# Decoder for Accucraft D&RGW #50



## rdamurphy (Jan 3, 2008)

What would be a good decoder/sound setup for an Accucraft D&RGW #50 diesel?

Does it really need a large scale decoder, or will an O Gauge decoder work as well?

What kind of sound? It's a Cat engine, but it also has side-rods, something similar to the Bachmann 45 Tonner for sound, perhaps?

It's kind of funny, the thing puffs like a steam loco...

Thanks in advance for everyone's input!

Robert


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## East Broad Top (Dec 29, 2007)

Zimo makes a good gas sound that works well for the Davenport. I just put one in my LGB version of that loco. It sounds pretty good, and the Zimo motor control is top drawer. 

Here's a YouTube video where you can hear the sound: (Not mine, but one of a few I listened to before making my choice.)






Send Dan Pierce a PM; he'll get you set up with what you need. Zimo makes a few different decoders with different current capacities. I used the smaller for the LGB unit since it draws just a little bit of current and I'm using it as a yard switcher. I don't know if the Accucraft unit draws more because it's heavier or not. 

Later,

K


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## Greg Elmassian (Jan 3, 2008)

Try measuring the current of the loco under stall conditions on DC... That will help you.

You might get away with a 2 amp decoder, the Zimo's are good here, they give you an honest 2 amps.

Other 2 amp decoders can be unreliable near their maximum.

Greg


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## rdamurphy (Jan 3, 2008)

I believe I've seen how that's done on your website, Greg?

Thanks for the youtube video, Kevin. Sounds good, have you seen the youtube video of the prototype out at the CRRM?

Robert


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## East Broad Top (Dec 29, 2007)

I did see that. It's largely what convinced me the Zimo sound was "close enough" for what I wanted. The only thing I want to figure out with the sound file is how to adjust the point at which the motor sounds transition from one speed to another. The way it's set up, the motor is at full RPM about midway through the throttle. It appears to be tied to the motor RPM as opposed to speed step, but I'm having trouble reading the manual to find out how to tweak that. It's a custom sound file, so I'm not sure what parameter I should be looking at. (I should probably give Dan a call at some point and ask him...)

Later,

K


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## Dan Pierce (Jan 2, 2008)

The current ratings for the Zimo decoders are:
MX645 1.2 amps total but will take a 2.5 amp surge
MX645P22 1.8 amps total
MX699 6 amp total and 10 peak amps

The total rating is for motor, lights, sound servo, smoke. None of these need a heat sink.
The Davenport (D&RG #50) does need a coded file and there is a $25 for MX645 and $35 for MX699 decoder at Trainli.com
Small decoder has 1 input pin, the largescale have 3 input pins.


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## Greg Elmassian (Jan 3, 2008)

On the sound file, Kevin you cannot do what you want with CV's you need to change the sound file, and you do not get the source. 

Dan, correct me if I am wrong. Not being negative, just clear in what the situation is.

Greg


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## Dan Pierce (Jan 2, 2008)

There is a test drive (CV302=75) and must be 5 meters with no curves/slopes for fine tuning the decoder in an engine. Not sure if this will help Kevin.


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## Beddhist (Dec 17, 2013)

Kevin, try to contact the author Heinz Daeppen directly. Link is on the Zimo sound page.


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## rdamurphy (Jan 3, 2008)

I was thinking last night, I made a custom sound file (coal shoveling) for my QSI Magnum, perhaps I might just purchase a Titan for one of my K's, and use the Magnum in the 50? I could make the custom sound files from the YouTube video (Unless I can convince the CRRM to let me make my own recordings), of the diesel engine sound and the whistle. They both seem easy to loop, only question I have is if the engine sound would speed up and slow down with the Decoder's speed setting, or if it would be necessary to have separate speed files? The 50 doesn't have a notched throttle, and is a diesel-mechanical, with a fixed transmission. If I'm not mistaken, it doesn't have more than one gear? Just a direct drive.

Robert


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## Dan Pierce (Jan 2, 2008)

I thought the Davenport was a gas engine.


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## Greg Elmassian (Jan 3, 2008)

a custom sound is just a loop played like on a iPod.... no relationship with with speed, load, etc.

You might try the new RDC file recently released.

For the low current I believe it draws, I'd go the Zimo unit, I'm happy with mine in my Berlyn rail truck

Greg


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## East Broad Top (Dec 29, 2007)

Dan Pierce said:


> I thought the Davenport was a gas engine.


In terms of the Zimo sound, it's listed as a recording of a gas engine. The prototype D&RGW loco has a Caterpillar D-1700 diesel. To Robert's point about the transmission, the "standard" transmission for Davenport's diesel-mechanical locos was a 4-speed forward/reverse transmission, according to what I could dig up on the web. I'd presume this loco would use that. 

Later,

K


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## rdamurphy (Jan 3, 2008)

Yes, Wagner Caterpillar in Denver rebuilt the engine for the museum at no charge, since apparently it's the oldest Cat engine still running in the US. It would make sense for it to be a fluid coupling with a four speed. 

So, how would that work with a DCC decoder, since the engine RPM's would vary with the gear shifting and with load?

Robert


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## Greg Elmassian (Jan 3, 2008)

there are sound files that have the gear shifting. The one I have in my Zimo in my rail car has 4 speeds and you can hear the driver shift, and the rpms change just right.

The new RDC Q3 file for the QSI Titan might work, weren't they gas engines with a 4 speed auto?

Greg


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## East Broad Top (Dec 29, 2007)

The RDCs used 2 6-cylinder Detroit Diesels (one for each truck). That might not be a bad option to look into. I would presume QSI's sound file recorded just one of these engines, and then is using the ability to set up dual prime movers to get the sound of both working for the RDC. 

I didn't see way to preview the sound, though, and I think the QSI software is still such that you need to download the file to your decoder to actually hear the prime mover or chuffs. (Greg, please correct me if they've upgraded this. It was last summer when I last programmed a QSI decoder, and they like to upgrade things regularly.)

Alas, YouTube videos of RDCs aren't much help in terms of a detailed comparison to #50.

Later,

K


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## rdamurphy (Jan 3, 2008)

Those wouldn't sound right, I don't think. The Detroits were two-cycle diesels, I believe the Cat would be a four-cycle, but I'm not sure...

I would think it would be "close enough", though. 

Robert


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## rdamurphy (Jan 3, 2008)

From reading another post and doing a bit of research, why couldn't I use a D408 to run the motor and lights, with the 4Amp rating, it shouldn't have any problem at all, and then a simple sound decoder, with nothing but engine, bell, and horn?

Seems like that solution would solve all of the problems, if I can find a sound decoder that's suitable...

Thanks, 

Robert


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## Dan Pierce (Jan 2, 2008)

I prefer a single board that does everything, especially in a small loco where there is not much room. Weight, board and speaker can take up lots of room.


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## rdamurphy (Jan 3, 2008)

I'm a bit concerned with using a 2 amp decoder in the Accucraft locomotive. It weights about 5 or 6 pounds and has a huge motor in it.

Thanks,

Robert


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## rdamurphy (Jan 3, 2008)

Any thoughts on the Digitrax DH465 4 Amp decoder?

Thanks,

Robert


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