How is TMCC different from DCC in smaller gauges??

[gvdobler]

Using DCC In the smaller gauges there is a decoder installed to receive commands from the cab (handheld or tethered.)

You do not refer to it as DCC in O, why is that.

Does MTH only run MTH and Lionel run various other brands?

If you buy TMCC can you buy decoders and install in non equipped locos?

Sorry for all the questions. I was in a Lionel only store and did not get a very good answer. The TMCC was very nice, operating on Fast Trax in the store.

Thanks for any advice.

[Big_Boy_4005]

Actually DCC is available in O scale, but it is most common in 2 rail, though it may well work on 3 rail too. I have always thought that it had to do with the fact that 3 rail uses an AC track power environment.

I'm not sure about how the actual signal is created in the different systems, but the transmission methods are quite different . The track power environment may have something to do with this.

DCC sends its entire signal through the rails.

TMCC's signal uses "thin air" as one pole of it's signal. Each receiver has an "antenna" which looks for an earth ground. It is possible to get some reception problems when trains are unable to locate a good ground source. This usually happens when the track is shielded from above, like under bridges or inside tunnels.

DCC has different problems, often due to bad contact with the rails in a 2 rail environment. Bridges and tunnels are not an issue.

One other major difference is how the throttles communicate with the command bases. TMCC is again through the air. Most DCC throttles are plug in, though wireless models are now on the market, they aren't standard.

When it comes to MTH, I'm not familiar with that system, except to say that DCS can control TMCC engines through a slave arrangement using a command base and a TIU. TMCC cannot control DCS, and both signals are so different, that they can be used together on the same track without interference.

My understanding is that DCS can control DCC also, but I have no idea how that works.

All of this command control stuff is very cool, but also very mysterious if you aren't an electronics wizard with an oscillascope.

[lionelsoni]

DCC uses a voltage of constant magnitude whose polarity is reversed frequently in a pattern that encodes the information being sent to the trains. See
http://www.dcc.info/standards_rps/

[Bob Keller]

There was a group called 3rdRDCC that was working to develop a DCC program for 3rd rail operation. I know they set up at a few major shows to try and generate interest, but I don't think anything is happening on that front (and the last thing the three-rail market needs is yet another control system). Their FAQ does discuss some of the issues.

Their website is http://www.3rdcc.com/faq.html

The home page has a "Breaking News" update dated Sept 1, 2001.

[Anonymous]

QUOTE: Originally posted by gvdobler

Using DCC In the smaller gauges there is a decoder installed to receive commands from the cab (handheld or tethered.)

You do not refer to it as DCC in O, why is that.

Does MTH only run MTH and Lionel run various other brands?

If you buy TMCC can you buy decoders and install in non equipped locos?

Sorry for all the questions. I was in a Lionel only store and did not get a very good answer. The TMCC was very nice, operating on Fast Trax in the store.

Thanks for any advice.

Yes, most new engines in the smaller gauges come with standard NMRA sockets which allow the operater to plug in a great variety of decoders with a great range of capabilities and prices. Or they come with decoders already in place.

We don't refer to DCC in O gauge because it's very rare. For better or worse, TMCC (Lionel and others) and DCS (MTH only) are by far the most popular control systems in O gauge.

One can add a DCS system to an existing TMCC system and control (with some limitations) TMCC engines from the DCS remote. TMCC can not control DCS engines. (In command mode.)

You can buy TMCC conversions for as little as $65 and pretty easily add them to neary any piece of O or 027 equipment made since the beginning of time. Now you can buy DCS PS2 conversions for $180 and have someone add them to a limited number of modern equipment for an additional $80-150. It may be possible to do a DCS conversion youself but due to the complexity of the conversion, it is NOT recommended. For that price DCS includes much, much more functionality. To effectivly equal the functionality of DCS with TMCC, the TMCC decoder will run about $230. But with TMCC there are many more options available from several manufacturers in between the $65 and $230 levels.

The one thing that almost everyone agrees on, from toy train nuts to scale model railroaders is that command control (be it from Lionel, DCS, or even DCC) is a very enjoyable way to run trains. The proliforation of control systems is annother matter.

If I started over again with what I know now, I'd go DC power with DCC control. Yes, even with 3 rails. Don't let anyone tell you it can't be done. But you can't buy the 3 rail equipment "DCC Ready" right out of the box ready to go.

Enjoy your trains, man. That's the important thing.[:)]

[palallin]

FWIW, TMCC is making inroads into 2-rail O. The AC isn't a problem: the receivers include bridge rectifiers for the DC motors, just as in 3-rail.

[nblum]

The major technical difference is that TMCC is independent of the power (voltage)provided to the track. This is a major technical advantage of TMCC over
DCC and DCS, in terms of cost, simplicity and, in some instances freedom from
interference and in all instances with larger layouts, ease of wiring. You can provide
power as cheaply and exactly as you like, with no blocks you don't need with TMCC.
In DCC (and DCS) the signal is part of the power system, and thus subject to
more complex wiring, blocks, and, in the case of DCS, more subject to the geometry
of the wiring, trackage, inductances, etc.

DCC is much more expensive to implement than TMCC in terms of the controlling equipment, particularly if you want wireless remote control. DCC is standardized so that any DCC decoder equipped loco will respond to any DCC setup. TMCC requires
TMCC receivers inthe loco and will not control DCC or PS2 (DCS) locos in command mode. TMCC electronics are available for as little as $50 per loco from three major sources (Train America Studios, Digital Dynamics and the Electric RR Co.).

[Anonymous]

QUOTE: Originally posted by nblum

TMCC electronics are available for as little as $50 per loco from three major sources (Train America Studios, Digital Dynamics and the Electric RR Co.).

Neil, you must have a cupon or somethin' because the cheapest upgrades I can find from DD is the $65 motor mite (the only one available in that price range that is advertised for AC motors), from TA the Beep board is $69.95, and ER beep upgarde is $69.95. The $50 LCRUs from DD are long gone. (All info per the various websites.) You can do a mini driver board from Carl Tuveson for $25 and buy a R2LC for annother $29.95, but that's $55 and shipping from the two different suppliers will pretty much eat up the difference... Please tell me if I'm wrong, 'cause I'd love a $50 upgrade.

[nblum]

You're right, I was thinking of the AC/DC Commander from the Electric Train Co., but I forgot that doesn't include the R2LC.

The Beep Commander is about $70, which is still a pretty good deal. I don't know of any AC or DC high current DCC receivers that cost less, but I haven't looked extensively.

http://www.electricrr.com/

[nblum]

That having been said, three rail O gauge high current DCC receivers with sound capability will no doubt cost as much or much more than TMCC setups now available.

[Anonymous]

QUOTE: Originally posted by nblum

That having been said, three rail O gauge high current DCC receivers with sound capability will no doubt cost as much or much more than TMCC setups now available.

I wouldn't be too sure of that - basic NCE 4/8 amp decoders are $67 at Tonys so it's basicly the same. The new generation of sound decoders will have scalable/programmable cruise control included! To get a comparable TMCC upgrade you need a full EOB/RS 4.0 set up from TA @ $230 which will probably be more than the DCC. Or a PS2 upgrade. And it's still not scalable/programable.

When the next generation of sound DCC gets here (like the Soundtraxx Tsunami), look out. Because there's stuff in there that even DCS doesn't have, like built-in adjustable sound frequncy EQ and reverb. Turn up the bass! Or not, depending on you speaker set up. How about 2048 speed steps? How about exhaust note based on actual load not just speed?

The old O gauge arguments against DCC are wearing thinner every day. Every time one O gauge company sues the other one over technology it gets scarier for those who have invested in those technologies on their layouts.

Old 2037

[nblum]

Even the inexpensive boards from the Electric RR Company have up to 128 speed steps I believe, which is more than enough for most of us, maybe too many. Command plus cruise plus sound for not much more than $100 per loco, no? It's sound where the DCC expense is going to outstrip the cost of TMCC is my guess. But time will tell. O gauge three rail is way ahead of DCC in terms of sound quality and availability at this point. As you say, that could change. If things deteriorate in three rail, DCC may become more attractive, particularly if we wind up with one proprietary manufacturer or something lousy like that :).

[Big_Boy_4005]

Yes, but hasn't the big gripe been that the technology that was to be included in the Tsunami is locked up in the MTH patent? Who knows when the Tsunami will come out if it has to be redesigned.

One minor detail, with regard to large layouts. While it is not necessary to break up the track into blocks for control purposes, some amount of segmentation is a good idea for current limiting and power distribution.

Please correct me if I'm wrong, but doesn't the actual TMCC signal reach the engine via the wheels? My understanding is that the signal gets it's strength from the antenna being able to couple to a source of earth ground. This is why metal objects interfere with reception. If you apply an earth ground to those objects, or locate an alternate source near them, the problems tend to clear up.

If the signal was really going through the air, wouldn't it be easier to amplify it and just broadcast it ?(if it complied with FCC regulations)

[Anonymous]

"Command plus cruise plus sound for not much more than $100 per loco, no?"

No, I don't think so - I may be wrong but I don't think you're getting cruise with a $100 command upgrade. You're getting a 4 amp control with the 100 steps, and some sound, but not cruise. (If it does include cruise they really should re-write the web copy and the operators manual -nether of which mentions any cruise control capability.)
I'm pretty sure the basic TMCC upgrade with real cruise is TAS EOB, which starts at $154 with no sound at all. With RS 4.0, try $230. The DCC boards with sound and cruise are gonna be cheaper than that. All by themselves, RS4.0 upgrades are $90. I think DCC sound is gonna be cheaper, if anything. They can spread the development costs over a lot more product - from Z to G!

[Anonymous]

"Please correct me if I'm wrong, but doesn't the actual TMCC signal reach the engine via the wheels?"

Nope. The track is the broadcast antenna and the receiver antenna is a wire inside a plastic engine, or an insulated handrail on a die cast one.

It remains to be seen wether the Tsunami actually infringes on any MTH patents - the mere vague threat of a lawsuit was enough to delay it to be sure it doesn't. This is why MTH hasn't exactly been received with open arms in the HO community. Many in that community have alleged that that threat was simply an anti-competitive tactic. I have no knowledge one way or the other - but also I would not jump to the conclusion that any technology in the Tsunami was "locked up" by any MTH patent or that Soundtraxx was infringing just because it's been delayed. As I remember DCS had a few delays along the way....

Old 2037

[Anonymous]

It my understanding The DCC in HO is copatible between manufactures. In O every brand is different and even old MTH stuff will not work with the newer systems. The manufacturers have done the O gauge hobby great harm for their own greedy behavior and they all can go under as far as I am concerned.

I am sticking with postwar.

Charlie