws up bemf circuits which rely on the feedback to do their job.
How about I just unsolder the wires in the Bachmann harness from the existing circuit board and attach them to the same color code wires on the Tsunami and get rid of the Bachmann circuit board
You could, but in this case the existing board provides connection to the tender harness. It would be easier to keep it IMO.
Shouldn;t be very difficult to cut the wires fromt he Bachmann board one at a tiem and splice them to the approriate decoder wire. It doesn't look liek the colors follow NMRA DCC color codes though, liek if the blue and yellow wires are the ones that controlt eh headlight, well, the headlight should eb blue and WHITE. Yellow is for the backup light, if the tender has one.
It looks very easy to unsolder the connections to the board including the power pickups and splice them into the decoder wires
The tender has a set up for a speaker already in place under the board
That is what I probably what I will do
There are brown green wires for setting functions
Are they for some independent connection to an external source so you can set the decoder before installion