HO DC engine buzz on DCC track

[KennyK]

Can anyone tell me if there is anything that can be done to quiet the buzz sound from a DC diesel engine running on a DCC track? I have 2 Bachmann controllers (one for DCC and the other for DC) connected together with the Bachmann cable. The DCC diesel engine are very quiet, but the DC diesel engines I recently bought work good, but buzz when stilling still.

Thanks

[Massey]

That is what they do when they are on DCC. There is nothing you can do and you should not leave a DC engine on a DCC track when not in use. The DCC system puts about 14V AC to the rails at all times. The DC engine is picking up this 14V and it is going right to the motor. This causes the motor to vibrate at the freq of the DCC system, and since current is passing through the motor the motor is generating heat.

A DC engine can run on DCC tracks do to a feature called 0 streaching. What happens is the DCC command station sends a long packet of 0s down one of the rails. This packet of 0s changes the potential between the rails for a few microseconds which is enough time to cause the DC motor to move. The frequency of the packets and the rail they are send down is what changes the direction and speed of a DC loco on DCC tracks.

Massey

[deboardfam]

Toss a decoder in it if its possible. :-)

[tankist]

install decoder, ASAP

[NIMT]

Yes what you do to quiet it is install a decoder!!!! Like yesterday

[tjcruiser]

Massey had a good explanation of the "zero stretching" signal that's used to let a DC loco operate on a DCC signal. That said, this is a dangerous work-around, and may ultimately fry your DC motor. I'd shy away from doing this.

Here's some DCC / zero stretching background ...

http://www.loystoys.com/info/how-dcc-works.html

TJ

[jcanfield]

This is interesting. I had wondered the exact same thing with mine.

[gc53dfgc]

I explained this over in the DCC section but DCC does not use DC current like DC which is DC current compared to DCCs AC current. The zero strecthing is what allows DC to work on DCC and I kind of hate how Bachmann says it is okay to run a DC engine on a DCC system because it will destroy the engine a lot quicker.

I have a stickied thread over in the DCC section that describes DCC isntalls into a bunch of locomotive some of them are Bahcmann Diesels like a GP 35/39 I think if I remember correctly. which that layout is the same for every current day bachmann engine. I think I have also added in a new one on doing installs on a Bachmann pancake motor PCC trolley which is similar to any bachmann pancake motored engines. I even have a DCC pre isntalled engine from bachmann I did an install on and they are exactly the same as the DC versions except for the board. I used a stock Digitrax HO size decoder but you can get simple drop in replacement boards for them so you do not have to cut into the shell like I did.

Of course I can always install the decoder for you if installing it yourself is not to your liking.