Athearn locos have several built-in hindrances to smooth and easy running.

Believe it or not, the motor is NOT one of those hindrances. The Athearn motor takes to Pulse Width Modulation control so well that if you remove the motor from the loco and hold it in your hand while controlling it with a decoder, you'll see that it operates very precisely, almost like a stepper motor. However, the magnets in the motor are not secure. If the decoder you use is not a "Quiet Drive" type decoder, you may want to take the motor apart and put a drop of silicon based glue, such as Goo, on each magnet to hold it in place. Otherwise, they may vibrate with the pulsing and make noise.

If the motor isn't part of the problem, what are the hindrances? More importantly, how can they be fixed? Following are a list of these things. We'll tackle them one at a time - in relation to operation with a DCC decoder.

Power then travels from the bearings to the side frames. These bearings need to be able to slide up and down in the slots for them in the frame, so they can't be secured firmly. There are two ways to handle this: again with Conducta Lube or by soldering power pickup wires directly to the bearings. These bearings are not very large, so soldering a wire to them is fine work. If your soldering skills are not tops, I wouldn't try this unless you have sufficient extra bearings for replacement if you make a mistake. For wire, I suggest you use the soft decoder wire that comes on Digitrax's Z- and N-scale decoders.

One advantage of soldering power pickup wires to each wheel bearing is that it eliminates the next problem - the bolster.

Power comes from the left rail, through the side frame, then through the bolster to the chassis. The problem is, the truck frame bolster surface is stamped steel and the chassis surface is pot metal. Now I'm no metallurgist, so I can't tell you why what happens happens. All I can tell you is some of the experiences we've had.

The first experience was with a loco a customer sent for decoder installation. For some reason, it just wouldn't run. The motor worked when connecting power directly to it, but not when it was sitting on the rail. So I got a meter and started probing to see where power was stopping. It was stopping at the bolsters.

My first try at a solution was to remove the trucks, clean the bolsters, and lubricate with Conducta Lube. It still didn't work. I filed and polished the bolster surfaces, lubricated again, and it still didn't work. Having learned a little about problems with dissimilar metals when working for Southern California Edison in a past life, I started scrutinizing the situation. Out of frustration, I made a couple of shims out of some thin brass stock I had. With these shims placed between the truck and chassis, power would flow - from the stamped metal to the brass shim, from the brass shim to the pot metal chassis. For some reason, something happened over the years to keep electricity from passing from the stamped steel to the pot metal, but would flow from stamped steel to brass and from brass to the pot metal.

My next encounter with this was with Steve Staples (our current decoder installer). He called concerning an Athearn that wouldn't run. Well, I had experience with this. I quickly told him what I suspected, but then advised him to solder the black decoder wire directly to both left side frames - eliminating the electrical problems of the bolsters. If you have soldered your power pickup wires directly to all of the wheel bearings, as previously suggested, this potential problem has already been eliminated. But if you soldering skills prevent you from soldering to the bearings, you can solder the wires to the side frames as suggested to Steve at that time.

Any one-amp decoder will work with most Athearn locos made after about 1980. Prior to that I'd suggest a decoder that puts out more than 1.25 continuous amps. However, there are certain decoder features that can make Athearn locos run better than they will without them. These features are: V-Start, Kick Start, High Frequency pulses, and Dither. Train Control Systems makes the only decoders I know of that have all of these features for the resident speed table. We'll discuss each of these features below. If your decoder doesn't have one or more of these features, you'll have to do a little work on the drive train for more improvement. Of course, you can do the extra drive train work even if you do use a Train Control Systems Decoder, it's just that you're not going to see as much improvement for the amount of work you'll have to do - because the decoder may have already compensated for those deficiencies.

First, all Train Control Systems decoders are supersonic - what Train Control Systems calls Quiet Drive. If your decoder doesn't have a supersonic PWM feature, the decoder's pulses can set up a resonance in the shell causing an audible buzz. Not all locos or decoders will resonate like this. But if yours does, the solution is to tape thin lead to the inside of the shell. Lead won't vibrate, so it can't resonate with the decoder pulsing. Something else that helps is to lubricate the commutator with a very tiny drop of Conducta Lube each time you service the loco.

Next is Dither. Dither is a feature that was initially developed to counter the torque loss caused by supersonic pulsing for Quiet Drive. What it does is introduce a certain amount of additional power at a different frequency. This is the main feature that overcomes the "stiction" of the motor's magnets and drive train's imperfections.

Dither is programmed with CVs 56 and 57. Factory default for these two CVs is zero (0), which turns Dither off.

CV56 is used to select a frequency. The range for this CV is 0-255, with 0 (zero) being off. The highest frequency addition of 30 extra pulses per second is obtained with a value of 1. The higher the value, the fewer additional pulses are added. A value of 5 is the recommended starting point, but the optimum value is obtained through experimentation. The practical range is 1 through 10.

CV57 controls the amplitude of the additional pulses. The range for this CV is 0-255, with 0 being off and 255 being the highest voltage pulse. The practical range is about 5 through 50. The recommended starting value for this CV is 25 to 30. The optimum setting is again obtained through experimentation.

Dither's extra voltage bumps are provided only in the lower 1/5 of the speed range, where it's needed. However, it can be used in conjunction with V-Start and/or Kick Start to provide whatever is needed to make most any loco start and run smoothly at any speed. Yes, Train Control Systems makes Kick Start available for use with the built-in speed table.

V-Start is used to program the decoder to provide enough voltage at speed step one to make the loco run at whatever slow crawling speed you want. By programing the loco to start and run on speed step one, you get the full speed range of Dither possible. If the loco doesn't start till speed step #7, for example, that's seven speed steps that Dither won't be providing you with any advantage.

Even with Dither, some locos may not start at the slow crawling speed you desire. You may have to give it a little extra throttle to get it started, then back off to speed step 1. Kick Start is designed to fix that. Train Control Systems decoders not only have Kick Start implemented for use with the built-in speed table, but it is also programmable in two different ways: how much kick and for how long. I don't know of any other decoder that has Kick Start Duration programming.

CV65 is used to program how much Kick to provide. If your loco has to be run up to a speed step higher than #1 to get it started, but will continue to crawl when backed off to speed step 1, CV65 needs a higher value. If your loco leaps to a start, then settles down to a crawl, CV65 needs a lower value.

CV 58 is used to program how long the extra Kick is to be provided. If your loco jerks, but doesn't start on speed step 1, chances are CV 58 needs a higher value. If your loco starts, then increases speed a little before settling down to a crawl, chances are CV 58 needs a lower value.

The drive shafts can sometimes (usually) have flash left over from manufacturing. Further, they can wobble. There are a couple of ways to take care of the flash: take it apart and trim and polish all flash points or get some Pearl Drops tooth paste (or other polishing compound) and wear them in - force polishing compound into joints and run for a few hours. This is usually best done by blocking the loco up off of it's wheels and connecting power directly to the motor. After wearing the parts in, you'll still have to take it apart to clean all the polishing compound off.

If your drive shafts wobble, that can be fixed with some very tiny rubber bands, such as those used on teeth braces. Putting them around the joint will hold them centered. I've known some people who used aquarium air hose to make connections between a shaft and it's connection, instead of the standard U joint.

The gears in the Athearn truck can also have flash left over from manufacturing. The solution for this is the same: trim and polish or Pearl Drops tooth paste.

With all of those things taken care of, your Athearn loco should run almost as well, if not as well, as any other high-quality loco.