# Basic multiple-unit question.



## Scottychaos (Jan 2, 2008)

I still havent picked a power system for my railroad..
Im researching DCC systems and the Aristo revolution..

simple question..
Lets say you have a two unit set of diesels, that you plan to always run together as a set.
Is it possible to install only ONE reciever (and possibly only one sound card) in one locomotive,
then simply run jumper wires to the second locomotive to power the trucks?

I see one of the DCC systems has something they call "slave" decoders for multiple units..but is that really necessary?
Apart from power draw concerns, couldnt you simply hook up one decoder to four motors instead of two?
and two speakers instead of one?
I guess the only thing that would prevent this would be power issues..can the system handle it?

Obviously if this was done, the second unit couldnt run by itself..but if its always meant to part of the pair, this isnt necessarily a big deal..
basically you would be treating the 2-locomotive set as one locomotive with four motors instead of only two motors.

any thoughts?

thanks,
Scot


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## AndyC (Jan 2, 2008)

I run a set of GP-7 & A GP9 together, using a pheonix sound system with speaker in the lead unit, and it's connects with a ""Mini"" plug, to a speaker in the second unit.... Don't know about the remote systems, as I run mine on track power... 

Seems to me, if your running DCC, and both engines pick up power from the tracks, you'd need a reciever in bouth, or rewire the units, so all power pickups go to the first unit, thru thr receiver, and then redistribute power back to the second unit... But, I'm definitely no expert on electronics...


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## Greg Elmassian (Jan 3, 2008)

Scot, given a decoder of sufficient amperage capability, you can do this. Normally though the locos you run in MU draw too much for "doubling up", and MORE importantly, DCC decoders are so cheap why do this? When disconnected you then cannot run the other loco on DCC. 

The extra time and "ugliness" of having 2 large wires carrying current to the motors in the other unit, and also, you would want to carry the track pickups from the slave to the master. Now you have 4 wires between locos. 

You can buy decoders without sound for $50. 

It really makes no sense to do this with how inexpensive the per loco cost is. 

Regards, Greg


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## Scottychaos (Jan 2, 2008)

Thanks Guys! 
makes sense.. 

I would probably be doing battery power, not track power.. 
I will have to dig into the capabilities of some decoders, see what they can handle.. 

I take it *three* units on one decoder would be quite out of the question then? 
sounds like it.. 

If two units on one decoder can work, I would much rather have a wire between units than an extra decoder.. 
$50 might not be much..once..but im thinking several multiple units sets, now you are talking about a $200 difference.. 
thats substantial. 

thanks, 
Scot


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## Greg Elmassian (Jan 3, 2008)

Yep, probably out of the question. 

There are some decoders rated 10 amps like airwire, but they are rated at 12 volts, so maybe only 5 amps realistically at normal voltages. 

I do agree it can add up, if you want to put up with it. If you are running battery power, then you would probably be using Airwire's decoders. 

I think you can try 2 locos on one decoder, but you will most likely be limited to lower speeds and light loads... no smoke units, and minimal lighting. 

What locos were you thinking of? 

Greg


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## Scottychaos (Jan 2, 2008)

Greg, 
I have several sets planned for the next 10 years or so. 

Two USA Trains Alco PA's. 
an ABBA Set of Aristo FA's (but only two are powered, two are unpowered) 
the two sets above I already own..in addition, I also plan to make: 

A 2-unit set of USA SD40-2's, painted in my own railroad's name and colors. 
A 2-unit set of USA SD40-2's, custom painted in Conrail colors. 
And possibly a 3-unit set of USA GP38-2's, painted up for the LV. 

that will keep me busy for the next 10-20 years.. 

Im thinking I might want to keep a track powered loop just for diesels.. 
I already have some steam locos converted to battery power, and overall I like battery power much more than track power. 
but im thinking track power might be much easier for the multiple-unit diesels.. 
actually..for the track powered loop, I might just go with a power pack hooked up to the rails!  
at least initially.. 
But eventually I will probably want to go with something like Airwire or Aristo revolution for the entire railroad.. 

thanks, 
Scot


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## Greg Elmassian (Jan 3, 2008)

Track power will show itself in long running times, longer trains, the ability to use lighted passenger cars with impunity, smoke units, and actually sound systems, since they can draw significant power too. 

You have many more options in track powered DCC and the cost will be lower per loco. 

If you want battery DCC, your choice is pretty much Airwire alone, although you can get throttles from NCE and other receivers/decoders from QSI. Unfortunately, this system is not pure DCC, so recent changes by CVP have limited some functions and also complete compatibility with the NCE product. 

If you don't need a lot of features, and are willing to give up about half of the functionality of DCC, you can consider the Revolution. Your choices in quality sound systems goes to heck though, you basically only can use the Phoenix. The capabilities of consisting are clunky, but workable. 

Don't count on the Revolution being compatible for 10-20 years though, just use the previous history of Aristo, don't take my word alone. Do count on DCC being there and all your stuff continuing to work. 

Regards, Greg


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## Cougar Rock Rail (Jan 2, 2008)

Hi Scot, 

Just another thing to consider: If you want to run multiple locos from one decoder, while it is doeable as Greg outlined, you lose the ability to adjust each loco individually to match the others. So while in theory three GP40's should run the same, it's possible if from different runs (diff motors), replacement motors over time, wear & tear etc., you may want to adjust them over time. Also, if you put a decoder in each one you can then mix/match loco types obviously. 
One other option down the road--if you want to stay with battery power for some locos but still have the advantage of DCC, soon you will be able to get the Massoth DRC300, which is a receiving interface device that will let you run your loco on track or battery using any DCC decoder. Similar to the airwire idea but better because you can use any decoder and the navigator handheld can also run your DCC system or act as it's own with up to eight locos on battery. So you can have both...some battery, some track DCC running at the same time and being able to control them all with the same wireless handheld. 

Keith


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## Greg Elmassian (Jan 3, 2008)

Forgot about that unit. 

Keith, what's approximate street price on a navigator throttle and also the DRC300 ... nice idea. 

Greg


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## lownote (Jan 3, 2008)

I'll just add my two cents: there's no reason to do it that way you suggest, unless the $50 bucks is a deal breaker. You can buy one decoder with sound and all the bells and whistles, and a second cheaper decoder for the second loco. Here's a really easy way: give them different addresses to start. Then speed match them, setting the start, middle and hi voltage so they run match. Then give them both the same address. Once they are speed matched, and share an address, they will always run together. Easy! I have and LGB 0-4- and powered tender that I set up this way--speed matched them, then gave them both the same address. As soon as the snow melts. I have a couple 2-8-0s I'll do the same to.


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## Greg Elmassian (Jan 3, 2008)

Consisting is so easy, why change addresses? 

I can consist 2 locos faster than you can change their addresses to be the same. There's also a downside to what you did, the backup light on the lead engine will still go on in reverse and the headlight of the last loco will still go on in forward. There's also the lack of control of sound systems, i.e. the horn on both locos will sound instead of just the lead one. 

Speed matching is really independent of consisting, i.e. you can use any of the 3 "methods" of consisting after speed matching. 

I only bring this up in order to not make the error of saying consisting is difficult, and you need to set them to the same address. Your personal choice is fine. 

Regards, Greg


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## Michael Glavin (Jan 2, 2009)

Is it not plausible to use the NCE G-Wire Pro-Cab with G-Wire/decoder and or Airwire decoder equipped battery powered loco's and additionally use the wireless feature of the Pro-Cab to talk to the wireless NCE DCC receiver and run ANY decoder equipped loco on DCC and track power? 

I have the NCE equipment, but have yet to install the DCC stuff on a permanent layout, that said it was my understanding I could mix and match as I eluded to above... 

Michael


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## Greg Elmassian (Jan 3, 2008)

I think you are asking if the Gardenwire cab will talk to the "regular" NCE DCC system, which is track powered and has one or more base stations. 

For the confused, the CVP/Airwire/Gardenwire system has the cab "talking" directly to a receiver in the loco. 

"normal" DCC systems have cabs (wired or wireless) communicating with a "central station" or "command station" which then generates the DCC commands and puts them to the rails (there is a booster involved which may be internal or external) 

So to answer what I think you are asking Michael, no the Gardenwire transmits signals meeting the specification of the Airwire system, directly to the loco. 

The "normal" nce system and wireless cabs uses a completely different, bi-directional protocol. 

Regards, Greg


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## Michael Glavin (Jan 2, 2009)

Greg, 

If I understand you the G-Wire Pro Cab is good for the G-Wire RX's and AirWire decoders only? Or at least in wireless mode only; as they do have the ability to be hard wire connected via duplex connector. 

For wireless DCC another Pro Cab R is required with a radio base station. 

I'm going have to dig a little deeper, I have the NCE PH-Pro R system (in the box) and two G-Wire Cabs which I have been using. Somewhere along the line I must have miss read and or miss-understood the compatibility of same, NOW disappointed..... 

Michael


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## Greg Elmassian (Jan 3, 2008)

Right it only works for Airwire protocol. I have never tried to connect it hardwired... I can try that out, have one here... 

Well, nothing is stated anywere that the Gwire is compatible with the NCC wireless... Airwire is not bidirectional protocol, the NCE wireless is. Many people do make this assumption because they look the same, and they both operate in the 900 MHz band. 

I'll try connecting the Gwire into my wired systems (Have G scale and Z scale NCE DCC).... 

Greg


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## Axel Tillmann (Jan 10, 2008)

Posted By Greg Elmassian on 03 Feb 2011 09:48 AM 
Forgot about that unit. ..........


Greg 
That's not the only one you forgot about. 

If you are in the market for track powered multi train solution your best choice is DCC and Zimo's MX32 cab (which of course requires ZIMO's central station) is currently the best on the market I have seen. Full color display and all the nice features that I already come to appreciate in the past. Now If you don't want to send command signals over the track but over the air and you still want to use DCC decoders than ProLine TrainControl is a very good handheld option. Of course ProLine's TrainControl works also for battery operated systems.









Needless to say TrainControl is a full color touch panel handheld with only one a few operating elements such as the single knob speed control. TrainControl is bi-directional and with the DCC receiver you can control any DCC engine and track receiver. If you don't like the advantage of DCC then TrainControl offers a full set of engine and switch wireless receiver/decoders which do not use the DCC protocol.

I would not understand if your choice is track power why you would choose to separate the power distribution from the signal distribution except if you are intend to run more on other peoples layouts than you own or at least there is a fair mix of both type operations.

I still do not understand the appeal of battery power, but may it as it is you have your choice and we have the product
ZIMO DCC for pure DCC installations
TrainControl with DCC and potentially + ZIMO DCC (with the combination you can run native DCC and you can run wireless DCC and friend's layout)
TrainControl with RF receiver/decoder NON DCC track or Battery powered setups.


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## Greg Elmassian (Jan 3, 2008)

Axel, so there is a receiver that will connect to any DCC decoder? 

Do you have a link where I can read more? How much money? What voltage range can be used? I assume either battery or track power of course. 

Greg


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## Axel Tillmann (Jan 10, 2008)

I am still translating the catalog but the product I am referring to is:

* 6020005
DC Function Decoder 2.4 GHz*
The DCC function decoder "replaces" a conventional
DCC central station. This decoder is
inserted between the track source for data/power
and the existing DCC decoder.
The function decoder "translates" the wireless
commands from the handheld (2010000) into
the DCC format and controls the built-in DCC
engine decoder.
All DCC equipped engines can easily be adapted
to Train Control.
T*he decoder offers feedback to the handheld
* 
The currently published price is $85. Keep in mind this receiver works in conjunction with the new TrainControl handheld which is unfortunately not cheap but of course replaces Cab and parts of the command station in the single handheld. A different concept all together.


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## George Schreyer (Jan 16, 2009)

So this thing is an onboard, one loco, receiver? How much current can it handle?


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## Cougar Rock Rail (Jan 2, 2008)

Sounds exactly like the Massoth DRC300 to me...


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## Axel Tillmann (Jan 10, 2008)

Posted By Cougar Rock Rail on 06 Feb 2011 02:23 PM 
Sounds exactly like the Massoth DRC300 to me... Obviously it is not because it is designed to work with the TrainControl handheld as pictured above


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## Axel Tillmann (Jan 10, 2008)

Posted By George Schreyer on 06 Feb 2011 02:13 PM 
So this thing is an onboard, one loco, receiver? How much current can it handle? The DCC receiver doesn't have to handle any current because it only translates the RF commands to the DCC decoder. With that said there are also complete RFR + engine decoder handeling 5A.


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