# Athearn BB Conversion Help



## ma454mike (Aug 30, 2014)

Hi all, New to the Forum myself. I have returned to the Hobby after 15 years. I am in the process of converting my modest fleet of old Athearn BB locomotives to DCC. I read quite a bit here, Watched you tube and bought some decoders. The first attempt im sure I fried the DH126 digitrax decoder. plus took over an hour. I never could get that one to program. The second on one went a bit faster with the hard-wiring. I double checked everything before setting the loco on the programming track. Everything works great except no light at all. Anyone have suggestions? I even took the bulb out and checked it with loose wires. 

I'm still waiting for replacement decoders from digitrax.

I have also had success reprogramming a Bachmann gp-40 that I bought with on board decoder.

So far I am enjoying this new world of DCC and am planning a new layout.


----------



## ggnlars (Aug 6, 2013)

First things first, 
Can your decoders handle the stall current? In that question, I'm really asking which motor your BB loco's have. The round motor typically has a high power stall current greater than 3. The newer rectangular motors with brass fly wheels will have a stall current at 2 or lower. 
You need to be sure your decoder can handle that much current. Anytime you start the motor it draws the stall current corresponding to the voltage level being applied to the motor. Thus is usually momentary and does not cause a problem. However, dirty track and wheels can prolong the exposure and lead to decoder failures. 
Obviously, you need a decoder with sufficient capabilities to handle the current load.
Any engine with a decoder runs better than without it. This can only be demonstrated in a fully DC system, but the motor is still DC in a DCC system. The performance improvement is fundamentally the same. 
I believe at the decoder is intended to control an LED. Depending on the decoder, I do think you may be able to control a light bulb, but I think you have to change the light connection location. My only experience is with LEDs. They work great with the proper resister in the circuit. 
I also find that you need to limit the heat the decoder sees when soldering the connections. Solder intended for electronics, deliberate crisp solder actions and a solder machine where the temperature can be controlled are important for successful decoder installations. 
Good luck,
Larry
Check out my blog: www.llxlocomotives.com


----------

