# Digitrax with QSI



## NavyTech (Aug 2, 2008)

I currently have QSI decoders instaled in my Loco and running DC and considering switching to DCC and would like to know if Digitrax will be compatible? 

What do I need?

I have a 10amp power supply that is not PWM, can I utilize this with Digitrax?

Please educate me


----------



## Greg Elmassian (Jan 3, 2008)

Yes, virtually any DCC system will work, even really old LGB stuff. 

You need to check on the power requirements of the Digitrax, it might require AC input. My NCE allows AC or DC input. 

If you are interested in Digitrax specifically, you must have encountered a dealer or individual selling it. 

If they don't know, I'd go to the digitrax site and download the manual and verify for yourself. 

If you are going wireless throttles, be SURE to get the new version, with the bi-directional communication, not the old one-way RF ones, and of course not the IR ones. 

Regards, Greg


----------



## NavyTech (Aug 2, 2008)

I am interested in digitrax because it is affordable. I am not sure what system to use as of yet but want it to work well with QSI decoder so that I do not have to add decoders to my trains. I also want to keep things simple as possible.


----------



## adelmo (Jan 2, 2008)

I just switched from Lenz to NCE 10-R Wireless set and couldn't be happier. 

The NCE cab sold me. The digitrax cab was too busy and the NCE has full 10 amps. 

Check Greg's site and play with both. Extra $ for NCE is good investment.

Good Luck


----------



## Greg Elmassian (Jan 3, 2008)

The NCE works better with the QSI. The NCE has built in "help" for the special "indexed" CV's that QSI uses for it's special features. 

You will use these when you start customizing things, like lighting effects, playing with the sound volumes of individual sounds, experimenting with different chuff rates, etc. 

Normally you have to program 2 or 3 CV's in a sequence to access these special features, but in the NCE, there is a special "program QSI" mode that takes care of this stuff for you, and makes it much more convenient. There's other special modes built in too. 

Overall, I know the NCE must be more expensive, but you only buy one system once, so the extra $150 over a Digitrax is just a one time deal. 

Regards, Greg


----------



## Road Foreman (Jan 2, 2008)

Your power supply will work fine with Digitrax as long as the voltage is not to high.. A good rule of thumb is fore the power supply voltage to be about 2 to 3 volts over the track voltage you plan to run.. This reduces the heat build-up in the DCS200.. If you go with Digitrax get the 8 amp DCS200 command/booster station with the DT402D throttle.. You will need a UR92 receiver to go with the radio throttle.. You can then get a lower cost throttle, the UT4D if you need more throttles.. 

BulletBob


----------



## Greg Elmassian (Jan 3, 2008)

I think I need to make an important distinction here... for a regulated DC power supply, you should figure on 3 volts higher on the input for what you expect on the track (DCC voltage RMS). 

For an unregulated DC or AC supply, you need to realize that the voltage of the supply will sag under load. The industry standard is 10% sag under rated max current for transformers, but this is hardly ever checked/specified in the hobby industry. 

In this case, you need to see that the voltage UNDER LOAD from your power supply is what you expect. 

I went to a regulated supply because I needed max voltage to the tracks, that's 24 from my NCE system... that means I needed 27 volts input. Well the max is also 27 volts. So an unregulated supply of 27 volts would sag at least about 3 volts under full load, so now you have 24 volts in, and only 21 volts to the rails. 

Raising the voltage of the supply, like to 30 volts, so it would "sag" to 27 was also unacceptable, because it was over the maximum input voltage allowed by the manufacturer. 


There are also other reasons, like consistency of operation, where a regulated supply has shown to be a superior solution. For me, it was the only solution that met my requirements. 

Regards, Greg


----------



## NavyTech (Aug 2, 2008)

Can you get an NCE kit that gives you the 10 power supply unit with everything you need to get the train going? I ask because it seems that shopping online for DCC systems they do not look like they include the power supply.


----------



## lownote (Jan 3, 2008)

I also use the NCE system and think it's excellent. But it's damned expensive up front 

Yes, you can use the MRC power supply with it--but I'm not sure if that's a regulated supply or not 

One thing you could do is buy the NCE system in pieces--buy the five amp system, then add the ten amp booster later--the ten amp system is just the five amp system with a booster. Or buy the five amp system, with a wired throttle. That gets pretty reasonable. If you are not running multiple long trains, up steep grades, 5 amps might be fine. Greg wants to run long trains with lights at high speed. short trains with fewer lights, lower speed equals less amps. Yes, I like having ten amps, but it'd be a shame to let the perfect be the enemy of the good. 


George Schreyer has a lot of descriptions of Digitrax on his site


----------



## Greg Elmassian (Jan 3, 2008)

No, NCE does not sell the power supply, but you can buy a Meanwell for just a few bucks, like $80. Almost any supply will do as long as it's quality and regulated.

The picture below shows the NCE 10 amp system with a Meanwell power supply. Ignore the little silver box on top.


Greg


----------



## NavyTech (Aug 2, 2008)

It looks like I will be going with NCE so now I am shopping for an online store that can give me everything I need in one order. Unfortunately there is no where here in NS that carries this stuff. It looks like next summer I will be building a new layout as I also shopping for my retirement home as well. There will be lots of changes for me in the next year or so.


----------



## Chucks_Trains (Jan 2, 2008)

I had the Digitrax Radio Super Chief and wasn't happy with it at all. For one it was rated at only 8 amps and the biggest problem was the trains wouldn't operate at a prototypical speed (read fast) as Digitrax is only capable of something like 18 volts on the rails. Large scale engines need the highest voltage available with like at least 22 volts..if you like your trains going fast.


----------



## Greg Elmassian (Jan 3, 2008)

When I evaluated DCC systems, there were a number of things I did not like with the Digitrax, what Chuck mentioned was one of them, the inability to get a higher voltage to the rails. There were also reports that you could not "hold" 8 amps. The NCE will hold 10 amps all day. I realize you may not need either right now, but who knows what the future is? 

I just found, apparently, another limitation. Many of the newer decoders use CV's over 255. The Digitrax throttles will not allow you to access these. Funny thing, the Digitrax command station, under software control of JMRI, will. 

My NCE does handle these CV's. 

Regards, Greg


----------



## Tom Bray (Jan 20, 2009)

NCE sells the PH-10R which is their Power Pro radio cab which has everything including a 10A booster, the power supply is not included though. They sell a transformer for but they want $100 for it and they don't specify the voltage output on it ... the Meanwell supply is cheaper and it is a fully regulated DC supply. If you google Meanwell 24V 10A you should find a couple of vendors for it. 

Tom


----------



## Greg Elmassian (Jan 3, 2008)

If you intend to use the full capability of the booster, I recommend the 27 volt one, but 24 volts will be good for a bit over 20 volts to the track. 

I don't think Jason runs at breakneck speeds, or runs a lot of passenger trains, so the 24 volt one will be ok. 

The meanwell was mentioned way back in this thread as well as the NCE. 

Regards, Greg


----------



## George Schreyer (Jan 16, 2009)

Both NCE and Digitrax require that you BYO power supply although Digitrax sells power supplies too, they won't support 8 amps. 

Both will work with AC or DC as an input. 

The Digitrax "duplex" throttle still seems to have problems for some people. 

I use Digitrax because it was the only system with a radio throttle in 1998 when I bought the system. However, it works well and I am not inclined to change it to something different. I use simplex radio throttles. If I want a duplex throttle, I use my iPod touch with the WiThrottle app. The app works on iPhones too and there is an Android version. You need a computer connected to the command system network running JMRI (free software, mac, pc and linux). I don't feel the need to buy Digitrax duplex throttles.


----------



## Chucks_Trains (Jan 2, 2008)

Normally you have to program 2 or 3 CV's in a sequence to access these special features, but in the NCE, there is a special "program QSI" mode that takes care of this stuff for you, and makes it much more convenient. There's other special modes built in too. 

Would that happen to be the 2 dimensional array cv's that you're calling special features?? Now that would be nice if NCE can access those without all the keystrokes!! Hmm..I did not know that and that's one thing that helped drive me away from using Digitrax & QSI..Hmm...Like Arte Johnson/Wolfgang used to say on Laugh-In.."Veeeery interesting"


----------



## NavyTech (Aug 2, 2008)

NCE is really hard to get for a good price. I am really not sure which one is best. It looks like if I want wireless then I have to buy receivers to go in each engine. All my engines have QSI cards in them so what do I need in order to get going in DCC with as little headache as possible.

At $530 plus a power supply to get started kinda scares me


----------



## George Schreyer (Jan 16, 2009)

That is the biggest problem with DCC. There is a large up front investment required to get much of anything going. There are cheaper DCC systems out there, but most users that stick with DCC end up with a higher end system anyway. You pay the $530 or whatever only once. If you want more locos, you just buy decoders ($55 up for large scale). If you want more throttles, you buy the throttle, it uses one RX that is mounted somewhere near trackside. If you have a very large area to cover, it might take two RX's that are widely separated, but this is usually only necessary if there is something radio reflective, like a house, in the way. 

The ProCab features notwithstanding, it is easier to program a QSI decoder (or any of them that used indexed CVs) with DecoderPro than with the throttle. DP works with any of the major DCC systems. 

You don't need a receiver for each engine, only one RX is required for the whole system as the throttles communicate with a trackside RX. The DCC command station talks to the trackside RX via wires and then transmits power and commands to the decoders in the locos via the rails. 

If you want the command flexibility of DCC without track power, THEN there is an RX in each engine that communicates directly with the decoder in that same engine. That tends to get more expensive. 

I'd like to correct some mis-information about Digitrax in the previous messages.

I ran 22 volts on the track with a Digitrax booster, I could have gone higher, but I was limited by my input voltage. The DCS200 will "hold" 8 amps, but just barely. The much older "8 amp" DCS100 will not, it craps at about 5. The older DT400r (which I have) cannot address CV's past 255, but the current production DT402 does. The older, and less expensive, Digitrax "simplex" throttles (r suffix) cannot be used to select or deselect a loco unless plugged in. The new "d" suffix duplex throttles can, but may still have some firmware difficulties. I don't have one but folks at my HO club do and they do work... and then sometimes they don't. I use an app on an iPod touch (also works on the iPhone and there is a version for Android) as a WiFi duplex throttle with the aid of an existing WiFi network and a computer running a background process. I like that throttle more than either the ProCab OR the Digitrax throttles.


----------



## SteveC (Jan 2, 2008)

Something like the following.


----------



## Greg Elmassian (Jan 3, 2008)

Jason, there is some confusion here. 

On a "normal" layout, with track power, the signal and the power is on the rails. Your locos with QSI will work right now, nothing additional needed for them. 

There is an optional board for the QSI, which makes it compatible with the Airwire system, which sends the signals over the air, not through the rails. 

All you need right now is a NCE system, and power it from your existing DC power supply. You get the command station, booster, radio base station and a radio throttle. The throttle comunicates to the base station, then the base station communicates to the command station. The command station makes the DCC signals, and the booster puts the power and the signal on the rails. 

All you need is the 10R system... 

I don't know why, but it seems that there is some information out there that is confusing the "airwire" mode of running a QSI with the traditional method of DCC via track power. 

Hope this helps. 

Regards, Greg 

p.s. Steve, the use of IR throttles, while possible with some systems, never works outdoors... I'd leave that off in subsequent diagrams, just to simplify. Also the DCC decoder itself has the speaker output... Horn/whistle is not an external device like a light bulb. The speaker is indeed an external device. The diagram is a little confusing there in my opinion.


----------



## SteveC (Jan 2, 2008)

Posted By Greg Elmassian on 29 Aug 2010 09:50 PM 
{snip...}[/i] p.s. Steve, the use of IR throttles, while possible with some systems, never works outdoors... I'd leave that off in subsequent diagrams, just to simplify. Also the DCC decoder itself has the speaker output... Horn/whistle is not an external device like a light bulb. The speaker is indeed an external device. The diagram is a little confusing there in my opinion.
Greg,

We have an 'Indoor Railways Forum' and if I'm not mistaken caferacer is currently in the process of building a rather large indoor LS layout, so I disagree with you on the point of dropping the IR, besides how hard is to say in a reply that out of doors it's best to use RF.









I changed the horn/whistle to sound.


----------



## Greg Elmassian (Jan 3, 2008)

Not hard at all Steve... of course this thread is not in the indoor forum.. I was hoping to minimize the confusion that was expressed earlier in the thread. 

I'm getting the feeling that number of choices is getting daunting. That was my drift, which I thought I mentioned. I would also not put the JMRI USB connection on a basic diagram. 

But to each his own, and if you want a diagram that shows "everything" go for it! You could add radio repeaters also, and also more boosters and power districts. 

One thing you might add is the programming track output. That can be important for certain decoders. 

Regards, Greg


----------



## SteveC (Jan 2, 2008)

Greg

The reason that I put the JMRI in was because of what George had mentioned about it being easier to program indexed (multidimensional) arrays that the QSI has.

Question, if you place a QSI/Gwire equiped locomotive on a DCC powered layout can you still control the locomotive via the Gwire/Airwire RF, and could you also control it via the track DCC?


----------



## Greg Elmassian (Jan 3, 2008)

When the Gwire receiver is active (powered / not disabled) the QSI takes commands from the receiver. Unplug it, or disable it (a switch) and it takes commands from the rails. So you could easily make a loco with a couple of switches that ran DCC from the rails, "DCC" from an Airwire throttle (track or battery power), or DC on the rails (sounds can be controlled with the $45 Quantum Engineer). 

The NCE Gardenwire throttle, which looks the same as the "normal" DCC procab can be used in the "airwire" mode the same as a CVP Airwire throttle. 

Greg


----------



## SteveC (Jan 2, 2008)

Greg

Is the following correct as far as the basics?


----------



## Greg Elmassian (Jan 3, 2008)

That's a very nice diagram. 

It's always good to note that you don't need both, battery or track power alone is fine. (right in the diagram) It's surprising how many diagrams are taken without the supporting text. 

(by the way, you might want to rename the Transceiver to "Receiver", it's not bidirectional) (Also, remove the word Magnum, Magnum refers to the QSI decoder packaged with a screw terminal adapter, not always used) 

The reason I keep stating this is the confusion I have heard lately must be stemming from somewhere, the example that you must use the QSI receiver for a "traditional" DCC setup with wireless throttles. There must be someone or something giving the wrong impression. 

I think your diagram will prove to be very helpful. 


Thanks, Greg


----------

