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JEReising
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 Posted - 06/11/2006 : 14:20:53
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Some time ago I was asked to participate in an experiment. Aztec’s John Claudino needed someone with DCC experience to assist getting his new MRC PNP Sound Decoder frames ready.
We took an Atlas GP40 (the board fits several other locos, I am told) and the MRC decoder/speaker and, after some trial and error, ended up with onboard n scale sound and an easy conversion.
The MRC decoder replaces the Atlas light board, and the speaker goes into frame’s milled out fuel tank.
The procedure is like other Aztec DCC conversions; you send your loco’s bare frame to John (Along with some money!) and about a week later you get back a milled frame and clear instructions on how to proceed.
The GP40 disassembly is straightforward. If you’re nervous about it, take some pictures to aid in reassembly, but it shouldn’t be a problem.
The very first thing to do is to put some tape on the frame in the area where the contacts hit the board. Although on close inspection it looks like there is no chance of contact, failure to do this will cause a major problem (DON’T ask how I know!).
The rest of the reassembly is as easy. Take your time and route the wires as shown in the accompanying pictures carefully.
The clear insulation is said to be fragile but I had no problems with it. I’d be particularly careful to insure the wire stays in the milled channel near the spring power pickup – repeated abrasion here would not be a good thing. Once the shell is back on this should no longer be a problem.
MRC suggests drilling some holes in the plastic fuel tank molding to better allow the sound to escape the speaker but I noticed no difference with or without the tank molding. The speaker actually fires into the bottom of the motor anyway, it has to because of the way the speaker connections are set up.
MRC includes comprehensive instructions with the decoder and when you have followed their instructions you will end up with a new dimension for your layout.
To those of you who think they might want to rout out their own fuel tank, good luck. This is not something I would tackle willingly when I can get Aztec to do it for a couple bucks. Getting the depth correct could be REALLY tricky.
I have a few caveats:
I run a Digitrax Super Chief with DCS 100 command station and DT 100 radio throttles.
Because the decoder was built for MRC’s own Prodigy DCC system there are some incompatibilities. My DT 100 has functions 0 through 7, and they worked nicely, but MRC’s system has 19 functions. I WAS able to access them through CVs, but this is pretty awkward.
I couldn’t use the radio throttle to control the loco. It worked correctly while plugged in, but once untethered there was no response from the loco.
My GP40 has the original high speed motor, and MRC has set up their decoder to apparently apply a lot of voltage as the lowest start voltage because the loco acts like a rocketship – and apparently in this iteration of the decoder, can’t be modified. The loco takes off at 2 (of 100) on the DT 100. Programming worked but actually made it worse so I returned the CV to the original value - the lowest possible setting.
It’s kind of cool the way they have the sound set up; you advance the throttle and hear the diesel sound rev up and then the loco starts to move. Unfortunately I THINK that’s as far as it goes, the sound emulates the Diesel’s transition but then does not rev up again, and at that point because of the noise of the mechanism you likely couldn’t hear it if it did. And as you ease to a stop you hear the squeal of brakes applying.
Before this, if you’d have asked me if I wanted sound I’d have looked at you as if you were nuts. Now I admit it’s pretty neat to hear the engine idling (with occasional air compressor and other sounds), switch the bell on, give a couple blasts of the horn, and hear the prime mover rev as the loco begins to move. It IS a new dimension, and one in which I will participate.
To sum up, I think the problems I encountered are minor and will likely be dealt with as the sound decoder matures.
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Jim Reising
Visit The Oakville Sub at:
http://theoakvillesub.freehosting.net/
And on Trainboard:
http://www.trainboard.com/grapevine/showthread.php?t=99466 |
Country: USA
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txcavgr
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Posted - 06/11/2006 : 14:30:04
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Jim, that is a great post. I am going to have to try this when the track expenditures slow down a bit. Thank you.
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JEReising
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Ian_MacMillan
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Posted - 06/12/2006 : 12:15:18
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quote:
Originally posted by JEReising
Because the decoder was built for MRC’s own Prodigy DCC system there are some incompatibilities. My DT 100 has functions 0 through 7, and they worked nicely, but MRC’s system has 19 functions. I WAS able to access them through CVs, but this is pretty awkward.
This is not a compatablility issue but a NMRA compliance issue. NMRA standard docuemnts F0-F12 as the currently accepted functions on decoders. With sound decoders that are non mapped becoming more and more common, maybe you will see the standard adjusted, but for now, its not. Also, regardless of whats on your throttle, its supported, the keys are just "quick links" to the functions, and can be accessed via CV like you did.
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Conrail's Amoskeag Northern Division - Conrail Modeling and Speeder Trips
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Flying Crow
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Posted - 06/12/2006 : 14:45:30
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Does anyone have a part number for the sound decoder? Is the speaker included?
Rich
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Modeling the Alexandria & Western, a bridge line jointly owned by the KCS & SP in Central Louisiana
Houston, Texas |
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espeefan
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Posted - 06/12/2006 : 14:56:03
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Have you compared drawbar pull before/ after? Thata a sizble hunk of metal you lost for the speaker.
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JEReising
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Posted - 06/12/2006 : 16:44:22
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Flying Crow -
From the MRC web site, part # 0001636. Speaker is included.
Espeefan -
No I didn't check the tractive effort. I RARELY run only one loco; my pike is not a branch line operation. I grant you this may be an issue but not for me. And I had it leading a pair of GP35s pulling my cleaning train and there was no slowdown up the hill - and we're not talking a couple cars here, more like fifteen...NOT a light train.
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Jim Reising
Visit The Oakville Sub at:
http://theoakvillesub.freehosting.net/
And on Trainboard:
http://www.trainboard.com/grapevine/showthread.php?t=99466 |
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Aztec Mfg. Co.
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Posted - 06/12/2006 : 19:01:42
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The weight of a stock frame is 1.3 oz and after machining it is 1.1 oz.
John Claudino
aztecmfg@usa.net
[quote]Originally posted by JEReising
Flying Crow -
From the MRC web site, part # 0001636. Speaker is included.
Espeefan -
No I didn't check the tractive effort. I RARELY run only one loco; my pike is not a branch line operation. I grant you this may be an issue but not for me. And I had it leading a pair of GP35s pulling my cleaning train and there was no slowdown up the hill - and we're not talking a couple cars here, more like fifteen...NOT a light train.
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Edited by - Aztec Mfg. Co. on 06/14/2006 07:40:54 |
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JEReising
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Posted - 06/13/2006 : 08:27:14
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A bit of further info.
I futzed around with the CVs for acceleration and deceleration last evening and managed to get substantially improved performance from the unit. I would still prefer to be able to lower the start voltage but you can't go negative, and the acceleration seemed to at least delay the response so the GP40 matches up with it's running mates a lot better.
I suspect much of the problem comes from the high speed motor the unit came equipped with but that's something we all have to live with at present.
The more I run the unit the more I like it. It gets to be addictive, and when you turn it off there seems to be something missing.
Only thing that bothers me is what 20-30 of these would sound like...:-)
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Jim Reising
Visit The Oakville Sub at:
http://theoakvillesub.freehosting.net/
And on Trainboard:
http://www.trainboard.com/grapevine/showthread.php?t=99466 |
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Country: USA
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Robyn Watkins
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Posted - 06/13/2006 : 09:46:22
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Jim,
Do you happen to know if your decoder is just a test sample and MRC will offer thicker insulation for wire to the speaker?
Why I ask is that it is probably the one thing that I don't like about the decoder. I guess I'm worried about any wear whenever one takes the body shell on and off.
Thanks again,
Robyn
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| "Stop stop talking 'bout who's to blame when all that counts is how to change." James -"Born Of Frustration". |
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JEReising
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Posted - 06/13/2006 : 10:35:22
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Robyn,
As far as I know, these are production decoders.
And I really don't think the insulation is a factor. Although it is clear, it's actually pretty rugged.
I've worked with the really tiny stuff used for wiring Surface Mount Technology LEDs (for ditch lights) which uses the same type coating only thinner, and I've mistreated that pretty badly and never had a problem.
The shell, after all, is plastic and is not a knife edge; sliding abrasion should not be an issue unless you plan on moving the shell 50 times. And I don't know about you, but once I get one of these guys in place, the only reason the shell comes off is for serious loco maintenance - maybe once a year if it's well used.
To address a comment from the other thread, the MRC chip HAS different horns and noises other than what is set up as default. I just haven't had time to monkey with them as yet. This is one of those situations where having a Prodigy system would be a plus with it's additional functions. I'm sure I can change them using CVs, I just need to take the time to get it done.
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Jim Reising
Visit The Oakville Sub at:
http://theoakvillesub.freehosting.net/
And on Trainboard:
http://www.trainboard.com/grapevine/showthread.php?t=99466 |
Edited by - JEReising on 06/13/2006 10:41:41 |
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pray59
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Posted - 06/13/2006 : 11:26:27
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Having had one of these decoders in my hands, I decided I don't care for the solid wire either. If I was to use this decoder I would just solder some new 32AWG stranded wires cut to lenght, after install and testing with the solid copper wires.
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SD70BNSF
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Posted - 06/13/2006 : 13:47:00
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Thanks for the write-up Jim. That does sound (pun intended) cool. I have a couple of these Atlas GP38/40s sitting around. I'll have to order me up one of these decoders, then send in my frame to Aztec. I realized Digitrax is probably up to their production elbows with their new HO sound system. I just hope this takes off and they get into the act in N Scale!
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Chris Zygmont
Rush Island & Western -- Blog of my N Scale Layout
Member of MVNS
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Country: USA
| Posts: 396 |
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sschaer
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Posted - 06/15/2006 : 01:39:03
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quote:
Originally posted by JEReising
The speaker actually fires into the bottom of the motor anyway, it has to because of the way the speaker connections are set up.
is there not chance to turn the speaker around ?
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have fun
sandro
CHECK OUT MY WEBSITES WWW.CP-FORUM.NET WWW.SSCHAER.ORG |
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Country: Switzerland
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biker_ray_pa
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Posted - 06/15/2006 : 02:15:17
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quote:
Originally posted by Aztec Mfg. Co.
The weight of a stock frame is 1.3 oz and after machining it is 1.1 oz.
John Claudino
aztecmfg@usa.net
Are you planning on doing other frames for the sound decoder, like perhaps the Atlas Trainmaster or the LifeLike FA-1 or C-Liner?
Ray
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Western Allegheny RR
www.westernallegheny.com |
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Country: USA
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bsoplinger
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Posted - 06/15/2006 : 03:24:32
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My loco of choice would be the 628 since I have a whole pile of them ;)
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Country: USA
| Posts: 556 |
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