Last night I decided that it was time to put a decoder in the new AC4400. It runs so quiet on DC that it should just whisper on DCC right? WRONG!! I installed the decoder, placed it on the track and gave it power. I’ve heard electric can openers that are quieter. I worked on it for a couple of hours to see if I could get it to run quiet, but to no avail. At about 10:00 pm I removed the decoder and rewired the unit for regular DC. I was thinking that maybe it’s the decoder that’s causing the noise, so I installed it in my Proto 2000 PA1. Expecting to hear a high speed can opener I applied the power and to my surprise the PA eased forward and trundled down the main line with nary a sound. Seems to me that the quiet motors of the RTR Athearn units aren’t all they’re cracked up to be. I know I won’t be buying another one real soon. It’s funny. I put a decoder in a cheap BB and it runs without a sound. I put one in an expensive RTR and the neighbors can hear it. Go figure.
Jeff,
One of these days I will create a petition for Athearn to replace their outdated flawed motor for one that is suitable for DCC, with or without sound. [soapbox] In addition a Mashima, Kato or one their clones type motor,will draw 1/10 of the current of the Athearn RTR motor. I recently replaced three motors in RTR RS-3 with Helix Humpers (because of the space limitations). I prefer A-Line supplied Mashima motors or NWSL types. Perhaps with a new president, Athearn will consider such a petition. Many contributors to this and other forums have expressed the same opinion. If Atlas can find suitable motors for their Trainman line and Walthers can use low current quiet motors in their Proto 1000 line, Athearn can as well. There are several Athearn RTR locos I would love to have; realizing I have to change the motors which adds to the cost, has stalled my pursuit of them.
That doesn’t make a lot of sense. I wonder if a different brand of decoder would do the same thing? Is it motor noise or RF noise? I opened up an IHC that I have and was surprised to see 3 ceramic capacitors run between the two motor leads. Someone said it was to cut down on motor noise. Don’t know if you can do somthing like that with DCC or not.
I know some of my locos make a loud buzz through my stereo when I run them. My Bach DCC was the worst offender.
What decoder? Some have good BEMF and PWM, but if you used a 100 LC from Soundtraxx, you will likely have a noisy drive. Even then, there must be other decoders that have the same characteristics. Perhaps this is one…or it is defective.
The motor is responding to pulse widths transmitted by the decoder, so if it is noisier now that when on DC, it must be the decoder.
I agree with selector, if it is not there on DC it is the decoder. I have DCC a bunch of Athearn RTR and have never had one make more noise on DCC. I try to buy a decoder recommended for the unit and not just “a decoder”. I don’t buy Lenz, Bachmann or Atlas decoders just for that reason. Saving money is not always the best idea.
Hi guys, just a couple of cents worth of experience.
I’ve had some cheaper MRCs and some of the Atlas (FM H-16) stock decoders make some terriible noises. Two stock FMs, one ran good and was quiet, the other never ran good or quiet, sounded like a coffee grinder. I’ve been replacing all my decoders with TCS and running capabilities and quietness have been great, installed them in Atlas and Protos. If I go to sound, I’d like to try and piggy-back the TCS decoders, I think they’re that good , but that’s just one man’s opinion and experience. Hope this helps.
Brad
Selector: I use only one type of decoder. The NCE Silent Running 2 function decoder, Walther’s part #524-139. I tried a second decoder in the 4400 this morning and got the exact same result, load humming and growling. This tells me that the decoder is not at fault. I put the one from last night into a P2K PA1 and it runs without a sound. I put the other one into a Bachmann GP40 and no noise issues. The problem is definately with the motor. I’ve bought two expensive Athearns and both have had issues that quality units should not have. I will not be buying a third one. I’ll be sticking with the BB and with P2K.
That’s interesting. I thought RTRs and BBs used the same gold motor that Athearn’s been using for 25 years now. Does the motor in your AC4400 look like a BB gold motor, or does it look more like a Mabuchi can? My RTR F7 from an Athearn train set uses a very cheap Mabuchi can motor.
You’re probably right Jeff, Ive only got one Athearn loco left and I replaced the athearn motor with an atlas motor. Years ago I used to buy a blue box, put on NS wheels replace the wiring and put in a can motor, but I think that they should be able to justify better motors nowadays along with the other advances they’ve made.
Brad.
That would be nice…Their Genesis motor is sweet…Why can they find another sweet motors for the RTR?
I don’t use DCC but,All of my RTR has been smooth and quiet runners from the box.
In that case, I see what you mean, Jeffrey. It could therefore be the motor, but is just as likely to be another part of the assembly to and including the gearbox/drive. Maybe you have a dry bearing, bad brush, flashing or grit someplace?
Sorry to hear that you are not getting the best out of this locomotive.
-Crandell
I do have a question:
If you only use one kind of decoder “The NCE Silent Running 2 function decoder, Walther’s part #524-139” and replace it with the same brand of decoder isn’t it possible that the decoder is not suitable for that locomotive?
I’ve used the same type of decoder on an Athearn BB F7 that has the same type motor as the 4400. The F7 runs quietly, no humming, no growling.
More info about the Athearn RTR motor; it is not the same construction as the older RTR motor; the old motor had a single magnet hull in which the armature was installed. The newer motor has two permanent magnets - one over the armature and one under it; they are friction fit and not anchored to the outer metal frame which is a single band bent around and meshed together at the bottom. This is a source for vibration and noise. Remember folks PWM (Pulse Width Modulation) drives do not guarantee quiet operation with every situation; harmonics are involved here. Occasionally a motor is found to be noisy with PWM control when other motors of the same brand and model do not; any loose or vibrating part of the motor assembly is a potential source for noise.
In some cases you can change the PWM frequency with CV’s and reduce the noise; but that usually works when the motor is normal. I believe Jeffrey’s motor is flawed (more than normal for Athearn RTR [;)]).
BTW, the motors used in most Athearn Genesis locomotives are either Buehler or Roco. Proto 1000 RS2’s use the Roco motor as well; the Buehler motor is similar to the motors used in some early 90s Overland chassis.
Many of you have expressed quiet operation with Athearn RTR units; either you have the 1-5 percent of the motors that are quiet or you have the fortune of using them in an environment that masks the sound the normally make. If you are happy then that is all that matters. However extended testing has shown premature bearing wear and increased noise under heavy use; favorite locos heavily used will require early replacement. Also DCC users: beware that with increased use the motors can begin to draw more current if the bearings start to wear.
I have spent many, many hours tweaking, testing and adjusting Athearn RTR motors. I encounter them installing DCC decoders with and without sound. Replacing them at any time with a good can motor (or Genesis equivalent) gives you the following:</
Another issue to consider is quality control regard the RTR line. I’ve had several recent RTR purchases returned because of problems like trucks not receiving power and circuit board problems that affect DCC decoder conversions. Athearn makes a good product but the RTR line is worth test running before purchase (if possible). This is an example of the importance of a LHS shop where you can test befor purchase. Otherwise you had better pick up some tinkering skills or get friendly with someone local like Cmarchan.
One tip to reduce noise is to slip thin strips of foam in between the body and motor.
Good Luck
Carl,For me its been smooth quiet running on my test track straight from the box…I am a member of 2 HO clubs and I am yet to hear any noise complaints…I highly suspect your 1-5% is way to low seeing Athearn remains the #1 choice locomotive in this area due to local economic reasons and everybody shares their views and complaints of every new model.I can tell you the most complaints comes from another famous brand due to several things…
I been tweaking Athearn motors since the 60s I am yet to change out a motor to quiet one down…There are many ways to tame this mild beast that doesn’t cost extra money.
Maybe everybody I know that buys Athearn RTR has the luck of the Irish? I hear more complaints on the Big Boy then the RTR diesels…[:O]
Brakie,
mechanically, I prefer the OLDER Athearn motor of the wide shell days. I’ve been able to tweak some of those motors with better results than some of the new ones. I realize not all owrners will have a dispositon to the motor’s characteristics. However, I believe Athearn can replace the motor in production without additional cost. Most ready to run Athearn’s are not as cost effective at MSRP as they used to be; you pay the same amount for a Atlas Trainman loco or a Proto 1000; these units run better, draw less current and have fewer issues long term. I also believe the motors QC are getting worse with each passing generation. I would like to preface the following as a friendly debate:
I purchased two Athearn RS-3 and was asked to install sound on a third unit. One of the units was fairly quiet for an Athearn and the other was a growler. I discovered the growling was caused by rough edges on the commutator sections and slop in the forward rear movement of the armature; also there is too much play in the motor brushes; they should not be allowed to move in a angle in the mounting sleeves; they should only move up and down. In addition the magnet pieces were not tight in the body; Athearn tried to tweak the unit by pinching the side
Carl,
I don’t want to get into a flame war either, but I did want to thank you for passing on the information that a lot of us may eventually need. I just bought two of the RS-3’s and installed NCE decoders with no problems and no complaints. I also have a bunch of older Athearns that I would like to keep that do sound like coffee grinders so tips on remotoring are appreciated. I have removed the older MRC decoders from other locomotives because of the huge amounts of noise they made and put them aside for future electric engines (NH EF’s and EP’s). I must admit I still don’t understand why Jeffs’ makes noise with a decoder and not without, but time will tell. [:)]J.R.
Carl,The only thing I am saying is I have the experience to tame loud locomotives…99% of that was quieting down the old KMT drive found in brass diesels of the 60s.Mind you not whisper quiet but,at least 50% quieter then they came… After that I found Athearn locos was a breeze to tame.I will stand by my statement I am yet to change out a motor.
Back to today…I fully agree Athearn needs a better motor for the RTRs however,to date all of mine has been quiet runners and quite smooth…Also NONE of the club members has report any problems that’s why I said your 1-5% is low.I go by what I see and hear at the 2 clubs as I find they are more reliable source since they will report problems loud and long.
Nothing against you Carl but,thats the way I am after all you can read anything good or bad on a forum.Sadly I have read tons of pure BS as I suspect you have as well.Again nothing personal.
Now if you want a “super” Athearn GP38-2/GP40-2 the use the drive from a Atlas GP38 or GP40.Its not hard but,not a job I would recommend to the beginner or faint of heart.