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How can I convert Athearn BB locomotive to DCC

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  • Member since
    April, 2019
  • 21 posts
How can I convert Athearn BB locomotive to DCC
Posted by Orangeman on Saturday, May 25, 2019 8:22 PM

Yes, I did watch a video on YouTube which seemed fairly simple, but the harness the "instructor" used is no longer available. I did Google the harness and waded through lots of info and ended up totally confused. Can anyone suggest a harness that is currently available to make the conversion. Any tips on how to make a painless conversion would be appreciated also. 

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Posted by IDRick on Saturday, May 25, 2019 8:45 PM

A nice, easy to understand, video from Digitrax:

https://www.youtube.com/watch?v=wH5rjFdZFOM

The process is the same with a different decoder.  Buy a 9 pin JST harness, example is Digitrax #245-DHWH and your decoder of choice.  The decoder plugs into the harness and you attach the individual wires from the harness to the locomotive as shown in the video.

Others will have their own preferred approaches.

  • Member since
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  • From: Southern Florida Gulf Coast
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Posted by SeeYou190 on Saturday, May 25, 2019 9:12 PM

There are two tricky parts for Athearn Blue Box decoder installations.

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1) Isolating the motor from the frame.

2) Getting frame (ground) connection to the decoder input.

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It is probably best to try your first installation following the videos. Later develop a technique that suits you best.

.

There are many ways to skin this cat.

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-Kevin

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Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by mbinsewi on Saturday, May 25, 2019 10:09 PM

I just watched IDRick's link, and it is a nice, slow, how-to, on hardwireing a decoder. Whats changed is the decoder, it's now the DH126D.  It's all the same, just a newer decoder.

I also agree witth Kevin, there are other ways.  Wires can be connected right to the trucks, the black wire can be connected in a couple of different ways, as that head light connection to the frame, is not always the greatest.

You'll figure all that out, as you become more experienced with hardwire installations.

Digitrax used to make a "plug-n-play" type decoder harness, for Atherans, but that is no longer offered, so the "hardwire" is the best option.

FIRST, I would check the amps, with a multimeter, and make sure the Athearn motor on your loco, draws at, or better yet, under 1 amp., under a load.  The decoder is set at 1.5 amps.

The "gray" colored motors are not so good, most of the "gold" colored motors are usually OK.

I think Athearn blue box locos are the easiest to work on, and convert to DCC.  

Mike.

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    April, 2019
  • 21 posts
Posted by Orangeman on Saturday, May 25, 2019 11:42 PM

mbinsewi

I just watched IDRick's link, and it is a nice, slow, how-to, on hardwireing a decoder. Whats changed is the decoder, it's now the DH126D.  It's all the same, just a newer decoder.

I also agree witth Kevin, there are other ways.  Wires can be connected right to the trucks, the black wire can be connected in a couple of different ways, as that head light connection to the frame, is not always the greatest.

You'll figure all that out, as you become more experienced with hardwire installations.

Digitrax used to make a "plug-n-play" type decoder harness, for Atherans, but that is no longer offered, so the "hardwire" is the best option.

FIRST, I would check the amps, with a multimeter, and make sure the Athearn motor on your loco, draws at, or better yet, under 1 amp., under a load.  The decoder is set at 1.5 amps.

The "gray" colored motors are not so good, most of the "gold" colored motors are usually OK.

I think Athearn blue box locos are the easiest to work on, and convert to DCC.  

Mike.

 

Mike, that is the exact video I watched. I was wading through all the info without a clear cut "get this decoder for Athearn BB". Thanks for being specific.

Thanks to everyone for pointing me in the right direction. Hopefully from here on installing it will be the difficult part, which I don't mind as much as not knowing where to start. Thanks all!

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Posted by mbinsewi on Sunday, May 26, 2019 8:13 AM

Orangeman
I was wading through all the info without a clear cut "get this decoder for Athearn BB". Thanks for being specific.

The Digitrax web site has a nice easy to use drop-down type decoder selection feature.  

Check it out.  It gives you all the options and decoders that fit any loco of any scale.

http://www.digitrax.com/

The TCS web site also has a great "Installations" section, where it shows step by step installs for a long list of locos.

https://tcsdcc.com/installations

The amp test I told you about is the "stall test" where you measure the amps while restraining the loco from moving.

Good luck!

Mike.

  • Member since
    July, 2007
  • From: New Lenox Il.
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Posted by LenS on Sunday, May 26, 2019 9:58 AM

mbinsewi

 

 
The amp test I told you about is the "stall test" where you measure the amps while restraining the loco from moving.

Good luck!

Mike.

 

I've done about 40 or 45 Blue Box locos and one thing I found out is that if the loco didn't run well or quiet using DC, it most certainly won't run better with DCC. The old grease and oil gunk doesn't help nor does the noisy gears.

There are many great videos available on UTube. Some that come to mind are from tommy022481 and TSG Multimedia. Another good reference is mcor-nmra.org/Publications/Articles/Athearn_TuneUp.php

 

Good luck and have fun!

 

Len S

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  • From: Richmond, VA
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Posted by carl425 on Sunday, May 26, 2019 11:00 AM

LenS
I've done about 40 or 45 Blue Box locos and one thing I found out is that if the loco didn't run well or quiet using DC, it most certainly won't run better with DCC. The old grease and oil gunk doesn't help nor does the noisy gears

That takes me back in time!  I used to break in my BB locos by running them for an hour or so with Pearl Drops on the gears.  When I saw how effective it was at polishing the gears and quieting the gear noise I vowed to never use it on my teeth.  As a side benefit it gave the loco a nice minty smell. Smile

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by BigDaddy on Sunday, May 26, 2019 11:18 AM

There are some people in the forum who swap decoders to other engines, but for most of us, a decoder installation in permanent.   Since soldering is requried, a connector doesn't give us anything we need.

Digitrax used to make a DHAT harness that replaced the motor clips and no soldering was required.  It hasn's been available since 2012

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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    May, 2010
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Posted by mbinsewi on Sunday, May 26, 2019 3:36 PM

I like this tutorial, if you will, on "tuning up" Athearns, even if your not converting it to DCC.

http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.php

Mike.

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Posted by wjstix on Sunday, May 26, 2019 10:06 PM

Orangeman
 Mike, that is the exact video I watched. I was wading through all the info without a clear cut "get this decoder for Athearn BB". Thanks for being specific.

Keep in mind no one makes a decoder "specific" to Athearn BB engines. There are dozens and dozens of decoders that work with Athearn or any other engine. As noted, someone used to make a harness for BB installations, but the only real difference is it had slide-on connectors for picking up power from the 'tabs' sticking up from the trucks so you didn't have to solder the wires. 

One thing that can be confusing is even if it looks like a decoder has wires coming out of it, the wires are actually coming out of a harness that is plugged into the decoder. Some decoders protective outer coating cover the connection, but it's still there. So when doing a "hardwire" installation (that is, installing a decoder when there isn't an 8-, 9-, or 21-pin plug) what you're doing is wiring the wires coming out of the harness to the motor, lights etc. The harness has nine holes that allow you to plug it into a 9-pin decoder - which is probably the most common type. So you can install a non-sound decoder now if you want, and later unplug it and plug in a sound decoder - as long as the sound decoder has the normal 9-pin connection.

Stix
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Posted by jjdamnit on Sunday, June 02, 2019 4:31 PM

Hello All,

Orangeman
Any tips on how to make a painless conversion would be appreciated also.

Albert Einstein has been credited with saying, "Once you open a can of worms the only way to get all the worms back in is to use a bigger can."

As has been mentioned there are no Athern Blue Box specific decoders (unless you consider a higher amperage decoder for older, higher draw motors).

The BBs use the chassis as an electrical conduit for one side of the motor (bottom). A clip or small strip of metal holds the motor brush and it's spring.

Two prongs on this bottom clip electrically connect the bottom of the motor to the chassis.

The other side of the motor (top) uses a strip of metal between the gear towers and the motor.

Again, this strip also holds the motor brush and spring on the top of the motor.

On the gear towers there are two large contacts.

As noted, the one on the top of the gear towers conducts electricity through the top strip to the motor. 

A second set of contact are just above the truck side frames and conduct electricity from the wheels on that side through the frame to the bottom of the motor via two small prongs on the bottom brush retaining clip.

The most important aspect of any DCC installation is to completely isolate the motor from it's original electrical pathways.

The original motor mounts should also be replaced with plastic isolating ones.

After removing and replacing the motor mounts I carefully remove the motor brush retaining clips both top and bottom- -don't loose the small springs or motor brushes.

I then cut the top clip so it is the same size as the bottom one.

With a small screwdriver I flatten the two small prongs on the bottom clip.

With the clips off I solder the new wires; Gray and Orange, to each one.

Replace the motor brushes and springs and secure them with their respective clips and new wires.

As an extra measure of security I swap the bottom; with the flatten prongs, for the top one so there is no chance of the prongs contacting the frame.

If the polarity of the motor is reversed it is a simple matter of swapping the top clip for the bottom one. 

For the gear towers I take a heavy pair of side (wire) cutters and remove the tabs on the top of the gear towers and the sideframes.

You may need to file the edges of the lower sideframe contacts to completely isolate the trucks from the frame to avoid catastrophic electrical occurrences.

Then I solder the respective wires to their respective positions using Black wire for the side frame contacts and Red for the top contacts.

This completely isolates the trucks from the frame.

Now you are ready to reassemble the motor and gear towers in the frame.

Once assembled you now have an NMRA (National Model Railroaders Association) compliant frame with an isolated motor and trucks.

From here follow the wiring schematics of your chosen decoder.

Many folks skip isolating the truck side frames, opting to use the chassis for the lower motor contact.

With any DCC installation; from decoders to track, a solid electrical path is essential for reliable operation.

At this point I also upgrade the incandescent bulbs to LEDs, but that's another post.

Good luck, and as always...

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

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