I have stayed away from DCC partly because I did not understand it, partly because I did not want to complicate things, partly because of the extra expense. Now I understand the very clever principle behind it and am not so against it. I still have no experience with DCC and own no DCC equipment. The point is that while reading about it I read that running a DCC loco on DC could be damaging and wondered if perhaps my Aristo-Craft 2 8 8 2 mallet could have a DCC decoder installed without me knowing it. I prefer not to disassemble it unnecessarily. Hence the question. Can one know if a locomotive is equipped with a DCC decoder without disassembling it?
Can one know if a locomotive is equipped with a DCC decoder without disassembling it?
trainstrainstrains
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The Sierra board is not a DCC-native board. I'd say it's almost certain this loco does not have a DCC decoder onboard. In looking at the wires going to the Sierra, you've got the speaker wires on the upper left, power from the track/motor to the upper right, and I think the three wires in the lower right will go to the external volume switch.
Later,
K
Later,
K
I doubt that you can use just an ohmmeter to determine this - if you just measure at the power pickups, an analogue loco with a sound system (but no DCC decoder) will give you a similar reading than a loco with a decoder.I guess that it was just too much effort for Greg to simply put an ohmmeter across the wheels on a DCC engine and report back.
None the less, we had a Club meeting tonight and one of the guys runs DCC. He also thought there should be an obvious difference when read with an ohmmeter and said he would give it a try and report back to me. I hope he remembers because with ~50 people there tonight, I'm having a hard time remembering who it was.
Alternatively, there are probably several here would could perform this little test and let the group know the outcome.
Knut
That won't help - you would still depend on the person installing the decoder to affix the sticker and even if they do - stickers have a tendency to fall off eventually.
If you had a DCC system you could read out the manufacturer and usually the model and version of the decoder if there was one - but then we wouldn't even have this discussion.
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Sorry TTT, I was so busy fending off Todd's personal affronts and pouting since no one else believes in his ohmmeter theory (which by the way would need to be proved with quite a few different decoders and decoder/sound board combinations).
Yes, normally the Aristo socket is in the boiler, but with a sierra sound board present, very doubtful you would have a DCC decoder, since for them to co-exist, the sierra would need the "speed" input filtered. Also the fact that the loco starts moving at 2 volts, means it's almost certain no decoder is present, since MOST need a bit over 5 volts.
If it was me, I would not pull it apart, but just for reference, I have a specific page on how to disassemble a Mallet:
http://www.elmassian.com/trains/motive-power-mods-aamp-tips/aristo-motive-power/mallet/disassembly
(easy to find on my site under large scale... motive power... aristo... 2-8-8-2)
![Image]()
Socket is on the right board in the picture below, 2 small rows of pins
![Image]()
Regards, Greg
Yes, normally the Aristo socket is in the boiler, but with a sierra sound board present, very doubtful you would have a DCC decoder, since for them to co-exist, the sierra would need the "speed" input filtered. Also the fact that the loco starts moving at 2 volts, means it's almost certain no decoder is present, since MOST need a bit over 5 volts.
If it was me, I would not pull it apart, but just for reference, I have a specific page on how to disassemble a Mallet:
http://www.elmassian.com/trains/motive-power-mods-aamp-tips/aristo-motive-power/mallet/disassembly
(easy to find on my site under large scale... motive power... aristo... 2-8-8-2)
Socket is on the right board in the picture below, 2 small rows of pins
Regards, Greg
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I am not trying to read anyone's mind but perhaps the "problem" is that to some of us the world of DCC can be very confusing - especially when trying to deal with unknown products.
As I understand it DCC is intended to be a universal system but clearly LGB's Serial and or Parallel MTS is not exactly DCC compatible. Beyond that I happen to have acquired a Digitrax DCS200 a couple of MRC Power 8's and an assortment of LGB, Massoth, Digitrax, MRC and NEC decoders some of which power locos or coach lights or various digital or analog sound systems.
Since they are my trains it never occurred to me to mark whatever it was that I put in the various locos - until I noticed one of my PRR Forneys ran a lot slower than the other.
I figured that something was broke so i took it apart only to discover that I had put an LGB decoder
in the loco and a Digitrax or NEC decoder and LGB analog sound board in the tender. Since the other Forney did not have any decoders it naturally ran a lot faster. Now I've got a lot of work to once again put the decoder in the loco and the decoder etc. in the tender.
When I saw this topic I thought how great it would be if I had a programming track that could tell me if and what brand and model of decoders might be in anything I put on it.
For me it does not matter which brands are best because I want to put a fully MTS compatible decoder into an LGB loco but I'm going to use a cheap decoder of whatever brand in an old Thomas the Tank or Lionel 0-4-0 - or cheap and small to dim the lights in coaches or control an inexpensive analog sound system.
The truth is that I don't know enough about DCC to even know what questions to ask and I am probably not alone. For that matter I don't know of any MTS or DCC G Gauge layouts running within a couple hundreds of miles or anyone running Digitrax G Gauge anywhere.
I don't think anyone was trying to be malicious or aggressive as much as that clearly there are various different approaches to answering the question - any of which might or might not have answered the question as it was intended.
Over the years when it comes to DCC I have often been told to buy and read a book (again a couple of days ago). I don't like reading technical books and would probably forget what I read as fast as I read it but IF there was a book on now to use and run various mixtures of LGB, Massoth, Digitrax, NEC, MRC, Zimo and or other brands at 24VDC up to 8 amps or more I WOULD buy it. Perhaps someone will someday publish "DCC for Dummies" and I would be in line to buy it.
Cheers,
Jerry
As I understand it DCC is intended to be a universal system but clearly LGB's Serial and or Parallel MTS is not exactly DCC compatible. Beyond that I happen to have acquired a Digitrax DCS200 a couple of MRC Power 8's and an assortment of LGB, Massoth, Digitrax, MRC and NEC decoders some of which power locos or coach lights or various digital or analog sound systems.
Since they are my trains it never occurred to me to mark whatever it was that I put in the various locos - until I noticed one of my PRR Forneys ran a lot slower than the other.
I figured that something was broke so i took it apart only to discover that I had put an LGB decoder
in the loco and a Digitrax or NEC decoder and LGB analog sound board in the tender. Since the other Forney did not have any decoders it naturally ran a lot faster. Now I've got a lot of work to once again put the decoder in the loco and the decoder etc. in the tender.
When I saw this topic I thought how great it would be if I had a programming track that could tell me if and what brand and model of decoders might be in anything I put on it.
For me it does not matter which brands are best because I want to put a fully MTS compatible decoder into an LGB loco but I'm going to use a cheap decoder of whatever brand in an old Thomas the Tank or Lionel 0-4-0 - or cheap and small to dim the lights in coaches or control an inexpensive analog sound system.
The truth is that I don't know enough about DCC to even know what questions to ask and I am probably not alone. For that matter I don't know of any MTS or DCC G Gauge layouts running within a couple hundreds of miles or anyone running Digitrax G Gauge anywhere.
I don't think anyone was trying to be malicious or aggressive as much as that clearly there are various different approaches to answering the question - any of which might or might not have answered the question as it was intended.
Over the years when it comes to DCC I have often been told to buy and read a book (again a couple of days ago). I don't like reading technical books and would probably forget what I read as fast as I read it but IF there was a book on now to use and run various mixtures of LGB, Massoth, Digitrax, NEC, MRC, Zimo and or other brands at 24VDC up to 8 amps or more I WOULD buy it. Perhaps someone will someday publish "DCC for Dummies" and I would be in line to buy it.
Cheers,
Jerry
Knut, like so much around here, that is just speculation until someone tries it out to see.
The reality is the sound system has virtually no effect on the ohm reading for the analog engine.
I don't know why some have such an adversion to trying this simple test.
USA F3:
Motors and Sierra off - ohmmeter reads infinity. (No lights anymore)
Sierra on, motors off - ohmmeter reads 5.23 megaohms
Sierra off, motors on - ohmmeter reads ~54 ohms, but does drift some.
Sierra on, motors on - ohmmeter still reads ~54 ohms.
If in fact the dcc decoder provides a reading similar to the sound system, as you suggest, it is relatively easy to be sure that the motor is switched on and that the meter contacts are good; and most anyone could tell the difference between megaohms and double-digit ohms on the scale in support my premiss.
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Jerry:
You may want to Google "dcc for dummies".
Before I decided to go with G-Scale Graphic's RailBoss 4, I did a bunch of research and some of those resulting sites were used in part as my sources. For my needs, DCC was an expensive and relatively complex sledgehammer for the small tacks that I needed to drive.
Mark
You may want to Google "dcc for dummies".
Before I decided to go with G-Scale Graphic's RailBoss 4, I did a bunch of research and some of those resulting sites were used in part as my sources. For my needs, DCC was an expensive and relatively complex sledgehammer for the small tacks that I needed to drive.
Mark
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Hi Mark,
My first thought was "Why didn't I do that?"
When I saw your post I did Google it but the first thing I noticed was that the books did not seem to address mixing and matching the various brands of equipment.
"For my needs, DCC was an expensive and relatively complex sledgehammer for the small tacks that I needed to drive." Pretty well defines my position.
I don't have any need for (or desire to know) 99% of what DCC can do.
All I am really interested in is:
1. Can I use an MRC Power 8 to power a Digitrax DCS200?
2. What else would I HAVE to own to use these to program Digitrax and other brands of decoders?
3. Which brands of Central Stations & remotes can ring the bell, toot the whistle, speed up and slow down LGB locos with factory decoders and LGB, Massoth, Digitrax, NEC, MRC and ZIMO decoders and how compatible with Serial and Parallel commands are they?
If I was new to the hobby and new to DCC it would be simple - pick a favorite brand and stick with it. In my case I am putting the cart before the horse. I already have the trains and assortment of decoders so I am looking for what will work with what I already have.
From what I could tell the books Google found seemed to either ignore brands entirely or be brand specific. If anyone knows different I would like to know (here or privately).
The attraction of the DCS200 and Power 8 is the 8 AMP CAPABILITY and the fact that I bought them years ago (I forget why) and they put out a lot more amps than my LGB Central Stations and LGB Boosters plus I already have enough LGB remotes.
I didn't mean to hijack this topic. I'm just looking for these answers wherever I can find them.
Thanks,
Jerry
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Jerry,
I am so much an ignoramus in the subject of DCC that I have not even seen my first decoder yet, though one is on the mail. It is from Digitrax and I intend to use it with a Bachmann DCC EZ command on N scale.
Members of another forum have assured and reassured me that pretty much any decoder will work with any DCC system today because nowadays they all comply with NMRA standards.
I am so much an ignoramus in the subject of DCC that I have not even seen my first decoder yet, though one is on the mail. It is from Digitrax and I intend to use it with a Bachmann DCC EZ command on N scale.
Members of another forum have assured and reassured me that pretty much any decoder will work with any DCC system today because nowadays they all comply with NMRA standards.
Todd,
You can't base your conclusions on just one example.
Ohmmeters are very simple instruments meant to measure the approximate resistance of a resistor or a device that behaves pretty much like a resistor.
When you start using an ohmmeter to measure any device with semiconductors, like an analog loco that has more than just the motor in it, you will get different readings depending on the specific electronics, the way they are wired and the specific ohmmeter used.
What we are trying to determine is how to distinguis between a loco with a DCC decoder (and any other electronics) and a loco without a DCC Decoder (but possibly other unknown electronics).
In the loco you are testing, the Sierra system is just connected in parallel with the motor, that's why you are getting the readings you report.
But many LGB analog locos for instance have electronic circuitry in series with the motor, so if your ohmmeter doesn't provide enough voltage to turn the semiconductors in those locos on you will get a very high resistance reading for that type of analog loco.
Good ohmmeters btw use a very low voltage for the resistance measurement specifically to not turn on semiconductors.
Knut
So..., test an analog LGB engine with a sound system turned off, then turned on and let us know what you find. It would also be nice to test one with their MTS system installed.
There are certainly plenty of people here who could provide a representative sample if some would just open their minds. This is really not that difficult and only takes a moment.
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Any time TTT, and if you do have suggestions on my site as you go, email me and I'll fix/update.
I'm going through the entire site now, but with 650 pages, it will take a while ha ha!
Greg
I'm going through the entire site now, but with 650 pages, it will take a while ha ha!
Greg
I'm not talking about a loco with a sound system.
LGB added what they call EAV early in the game. That was some electronic circuitry added in series with the motor to allow two analog locos to be independantly controlled for switching operations. It's not something that can be turned on and off.
Later they added similar electronics to many of their electric locos so that the pantographs would automatically go up and down when the loco reversed - that would have to happen in a specific sequence so that the loco would not loose power when it was running with catenary power.
Again electronics that cannot be turned on or off.
That arrangement btw allows one to run two locos totally independant with just an analog layout.
I'd be happy to measure some locos I have later this week but I doubt it will lead to anything conclusively that can be applied generally for all Large Scale locos.
I think a better bet would be some characteristic that a DCC Decoder equipped loco would have when running on an analog layout that a "pure" analog loco will not have or vice versa.
Soething like Greg's comment earlier about an analog loco starting to move at 2-3 VDC whereas a DCC equipped loco would require more like 5 or 6 volts.
If the loco wheels start turning (weith no load) at 2-3 volts, I think it's definitely analog, no DCC decoder.
However, if the wheels start turning at say 6VDC, it could either be a DCC Decoder equipped loco or a loco with EAV or other electronics but still analog.
Knut
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The issue is further compounded by the combinations of devices that can be between the motor and the track pickups.
Also, the effects of lights and smoke, which are often connected directly to the track pickups.
There's really not a simple foolproof procedure, other than actual physical inspection. Even testing on a program track, you could have a decoder, but it's not functioning, in service mode, there are 3 different types of programming and some decoders only respond to one way of communication.
To even further compound things, some accessory decoders can only be programmed on the main.
After all the locos I have worked on, and buying things used, I've found some really strange wiring.
Greg
Also, the effects of lights and smoke, which are often connected directly to the track pickups.
There's really not a simple foolproof procedure, other than actual physical inspection. Even testing on a program track, you could have a decoder, but it's not functioning, in service mode, there are 3 different types of programming and some decoders only respond to one way of communication.
To even further compound things, some accessory decoders can only be programmed on the main.
After all the locos I have worked on, and buying things used, I've found some really strange wiring.
Greg
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Move over for another ignoramus.
Perhaps the biggest contradiction is when you start mixing LGB and Massoth decoders with other brands. My personal experience has been that I cannot trust a brand A central station (some call them central stations while others call them something different) to properly program brand B decoders.
You mentioned that you have a Digitrax decoder. Around here the hobby shop and most DCC users (none are G Gauge) happen to have and use Digitrax products and are quite happy with them but I don't know anyone using Digitrax products in G Gauge especially in combination with LGB and Massoth (which I believe includes the majority of large scale DCC (MTS) users).
I think it started with G Gauge (LGB) not quite complying with NMRA standards. Even to the point that Large Scale (G Gauge/Scale) trains run backward when compared with HO etc. even though both run on DC voltage (Bachmann G Gauge locos usually have a voltage polarity reversing switch). I do not wish to confuse YOUR topic but you and I just happen to already have Digitrax decoders and I don't recall Digitrax ever being seriously discussed in any detail here on MLS (or any other Large Scale forum). I may well be, and hope I am mistaken as I have never paid a lot of attention to DCC or MTS in the past so I happily describe myself as a fellow ignoramus when it comes to DCC.
The truth is that I am a happy ignoramus who would like to know a bit more about DCC and MTS but not too much more about it - just enough to run the train, ring the bell and blow the whistle - without having to learn too much about brands A, B, C, D, X or whatever.
Perhaps your biggest issue would be to be sure that your decoder can handle the power (amps) of your locomotive in that many decoders are intended for much less power (HO, N and Z gauges) than the typical G Gauge locomotives and trains. Since the decoder is already in your locomotive it most likely is the right one for that locomotive.
Jerry
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Turning off sound in many LGB locos will not change any ohm meter readings as they used the SUSI bus to power and control the sound units. The power is taken from V+ and V-. This is one of the reasons why European mfg of decoders have a SUSI bus in decoders. Even the new ESU smoke unit is tied to SUSI.
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Jerry,
It appears your DCC dilemma is more complex than mine. Greg and K have cleared my mind, there is no decoder on my Aristo-Craft 2 8 8 2 mallet, I know for sure none of my other locomotives have decoders, as for my n experiment it will be very simple, just one mini locomotive, one mini decoder, one beginners controller.
If I like it maybe one day in the very distant future I will turn all G into DCC. It is afterall the most logical way to control trains in the 21st century. When and if I do that I will try to buy everything from the same manufacturer to have total certainty that everything will work well together.
From ignoramus to ignoramus. My suggestion to you would be
1. Open all your locomotives.
2. From what you find inside decide what you want to keep based either on quality or amount of similar decoders.
3. Buy a complete DCC system from one manufacturer for all your G scale setup. (You don't have to buy it all at once)
In other words start from scratch.
It appears your DCC dilemma is more complex than mine. Greg and K have cleared my mind, there is no decoder on my Aristo-Craft 2 8 8 2 mallet, I know for sure none of my other locomotives have decoders, as for my n experiment it will be very simple, just one mini locomotive, one mini decoder, one beginners controller.
If I like it maybe one day in the very distant future I will turn all G into DCC. It is afterall the most logical way to control trains in the 21st century. When and if I do that I will try to buy everything from the same manufacturer to have total certainty that everything will work well together.
From ignoramus to ignoramus. My suggestion to you would be
1. Open all your locomotives.
2. From what you find inside decide what you want to keep based either on quality or amount of similar decoders.
3. Buy a complete DCC system from one manufacturer for all your G scale setup. (You don't have to buy it all at once)
In other words start from scratch.
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