Trouble with DCC

[selector]

QUOTE: Originally posted by SMassey

QUOTE: Originally posted by rayw46

Good Morning Dave,

LOL I just read that and now I have memories of a sadistic homocidal computer giving me nightmares as a child. Great movie tho. I wonder when our DCC systems will be like HAL?

What do you mean by "when", Dave?

[SMassey]

QUOTE: Originally posted by rayw46

Good Morning Dave,

LOL I just read that and now I have memories of a sadistic homocidal computer giving me nightmares as a child. Great movie tho. I wonder when our DCC systems will be like HAL?

[rayw46]

Well, I heard from Atlas. They suggested that I reprogram CV50 to value 8, unless the decoder is the older Atlas model 340/341, which cannot be reprogrammed to run in the quiet mode. Mine, however, is the newer Atlas 342 decoder. I took it to my local hobby shop, where it still ran quiet, and they kindly reprogrammed the decoder for me.
When I tried it at home with the Bachmann system it had quieted down a tad, but it still has a very audible buzz. I guess some decoders are just not going to be compatible with the Bachmann System. I can chalk this one up to experience.

[SMassey]

With the NMRA standards they only have a requiremant for the actual data packets not for the actual frequency of the AC current running through the rails. This sound could simply be a lower frequency produced by the Bachmann system. I use Digitrax DB150 booster for my DCC system and the AC frequency of that system is 60hz just like your wall current. I dont hear any noise from a DCC loco but when I put an analog loco on the rails I hear a buzzing. That buzzing is the result of the track frequecy being chopped in half (30hz) by a DC motor that is trying to run in 2 directions at once. If Bachmann uses a lower frequency for their DCC you may just be hearing the pause between the DC pulses going to the motor like you do when you put a DC loco on a DCC track. I cant say for sure I have not had the opportunity to play with the Bachmann EZ Command system yet. Just an idea tho if the freq is the cause then there is nothing wrong it is just the way it was designed.

[Stevert]

QUOTE: Originally posted by rayw46

I have tried to contact Atlas, but it takes a while. The locomotive is an Atlas Master Locomotive Series model that I purchased about 2 years ago. Although I haven't been able to try some to the things suggested, you guys have been a lot of help. I do appreciate it.

Ray

Ray,
Take it back to your LHS or someone who has a DCC system capable of CV readback, and have them read CV7 .

If the CV7 value is 45, it's a 2-function Dual Mode. If the value is 46, it's one of the 4-function decoders.

I'd be willing to bet that it's a 2-function Dual Mode because those are just noisy decoders. If that's what you have, do yourself a favor and replace it with a Digitrax DH163A0 or a TCS A4X .

If you have one of the 4-function decoders, you can use CV50 to turn on Slient Drive, if it isn't on already. I don't have a manual handy and don't recall either the value or the default (SD on or off). If you turn Silent Drive on and it's still noisy, replace it as mentioned above.

BTW, I guess this is where I should put in a plug for DCC systems, even starter systems, that allow CV readback and have provision for a computer interface. Identifying the decoder family and changing the CV's, even if you don't have the manual handy, is a piece of cake with the free JMRI software.

HTH,
Stevert

Edit: Fixed typo.

[rayw46]

Good Morning Dave,

Sorry, I couldn't resist that. Bachmann's answer was to ship another system to me. There's no telling when I'll hear from Atlas.

Ray

[tstage]

Mike,

Try this link: http://www.trains.com/community/forum/topic.asp?TOPIC_ID=49375

This is a new thread that was started a couple of weeks ago by Joe Fugate, where forum members write their experiences doing particular tasks using the various of DCC systems available. So far, we've discussed the ease of use of the throttles and giving a grade of A+, A, A-, etc. to each system. It's definitely worth a read.

Tom

[Anonymous]

I've been out of railroading for a while. Now DCC is the dream way to control the pike. The question is, which one to use? My railraod will have 5 or less operators, 25 or less engines (over the next 50 years) and will cover 25 x 35 feet. I like continuous running but will have a number of industries to switch for. Digitrex seems to be too much for what I wi***o use. I would really apprieciate some suggestions and what others use and why? Please give me your thoughts!

Mike Garske
[e-mail]

[davekelly]

Ray,

You'd be surprised with the number of DCC gurus on this site!!! I'm pretty confident that one can get a quicker answer to almost any quesion than one would get from the actual manufacturer!

Dave

[tstage]

Ray,

Here's a handy link for comparing decoders from Tony's Train Exchange:

http://www.tonystrains.com/productcompare/decoder_comparison.htm

It would be great to know which kind of decoder Atlas uses in their Master series Geeps. That way you'll be able to determine whether it is a silent or non-silent decoder.

Tom

[rayw46]

I have tried to contact Atlas, but it takes a while. The locomotive is an Atlas Master Locomotive Series model that I purchased about 2 years ago. Although I haven't been able to try some to the things suggested, you guys have been a lot of help. I do appreciate it.

Ray

[tstage]

Stan is correct. From what you are describing Ray, the locomotive is working as it should. Is this Atlas GP-40 one of the "budget" line locomoitves. Also, the dual mode decoder in the locomoitve may be a "non-silent" running decoder. Silent decoders are quiet. Non-silent decoders will "growl" slightly. That's a question you can ask Atlas to verify which kind they use.

Tom

[stanames]

QUOTE:
Guys, I'm getting a little confused with all the DCC Speak and you haven't even really gotten into it yet. Anyway, here is what I can tell you. With the jumper in the DCC Mode, I can not program the decoder to address 10. I think a separate analog controller is needed to do that.

Sorry for the confusion.
What you report is correct and proper operation. If you do not have a separate analog controller then the Bachmann system only supports DCC addresses 1-9. Button 10 is used to control a non decoder equipped locomotive. If you plug in an analog controller then the separate analog controller controls the non decoder controlled locomotive and Button 10 is now DCC address 10.

To operate a DCC locomotive with your system set the address to one of the buttons from 1 to 9. If you hear a small hum when in moving that can be removed by programming the decoder to run at a high frequency.

QUOTE:
When I move the jumper in the loco back to analog operation, as soon as I plug the system into the wall outlet there is, not a buzz, but a squeal. In the analog mode the loco will only run at address 10, which if I have read the instructions correctly, is what it is supposed to do.

What you report is exactly the way it should work.

When you place a locomotive without a decoder on the track (or for your Atlas locomotives you insert the plug in analog mode) the locomotive will squeal. The tone will change as you speed up the locomotive.

The squeal is the motor trying to operate forward and reverse at 9600 times a second. This will occur whenever you place a non decoder locomotive on any system.

From what you report all is operating as it should.

Stan

[rayw46]

Guys, I'm getting a little confused with all the DCC Speak and you haven't even really gotten into it yet. Anyway, here is what I can tell you. With the jumper in the DCC Mode, I can not program the decoder to address 10. I think a separate analog controller is needed to do that. There is even a plug-in on the controller for that. When I move the jumper in the loco back to analog operation, as soon as I plug the system into the wall outlet there is, not a buzz, but a squeal. In the analog mode the loco will only run at address 10, which if I have read the instructions correctly, is what it is supposed to do.

It may be a few days before I can get to my LHS to see if they can reprogram the CV 50 value, but thanks for all your suggestions so far.

[stanames]

QUOTE:
If that is so then why does it run ok on the Digitrax, the programming is the same, the DCC signal must be the same NMRA and all that[]. If it runs ok on the Digitrax and not the Bachmann, then my brain []tells me it's the controller.

Perhaps yes perhaps no. The problem could be a different problem then changing the decoder to its high frequency mode so lets wait before jumping to a conclusion. We really do not have all the information necessary in an email forum since we do not have the problem in front of us to see first hand exactly what is happening. If I had the system and locomotive in front of me I could tell you the answer instantly but such is not the case.

But let me explain why the sounds will be different on different systems.

Its like jumping rope. If you fumble the rope just limps but if you swing the rope just right it forms big loops with no problems.

When you change the DCC track voltage the frequency (noise) of the decoder coupled with the sound chamber (the locomotive shell) will change. For years some users have had more noise with some locomotives on some systems then others.

One difference between the Bachman and Digitrax systems is track voltage. They are different. If you set the track voltage to be identical between the two systems I suspect the result will be the same.

Atlas ships their decoders in low frequency mode. Most of their HO decoders also have a high frequency mode. In high frequency mode the drive to the motor is like pure DC and the noise disappears.

If the noise is present in high frequency mode then the problem is something different.

Stan

[NZRMac]

QUOTE: Originally posted by stanames

Neither your locomotive or system is faulty. Strangly enough this is how it should work but there is a simple fix.

The Atlas locomotive decoder has two modes. In one mode the locomotive is silent, in the other mode the decoder uses a pulsed power that can get noiser as you increase the DCC track voltage. Some people can hear it and for othere is is masked.

The solution is to program CV 50 to a value of 8. You will have to take the locomotive to a dealer or friend why can program these high CVs as the current backmann system can not. Once set for silent mode the problem you have will go away.

Stan Ames

If that is so then why does it run ok on the Digitrax, the programming is the same, the DCC signal must be the same NMRA and all that[:)]. If it runs ok on the Digitrax and not the Bachmann, then my brain [%-)]tells me it's the controller.[:D]

Ken.

[tstage]

Ray,

Not to overshadow Stan's suggestion, but what if you had your locomotive address set to "3" at your LHS then bring it back home. That way you could run it on the E-Z Command on address "3" then reprogram it to another address.

With the buzz you are describing, it does, as cacole has suggested, sound like your decoder is running in DC mode. What happens if you run it on address "10" with the Bachmann?

Tom

[rayw46]

Thanks Stan, I'll try your solution.

[stanames]

Neither your locomotive or system is faulty. Strangly enough this is how it should work but there is a simple fix.

The Atlas locomotive decoder has two modes. In one mode the locomotive is silent, in the other mode the decoder uses a pulsed power that can get noiser as you increase the DCC track voltage. Some people can hear it and for othere is is masked.

The solution is to program CV 50 to a value of 8. You will have to take the locomotive to a dealer or friend why can program these high CVs as the current backmann system can not. Once set for silent mode the problem you have will go away.

Stan Ames

[cacole]

It sounds like AC voltage other than the DCC command signal might be getting onto the track. It could be a faulty Bachmann power supply or the DCC system has a faulty rectifier circuit. I'd take the Bachmann back and exchange it.

[rayw46]

Ken, that was my very first assumption. especially since I also have an Atlas B40-8 which does the same thing. Both loco's have been properly programmed per Bachmann documentation and the jumpers set to DCC. I wonder if it's possible to adapt a better 14 V. power suppy to the system?

[NZRMac]

but if the loco runs ok on another command system ( Digitrax) then it must be the EZ DCC command, either not a nice smooth power supply or it's faulty.

Ken.

[selector]

The buzzing is a problem in cheap decoders, such as the Soundtrax DSD 100LC, of which I have two. You need to tune the CV for PWM, or pulse width modulation...if that decoder supports it. Check your manual. It is CV #9 for the 100LC, but that is a sound decoder.

[Scholten]

I too have a noisy Atlas loco. The problem, I am told, is in the decoder that Atlas put in the loco. The decoder used at the time of manufacture is simply not as good as the ones available today. It is inherently noisy. I do not believe the noise adversely affects the loco, but it is a distraction.

Paul

[rayw46]

Thanks, but this has all be taken care of. Since this is an Atlas locomotive, the default address was 88, the last to digits of the locomotive number. Until I changed this, the locomoitve would not move, let alone make a sound. I reprogrammed the decoder for address 8 per Bachmann documentation. The locomotive now runs, but with the buzz. As I said, it works fine on a Digitrax system at my local hobby shop on address 8. The guys at the hobby shop, who have a great deal of experience with DCC can't figure it out either.

[cacole]

First, you have to program the decoder or the decoder's address into the Bachmann system. The defalt address in the decoder should be 3. Try telling your Bachmann to run a locomotive set to address 3 and see what happens. If that doesn't work, then you need to reprogram the Atlas decoder.

Refer to the Bachmann documentation on setting up a programming track and programming decoders.

Another possibility is that the Atlas decoder was already set to DCC and you flipped the switch to DC mode. Double-check your Atlas documentation and make sure you have the decoder set correctly.

[rayw46]

Help!!! A week ago I purchased a Bachmann E-Z DCC System. I hooked it up per instructions (very simple). I switched the jumper in my Atlas GP-40 Dual Decoder to DCC. When I give power to the locomotive there is a very audible, "buzz," similar to the buzz often heard in a flourecent light. The locomotive seems to run okay. I have tested the same locomotive on a layout running Digitrax DCC and it runs super quiet and very smooth. Bachmann customer service had not explanation, but they did send me a replacement system. Of course it did the same thing. The sound is unacceptable and I am also afraid the locomotive might be damaged. Does anyone have an answer and a possible solution (I know, ditch the Bachmann System)?