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Steam Loco Start/Idle knock sound?

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Steam Loco Start/Idle knock sound?
Posted by gdelmoro on Thursday, June 22, 2017 6:22 PM

What is that knocking (sounds like metal against metal) that decoders are trying to simulate when a steam loco starts up or idles?

Gary

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Posted by BigJim on Thursday, June 22, 2017 6:56 PM

Without hearing the exact sound you are speaking of, I'm going to guess the air compressors. Kind of a Tom-Tom sound? The sound resonates in the air reservoirs.

.

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Posted by gdelmoro on Thursday, June 22, 2017 6:57 PM

Just found an MP3 via google search for steam loco sounds.  It appears to be the steam piston sound.

Gary

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Posted by BigDaddy on Thursday, June 22, 2017 7:29 PM

gdelmoro
What is that knocking (sounds like metal against metal) that decoders are trying to simulate when a steam loco starts up or idles?

I'm guessing you mean this at 0:25

http://mrr.trains.com/sitecore/content/home/articles/2017/06/video-athearn-genesis-ho-scale-class-z-8-challenger

Henry

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Posted by ATLANTIC CENTRAL on Thursday, June 22, 2017 7:55 PM

gdelmoro

What is that knocking (sounds like metal against metal) that decoders are trying to simulate when a steam loco starts up or idles?

 

That is the air compressors which provide the air pressure for the brakes. They are steam driven and come on automaticly when air pressure drops.

Large modern steamers often had two compound pumps, and they do make a loud "knocking" sound. 

If you go someplace like the Strasburg Railroad where you can watch an operating steam loco up close, you will learn a lot about the sounds and functions of the various parts.

https://www.bing.com/images/search?view=detailV2&ccid=L51mz94W&id=08BC08F7D997856DBCB6A6AFEF2C73155012422E&thid=OIP.L51mz94WRZyp6HHgIShnbAEsDI&q=steam+loco+air+pump&simid=608036374169651484&selectedIndex=16

Sheldon

    

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Posted by "JaBear" on Friday, June 23, 2017 5:06 AM

In the video I linked to in this thread, “How does a steam locomotive start up sound?” between 7.53 to 8.15, you’ll see the Westinghouse air compressor, similar to the one Sheldon linked to, start up.

http://cs.trains.com/mrr/f/13/t/263416.aspx

Cheers, the Bear.Smile

 

 

"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."

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Posted by gdelmoro on Friday, June 23, 2017 6:35 AM

YES  need to find a CV to lower it.

Gary

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Posted by ATLANTIC CENTRAL on Friday, June 23, 2017 9:29 AM

gdelmoro

YES  need to find a CV to lower it.

 

Well I'm not the DCC sound expert, but I'm not sure you will find a seperate volume control CV for that sound. In real life they are rather loud, I have watch people be seriously startled when standing next to the loco at Strasburg and the air pump starts up.

Sheldon 

    

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Posted by 7j43k on Friday, June 23, 2017 10:22 AM

ATLANTIC CENTRAL
 

Well I'm not the DCC sound expert, but I'm not sure you will find a seperate volume control CV for that sound. 

 

Tsunami 2 has a separate volume control for the air pump:  CV 132

 

Ed

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Posted by gmpullman on Friday, June 23, 2017 12:24 PM

7j43k
Tsunami 2 has a separate volume control for the air pump:  CV 132  

And Broadway Limited's Paragon 2 and 3 is CV 143. 0-255 range, 128 is default.

http://www.broadway-limited.com/support/manuals/Paragon%203%20Steam%20manual.pdf

Page NINE.

Does the OP know what kind of decoder we are looking for???

Ed

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Posted by rrinker on Friday, June 23, 2017 4:40 PM

ATLANTIC CENTRAL

 

 
gdelmoro

YES  need to find a CV to lower it.

 

 

 

Well I'm not the DCC sound expert, but I'm not sure you will find a seperate volume control CV for that sound. In real life they are rather loud, I have watch people be seriously startled when standing next to the loco at Strasburg and the air pump starts up.

Sheldon 

 

 LOL I said the exact same thing in the Electronics section without having seen this - about seeing people startled at Strasburg.

                               --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by gdelmoro on Friday, June 23, 2017 5:54 PM

Well that's a good question Ed, It's a BLI Paragon 2 Light Mikado. I don't really know what decoder they use.  I think they used to use QSI but i heard that recently they have been making their own.  My loco is a  2016.  

Gary

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Posted by gdelmoro on Friday, June 23, 2017 5:57 PM

Now that the discussion is about decoders and not prototypes i moved it to DCC & Electronics

Gary

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Posted by rrinker on Friday, June 23, 2017 6:12 PM

Paragon 2 and Paragon 3 are BLI's own decoders. Plain Paragon is QSI.

              -Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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