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Hi folks

I am sure this is covered and has been many times but I have not found a good way to search the forum here and have only been reading Model Railroader for decades (focused very much on HO and N) and am new to modern O gauge.

Question/problem is I have a few post war and 70's lionel, a couple MTH conventional AC third rail and a new to me Lionel Legacy engine.  I had planned on running DCC of some variety on my new layout. I have nothing in the way of controllers or transformers.  Just a 75 watt lionel from 70's and an MTH 50 watt.

I would like to run all the engines on the same track or layout but it seems like the conventional AC powered lionel and MTH locos will not do this in conjunction with the Legacy system.  From the user manual for Legacy they show something like a Lionel ZW 250 ish watt providing power but do not seem to specify that this would be the constant voltage terminals of the ZW.  It would seem that would be the set up so that there is AC power available for what I am assuming must be the Legacy decoder in the loco.

Does anyone have recommended path forward to allow the fleet I have to be used? Probably not important but planning on a mix of Ross manual and machine switches.  I also have a model railroad Dr Arduino kit but again dont see that being applied to the basic power and control scheme for engines.

It seems like the Legacy loco means that the rest of the fleet needs to have some type of decoder to be on the same layout.  Yes?  I would be willing to do this but it looks like it would cost a couple hundred a loco to upgrade given there is space and I could rewire the loco(s) motors and electronics (E unit?).  I am fine with soldering as I do this for tiny circuits at work when needed.

Is there an advantage to DCC control on the conventional AC locos that would converted to DCC by going bluerail versus the DCC being carried by the track transmission line?  Cost?  Complexity of operation?

If I use the legacy and another DCC type system (I like blue rail for example) what AC power pack would be most economical and allow running 3-4 engines. I have only had time to current draw test one of my lionel 1956 switchers for current and it looked to be about 4 amps.  Assume my mth modern locos may also pull this but I would expect their motors and certainly electronics are different so maybe not.

One more ignorant question, the 50 watt MTH tranformer that is hooked to my test track showed AC output.  I am used to DC from HO.  So these really are just transformers of voltage taking the 115v AC to about 15V AC with a reostat and current protection.  The Locos like the lionel 1956 and MTH have rectifiers to change the AC to DC for the motors?


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Welcome to O.  Just to clarify, do you just want the ability to individually run Legacy and postwar on the same track or is it your goal to run Legacy and postwar on the same track at the same time?

The latter could be challenging without upgrades.

I can run Legacy, DCS and BlueRail DCC on the same track at the same time with an AC transformer.  But in order to do that, you need to buy equipment to support each.

It would be challenging to run a conventional engine and a command control engine at the same time on the same track.  Not saying it's impossible... I've done it, but it requires a lot of user input and control.


Thanks Ron, in an ideal world both normal AC center rail or I guess what you would call conventional locos as well as the Lionel Legacy/tmcc/DCC loco on the same track.  I know that it might be possible to do this with blocks and two different controller systems but I would love not to have power blocks on the new layout.  We had power blocks with two way toggles and a control panel on our HO layout as teens in the 70's and I was so impressed with running DCC on my HO layout with my kids.

I would be willing to rewire some of the conventional (Lionel 1956, MTH early 2000's) locos to DCC but will have to look more into the options.  In addition I am guessing that my Lionel Legacy loco (EM-1) is around early 2000's before Lionel adopted NMRA standards.  I had no idea there had been this turf war in O gauge as we HO folks enjoyed total interoperability.

Any advice on setting up a power pack (like but not necessarily a ZW constant ouput) and trying to get a contoller system that is NMRA compliant?  Can I swap out the lionel tmcc decoder and get compatible with NRMA or a standard allowing me to operate without a Legacy system controller set up?  I dont want to invest in a proprietary system like Legacy if it locks me in to one vendor.  I would include the bluerail as a possiblity as this system looks well done and I love wireless technology.

Does this make sense?

Have you considered battery operation for some of the newer, easier to convert engines?

That would allow you to run to postwar stuff as they were intended to run with a transformer handle and give you the freedom to run the newer stuff right along with them.

I'll be honest, I do not know much at all about TMCC or Legacy.  We had a few LionChief upgrades which are simple and run on track power but can easily be converted to battery.

I've put BlueRail in a conventional Atlas engine, Two MTH F3 PS3 engines and a Railking 2-8-0 running in Basic mode with no sound.  The MTH engines run on battery power and the Atlas engine runs on Track Power along with the Lionchief engines.  We also have traditional DCS and Legacy (My Sons).  He has forbid me to mess with his Legacy Engine.

GunRunnerJohn here on the forum does a lot of TMCC upgrades and they seem simple enough to work with almost anything.  But then you are into the "proprietary" system.


Thanks Ron, yes I did see your video with the AEM-7 (toaster as we used to call them back when I rode the metroliner) and I think you had a video or posting where you had a battery powered (deadrail threads).  It is an interesting consideration.  I will consider it more, the thing that makes me pause, and this is probably a bit silly, is keeping the batteries recharged.  As goofy as it sounds if there were wireless charges like we have for our phones and watches now I could see parking the battery over a recharge point in the track (roundhouse if it were a perfect world) and it would be mindlessly charged for next run.  Otherwise it would mean plugging it in?  I could look up some of this on my own too so no worries.

That being said, the Lionel stuff will be its own challenge.  I will need to pursue that separately I suppose.  I had not idea that I was purchasing the tail end of a whole proprietary control system when I bid on the EM-1.  Ignorance was bliss!  I will perhaps trot over to the Lionel Legacy section of the forum and see what I can learn.  Cheers!

Can you set up a layout to run conventional, TMCC/Legacy, and DCC locomotives in 3 rail? Yes.

Can you run them all on the same track at the same time, powered via the track? No.

Some very basic ways of describing the different systems:

Conventional locomotives run just by changing the voltage to the track.  Many older locomotives have AC motors in them.

TMCC/Legacy require a constant 18V AC to the track.  The track is one half of the command transmitter antenna, the other half is your household wiring.  Locomotives have onboard antennas to receive that signal.  TMCC locomotives can have AC or DC motors.  Legacy are all DC motors. AFAIK there is only one 3 rail O Legacy locomotive with DCC on board, and is the new hybrid brass 4-4-0s.

DCC requires a constant voltage to the track, the command signal is sent along the track by modulating the voltage wave.  The locomotive can read that modulation.  They have DC motors.

You can not have conventional and TMCC locomotives on a track with a DCC signal.

You can run TMCC and Legacy locomotives on the track like conventional locomotives, as long as there is no command signal.

I do not recommend running Legacy and DCC locomotives on the same track at the same time.  Can it be done? Yes, but there are issues.  DCC tends to wash out the Legacy command signal, so the Legacy locomotives will not see it.

You should be able to convert an DC motored locomotive to DCC, I use the ESU LokSound L or XL decoders for that.  I do not know if there is a way to convert AC motored locomotives to DCC.  You can convert both AC and DC motored locomotives to TMCC.

On my layout I have no shorting switches to select between DCC and TMCC/Legacy.  Because I have a newer Lionel ZW transformer, I can control it's voltage output with the TMCC/Legacy handheld so that is how I run my conventional locomotives that are not upgraded to DCC or TMCC.

I hope this helps you some.

Thanks Sinclair

yes this is helpful.  I just read last night about Niel Young (I can just see him coming up with rust never sleeps due to cleaning his track constantly) helping to get TMCC created along with some silicon valley pals and that it radiates to antennas in the KHz frequency range.  It would appear the outside rail would comprise a loop antenna for circles of track and just a lot random antennas for more complex stuff.  Cannot imagine that it is tremendously efficient or resonant.  Or could think of it as the locomotive antenna in the (reactive) near field of the current carrying modulated TMCC outer rail.   Probably more reasonable physically.  That makes sense why DCC would interfere with TMCC radiatio as the DCC is a strong DC signal (as far as us radio frequency guys are concerned) interferes with the TMCC low frequency radiated signal.  The Digital modulation for DCC is probably not far off from the TMCC band and the track carrying the DCC radiates just as well (which is not well) as the TMCC signal.  Cool system.

It does look like to run the post war type engines I need to have power blocks or convert them the some form of TMCC or DCC but perhaps as you say best not the mix those two.


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