Upgrading older Athearn to DCC - Performance issues

[TimThomas]

Hi All,

I have upgraded a few Athearn loco's from the late 80's with the digitrax DCC decoders and am having many performance issues. (Not with the decoders, they seem to be working fine). The loco's get to the point of starting to roll and then stall out or will get up to speed and then seem to lose power and run erratically. I have cleaned the contacts and wheels very well and have gotten some electrical improvements, but cannot get the slow speed performance I used to get with the DC versions. Any tips or tricks or advice? I've upgraded three of these this way (I can't let them go, they're too cool!) and all have the same issues. The newer DCC locos run extremely well on my layout and I realize the technological upgrades over the past 30 years come into play here, but it seems as though they should still run better than they are right now.

Thanks

Tim

[CNR378]

Increase your 'Kick Start' (CV 65).  Default is 0, try 2 or 3.  This should help with slow speed operation.

Peter

[locoi1sa]

Tim.

 Do you have track pickup at the trucks or the frame on one side? If one side is getting power from the frame then you will have to either wire the trucks or polish the frame and truck pad for better contact. Another thing to look at is the plating of the wheels. If these units are run much then the chrome plating is peeling off the wheels and the pot metal is not a very good conductor. You may have to re-wheel the locos with some good aftermarket wheels.

         Pete

[MisterBeasley]

Do you have power pickup from all of the wheels?  Some of these older engines would only supply power through one side of each truck.  If that's the case, adding some pickups to the unused wheels will greatly help your performance.

I would take an ohm-meter and "buzz out" the connectivity.  Make sure that all wheels on each side form a single circuit.  You may have inadvertently lost a connection while installing the decoder.  Restoring any lost power circuits will do wonders for performance.

[rrinker]

 ALso, did you use the Digitrax harnesses that use the base of the light clip as the pickup point from the chassis? Those pieces are often only loosely rivted to the chassis and are a source of poor contact. A better option is to use thin wire liek decoder wire and solder pickups right to the sideplate of the trucks, a second best alternative is to drill a hole in the frame and tap it for a bras screw, and then solder the wire to the brass screw.

                          --Randy

 

[TimThomas]

All, thank you very much for all the tips! This is great information, I appreciate it. While trying the tips you all sent, I did notice that after I removed the wheels for a good cleaning I inadvertently pushed them too close to the inside pickups (and probably a bit out of gauge) so the friction was too much for the slow operation I needed. I now have an NMRA gauge on the Christmas list and a bunch of other knowledge thanks you guys! 

Thanks again,

Tim 

[MisterBeasley]

When you run the engine and it begins stalling and losing power, what happens to the headlight?

If it's flickering or dimming down, then you have problems getting power to the engine through the wheels.  If the headlight remains steady while the engine sputters, then the problem is with the motor or possibly the gears.

[jamnest]

I have "hardwired" a lot of older Atheran BB locomotives with a Digitrax DH123 decoder.  I do not use the Digitrax Athearn wiring harnes.

I solder the orange and gray decoder leds directly to the copper motor clips.  (Be sure insulate the bottom clip from the frame.)

I solder the red decoder led to both the front and back truck electrical pick up.

I use a tap and drill a hole in the frame and tap a 2-56 brass screw and solder the decoder black leed to the screw.

I remove the Athern light clip and solder 14v bulbs to the yellow/white/blue dedoder leds.

Great performance.  If your locomotive runs great in DC it should do just fine in DCC.