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Decoder removal Bachmann Mikado

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Decoder removal Bachmann Mikado
Posted by MECman on Saturday, January 16, 2021 5:26 PM

I have a Bachmann sound value 2-8-2 pulling freights on my MEC layout. I'm a dinosaur who still uses DC for control for a variety of reasons. The loco works fine in DC, but honestly, I find the sound annoying. How does one dissasemble this model to remove the decoder and will this be an easy task? If I remove it, will the engine run fine witout any other changes?

Thanks,

David

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Posted by Trainman440 on Saturday, January 16, 2021 6:52 PM

Alternatively, you can just cut one of the speaker wires, which will silence the engine. But be aware that reverting your changes will require you to resolder that wire. 

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Posted by ATLANTIC CENTRAL on Saturday, January 16, 2021 7:05 PM

Trainman440

Hi! Sorry for the late response. If you want to remove the decoder, that's fine, just unplug the 8 pin socket in the tender (google NMRA 8 pin to get a reference as to what it looks like), and replace it with a dummy DC plug which should be included in the box in a little baggie. 

To get inside the tender, there should be one screw on the centerline toward the front on the bottom of the tender. (Dont remove the screws holding the trucks on!). Then lift the shell from the front, and unlatch the two plastic clips near the back of the tender.

Hopefully this helps!

Charles

 

I could be wrong, but it is my understanding that the Bachmann sound and value locos do not have seperate lighting boards and decoders connected with 8 pin plugs?

Have you had one apart to see otherwise?

Sheldon

    

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Posted by Overmod on Saturday, January 16, 2021 7:22 PM

ATLANTIC CENTRAL
... it is my understanding that the Bachmann sound and value locos do not have separate lighting boards and decoders connected with 8 pin plugs?

If that is so, then cutting or desoldering and insulating the one speaker wire becomes a compelling way to accomplish the desired effect.

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Posted by ATLANTIC CENTRAL on Saturday, January 16, 2021 11:29 PM

richg1998

You can find the loco diagram easily enough at the Bachmann site. Just Google Bachmann forums. It will pop right up.

You can also turn all sounds to zero. A the CV last there also. I will let you find it.

Rich

 

Bachmann's parts diagrams do not give any electrical details, but the tender parts diagram sure looks like there is only one circuit board with an intergrated sound decoder.

As a DC operator using Aristo Train Engineer throttles, I remove all decoders because they will not work with the PWM output from the Train Engineer.

I have not yet had occasion to purchase a Sound and Value loco and see what will be required to make it straight DC. But I suspect it will require removing the circuit board and rewiring the lights. OR, salvaging spare lighting boards, which I have a few of in surplus DC Bachmann tenders.

Sheldon

    

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Posted by mbinsewi on Sunday, January 17, 2021 9:44 AM

I guess I'm not understanding what the OP has.

So, this is a "DCC ready" (no decoder installed) loco, with sound that works on DC ?

Mike.

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Posted by rrebell on Sunday, January 17, 2021 10:05 AM

mbinsewi

I guess I'm not understanding what the OP has.

So, this is a "DCC ready" (no decoder installed) loco, with sound that works on DC ?

Mike.

 

No he has a sound value Bachmann.

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Posted by Trainman440 on Sunday, January 17, 2021 10:07 AM

My apologies, I assumed it had a similar tender to the 2-8-0 or 4-8-2. Couldnt find any exploded diagrams of this online. 

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Posted by BigDaddy on Sunday, January 17, 2021 10:21 AM

I just looked at the review on MRVP and it looks like the lights are directional.  You will lose that if you just rip out the decoder. 

People have repeated posted in the past, that the sound on start up cannot be disabled on startup via CV's  

I don't know if the video is free or only for members.  I an unable to sign out of MRVP to check.  It doesn't show the decoder.  Sound value does have sound on DC.

Henry

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Posted by Overmod on Sunday, January 17, 2021 11:31 AM

If he wants 'sound on demand' he could install a simple switch accessible through or under the bottom of the tender, and wire one of the speaker leads to it.  Or install a two-pin 'computer' jumper connector like the kind used to set IDE hard drives.

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Posted by ATLANTIC CENTRAL on Sunday, January 17, 2021 12:14 PM

mbinsewi

 

 
rrebell
No he has a sound value Bachmann.

 

OK, I had to look that up.  I get it.

I found a Sound Value Decoder Quick start guide, and it says F8 mutes everything.

I suppose since he's running in DC, his throttle doesn't have function keys.

Just trying to understand this all.

Mike.

 

Mike, it is a DCC loco with sound and a dual mode decoder that works on DC. But, on DC you do not have control of the sounds and you have no function keys to mute the sound.

The decoder and lighting is I suspect all one circuit board, so converting it to true DC without sound means removing the circuit board and rewiring the lights yourself.

Clipping the speaker wire will stop the sound, but the decoder will still require a high throttle position before the loco moves.

If the OP is sure he is not switching to DCC any time soon, and does not want sound, rewiring the loco to eliminate the decoder with give the best throttle performance on DC.

Like all decoders, the sound and value instructions warn against using the decoder with advanced DC throttles with pulse or PWM control.

Sheldon

    

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Posted by rrinker on Sunday, January 17, 2021 12:25 PM

 If unsure about future DCC use, just be careful in removing the board - leave enough lead length to allow the decoder board to be reconnected, or unsolder the wires right from the board itself - after noting carefully where they go. Then it will be a fairly simple job to reinstall it if in the future, the OP converts to DCC. 

 Plenty of reason to completely remove the decoder if using DC. There's Sheldon's issue with PWM throttles confusing the heck out of the decoder and it's automatic switching between DC and DCC, and then there is the simple fact that the same loco as pure DC may start moving at 2 volts, while the loco with the decoder isn't going to move until 5-6 volts are on the rails, maybe more. So much for doubleheading a pair of them if one has a decoder and the other doesn't. 

                         --Randy

 


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Posted by mbinsewi on Sunday, January 17, 2021 1:15 PM

If the OP removes the decoder/board completely, what will have to be done so it runs on DC ?

I mean, after he removes it, he'll have a tender full of wires.  Whats next?

Mike.

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Posted by rrinker on Sunday, January 17, 2021 1:45 PM

 Pickups from one side get tied to one side of the motor, pickups fromt he other side get tied tot he other side of the motor. That's enought o make it run. Lights can get tricky, depends if they are LEDs or incandescent. If LEDs, a resistor is probably required, and a little trial and error to figure out which wire is which so that when the loco moves forward, the front LED is the correct polairty to light the headlight,m and the backup light goes on when the loco is backing up. If the lights are incandescent, and 12-16V, they just get hooked up to track power, but then will be on all the time the loco is running - might want to only hook up the headlight.

                                    --Randy

 


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Posted by Overmod on Sunday, January 17, 2021 1:52 PM

I believe the consensus, such as it is, on Sound Value decoders is that they have the LED lighting resistors built into them, and that any 'light' wires therefore need 1K resistors put in circuit with them if the decoder is removed.

I don't think it's worth removing the decoder and retrofitting some light board if all he's concerned about is sound.  Wouldn't it work fine to put a switch for the motor lead(s) in, too?

Someone with the appropriate software: what if he used one of those now-infamous DPDT switches in the tender, with the sound wire being switched between DCC and "off" (perhaps null) for DC,  and the hot motor lead doubled and switched between continuity in DC and connection to decoder in DCC (with full disconnection between)?

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Posted by rrinker on Sunday, January 17, 2021 2:05 PM

 You need a few more poles than a DPDT switch - but that's a possibility. Position A - DCC: Track pickups feed the decoder, decoder output connect to motor leads. Position B - DC: Track pickups feed motor, motor outoputs of decoder are disconnected, track pickups to decoder are disconnected. A 4PDT switch would work. Doesn't even have to be center off - if you only flip it while the loco is off the track. No lights in DC mode, but it would be easily switched between plain DC and full DCC operation. A jumper would work, too - 8 pin DIP plug, with pins shorted across. Two sockets - in one, the plug links track pickups to the motor, but the decoder inputs and outputs are not connected, in the other, 2 of the pins are track power to decoder, the other 2 are decoder out to motor. Sort of like early Atlas DCC locos, before the decoders could do dual mode. They had a similar jumper, it didn't replace the decoder, the jumper simply decided if the decoder was in the circuit or not.

                          --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by BigDaddy on Sunday, January 17, 2021 2:18 PM

I looked up an old thread and posted in that instead of this one.

There are constant lighting circuits.

Randy then commented "That simple circuit with the LED and the CL25N3 driver is directional as is. The LED will only light when the polarity is correct, so on one end of the loco, the LED conencts to the right rail and the driver connects to the left rail, for the other end of the loco, flip those connections. If they are backwards (rear light goes on when loco moves forward), just reverse both circuits."

                               --Randy

Henry

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Posted by mbinsewi on Sunday, January 17, 2021 2:21 PM

As far as the lights go, it would be like before decoders, I used to install LED's in my Athearn BB locos.

If he took his loco to someone with a DCC controler, and function buttons, could he set F8, and would the sound stay off when He takes it back to his layout?

Or would it go back to default as soon as he powered it on.?

Probably a dumb question, but...

Mike.

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Posted by rrebell on Sunday, January 17, 2021 5:11 PM

Best advise would be trade it for a DC engine. Though I think the one he has is a very good value for the price (asuming he didn't pay MRRP), there are much better engines he could get that will run even better.

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Posted by Overmod on Sunday, January 17, 2021 5:13 PM

mbinsewi
Probably a dumb question, but...

Far from a dumb question.  As noted the 'Sound Value' engines default to sound-on when in DC, and that is the objectionable thing here.  It's reported that in DCC they always power up with sound on and while you can then 'mute' them using CV8, you have to do it on every 'power-up', which is an objectionable thing there.  

What I wondered, on and off, is whether one of the 'Quantum Engineer' style boxes to access features on some locomotives, could give him the ability to send the CV8 code to mute the sound with a simple button push every time the locomotive starts making noise...

... of course, the switch in one wire to the speaker is quick and far more definitive in solving his issue.

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Posted by rrebell on Sunday, January 17, 2021 5:23 PM

To mute on Digitrax you just hit a button.

 

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Posted by ATLANTIC CENTRAL on Sunday, January 17, 2021 5:25 PM

rrebell

Best advise would be trade it for a DC engine. Though I think the one he has is a very good value for the price (asuming he didn't pay MRRP), there are much better engines he could get that will run even better.

 

What does this mean? I don't have one, but I have seen these locos run, they run very nice.

What would be better if he wants a USRA light Mikado? And I assume in Maine Central? 

He wants DC without sound, so Broadway is not a better choice?

Please explain?

Sheldon 

    

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Posted by ATLANTIC CENTRAL on Sunday, January 17, 2021 5:26 PM

rrebell

To mute on Digitrax you just hit a button.

 

 

He does not have DCC.......

Sheldon

    

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Posted by mbinsewi on Sunday, January 17, 2021 8:23 PM

Well, I hate to drag this on. following Randy's common sense reminder as to how DC locos were wired, (my reference is Athearn BB locos) , and have working directional lights, maybe, if I were the OP, I'd consider disconecting the speaker, and leaving the DM decoder in place, which would seem to be the easiest route for the lighting.

I have no idea how any of this would affect the plug-ins, between loco and tender.

Like I said, my experience with any of this is older Athearn BB locos, that did not have the board.

Mike.

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Posted by ATLANTIC CENTRAL on Sunday, January 17, 2021 8:47 PM

mbinsewi

Well, I hate to drag this on. following Randy's common sense reminder as to how DC locos were wired, (my reference is Athearn BB locos) , and have working directional lights, maybe, if I were the OP, I'd consider disconecting the speaker, and leaving the DM decoder in place, which would seem to be the easiest route for the lighting.

I have no idea how any of this would affect the plug-ins, between loco and tender.

Like I said, my experience with any of this is older Athearn BB locos, that did not have the board.

Mike.

 

Easiest? Yes. Best? No.

DCC locos, especially with sound, operated with DC run badly. You turn the throttle up half way before they move, then your speed control is "touchy".

Since the OP does not want sound, his loco will run much better with the decoder removed.

At this point we have no idea of his skills, or his access to someone with the necessary skills and knowledge.

But it's not that hard.

Sheldon 

 

    

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Posted by mbinsewi on Sunday, January 17, 2021 8:54 PM

ATLANTIC CENTRAL
But it's not that hard.

And I agree, just thinking out loud on the OP's options.

Mike.

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Posted by MECman on Sunday, January 17, 2021 10:02 PM

Sorry to be absent from my own thread. My query was moved from general discussion and I didn't realize it. Thought it was deleted. I believe Sheldon has explained why removing the decoder completely is my best option for straight DC without sound. My Bachmann 2-8-0 without dcc has much better low speed performance than the sound value 2-8-2. I'm a complete ignoramus when it comes to electronics, so perhaps I should bring this to my lhs repair  guy. It is a nice looking model with MEC paint which is hard to find. I'm sure I could figure it out with step by step directions but hard to come by since most folks are delighted with dcc and sound. 

David

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Posted by ATLANTIC CENTRAL on Sunday, January 17, 2021 10:17 PM

MECman

Sorry to be absent from my own thread. My query was moved from general discussion and I didn't realize it. Thought it was deleted. I believe Sheldon has explained why removing the decoder completely is my best option for straight DC without sound. My Bachmann 2-8-0 without dcc has much better low speed performance than the sound value 2-8-2. I'm a complete ignoramus when it comes to electronics, so perhaps I should bring this to my lhs repair  guy. It is a nice looking model with MEC paint which is hard to find. I'm sure I could figure it out with step by step directions but hard to come by since most folks are delighted with dcc and sound. 

David

 

If you have a good repair guy, he will have no problem removing the decoder and rewiring for DC, and making the lights work.

You will be very happy with the performance on DC once the dcoder is gone.

Sheldon 

    

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Posted by rrebell on Monday, January 18, 2021 11:07 AM

ATLANTIC CENTRAL

 

 
rrebell

To mute on Digitrax you just hit a button.

 

 

 

 

He does not have DCC.......

Sheldon

 

No answer to question from another person here, quote was not working again, hope it dose now.

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Posted by wjstix on Tuesday, January 19, 2021 9:03 AM

My suggestion would be to contact Bachmann's parts / service department and inquire of buying a "DCC ready" tender for your engine. Bachmann has a pretty good supply of parts, and they aren't all that expensive. You just unplug the harness from the tender to the engine, and plug in your new DC tender. If they don't have a Maine Central tender, you can just get any tender that's correct for that engine (any other railroad, or undec) and swap the tender bodies.

You could then sell the sound decoder equipped tender, probably for twice what you paid for the DCC-ready tender. I believe the 2-8-2 uses the same USRA tender as several other Bachmann engines, so I'd bet a lot of folks would be interested in buying the sound tender.

https://www.bachmanntrains.com/home-usa/index.php

 

Stix

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