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I just purchased my first command control Locomotive, nothing spectacular, but a nice MTH railking PRR set.  I am about to undertake my first O gauge layout (many N scale before) using Gargraves track.  Since each outer rail is isolated from the other, is there any special wiring requirements for DCS.  I just ordered the book, but I am anxious to get started laying track.

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Barry Broskowitz, GGG, Jim Osborne and Marty Fitzhenry are MTH DCS knowledgeable. I can help to a certain extent but these are they guys that you would ask, There are more that know about DCS but these are the ones I know.

I can't remember How the layouts I have worked on are wired Jim Osborne kinda knows because he helped with the SD3R layout when they built it when DCS started hitting the scene.

Rich, I would add that you should plan on using 14-gauge stranded wire.  The local Lowes and Home Depot both carry THHC wire in a variety of colors.  I use Lowes because a Lowes credit card gives a 5% discount on everything.  I'm sure there will be a barrage of naysayers saying 16 is adequate.  Unless your layout will remain in the 8x4 category, consider that as bad advice.  Marty (mentioned above) and I agree on this; we both run multiple trains at the same time.

Thats good you are looking ahead... I wired my layout via bus style with drops every 3 ft... DCS is going to be a roll of the dice.

From what I have learned DCS is different than TMCC in that DCS suffers from "signal echo" there are many ways to eliminate this, but I will see what happens when I plug it in.

Barry, Really. 

J Daddy, that doesn't mean you have to rewire.  Simply use a Dremel and sever the center rail between each drop.  You might also ask Marty Fitzhenry for advice on how he added DCS to his old bus-wired layout, which is all perfect 10's.

I can start another brouhaha by mentioning that some experts say the black must be cleaned off the top of the Gargraves center rail and others say it need not.  Since I've been cleaning my track with Brakleen for 25 years (long before DCS), I may have taken enough off chemically.

Rich C,

   I also recommend you pick up Barry's DCS O Gauge Companion Book and the OGR Video Guide to DCS, both great educational information on building DCS/ Legacy layouts, you can purchase both, right here on the OGR forum, and with RJR close at hand definitely take advantage of his kind offer to get together, he can help you a lot with your 1st DCS layout.  

PCRR/Dave

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Last edited by Pine Creek Railroad
RJR posted:

Barry, Really. 

J Daddy, that doesn't mean you have to rewire.  Simply use a Dremel and sever the center rail between each drop.  You might also ask Marty Fitzhenry for advice on how he added DCS to his old bus-wired layout, which is all perfect 10's.

I can start another brouhaha by mentioning that some experts say the black must be cleaned off the top of the Gargraves center rail and others say it need not.  Since I've been cleaning my track with Brakleen for 25 years (long before DCS), I may have taken enough off chemically.

I have heard that, thanks. I have noticed on other people layouts that some times you can simply cut the power (hot) wire at the opposite side of the layout and remove the signal echo or degradation.

I am going to hook the system up and see what happens.

I have also noticed for some strange reason when you have both the TMCC signal and the DCS going through the rails, some areas of the layout have a weaker DCS signal? But have not confirmed.

 

 

RichC posted:

I just purchased my first command control Locomotive, nothing spectacular, but a nice MTH railking PRR set.  I am about to undertake my first O gauge layout (many N scale before) using Gargraves track.  Since each outer rail is isolated from the other, is there any special wiring requirements for DCS.  I just ordered the book, but I am anxious to get started laying track.

Yep  Join the outside rails together. Make track blocks  around 20 feet long by insulating the center rail only    with a set of feeders to each block. (hot ground).   These blocks would get hooked  up to the main control box called a TIU via a separate terminal strip depending on the size of the layout...

A simple loop  may only have 1 block .   DCS is fun but there a small learning curve. How to wire, add engine, hard keys, soft keys , right down to record playback., Lots of guys right here  just waiting to help . 

 

J Daddy,

   When you wire correctly you will have a strong signal from both the DCS & Legacy thru out your entire layout, especially now with the TIU Rev L.  Further if you would happen to have any isolated areas on your layout that have a weak signal, use the magic light in those particular areas to cure the problem.   I do like the 14 Gauge good stranded wire for my layouts, 16 is good, however I chose the 14 to further assure great signal quality.  Retro-fitting for DCS usually works out well, add the DCS and see what happens before you start to do any rewiring at all.  Use the block method with the 12 track join discipline and you DCS layout will run with all 10's thru out most of your layout.

PCRR/Dave

Dave, thanks for the kind words.

J Daddy, there seems to be consensus that no block should have more than one drop.  I have some 70 blocks, and only one has 2 drops.  Due to a bad connection through a UCS track, I temporarily put a second drop to that block about 15 years ago.  Layout builders often overlook the fact that frequent ground drops are also important.

Rich C,

   The Conventional Tubular Track works great with DCS ran it for years myself, yes you can use the fiber pins center rail, to set up your blocks, they work well.  Use lighted Lock ons in areas where your signal seems a little weak to assure max signal strength.  Definitely use the block method and 12 Track join discipline as you build.  In this manner your DCS layout will run with all 10's.   Then simply add the Legacy drop to the opposite outside rail from your DCS Track Connections, and run additional Legacy drops to the out Black Channels on your DCS TIU, both your DCS & Legacy will run with a strong signal when using this method.  Later you can thank Marty F for developing this Legacy drop method.

PCRR/Dave

Last edited by Pine Creek Railroad

Rich, you do not put fiber pins in the outside rails; only the center.  It is very important to make sure all tubular track pins are rust-free and fit snugly into both tracks.

My inclination is that 20' is too long for a block when using 10" sections of tubular track.  In sizing blocks, a key issue is whether you also want to run conventional.

Last edited by RJR

I have also noticed for some strange reason when you have both the TMCC signal and the DCS going through the rails, some areas of the layout have a weaker DCS signal?

That could be because you have a powered-up TMCC or Legacy engine in the vicinity of your DCS engine. Some, but not all, TMCC or Legacy engines can interfere with he DCS signal.

From pages 157-158 of The DCS Companion 3rd Edition:

Some, but not all, TMCC engines will degrade the DCS signal of any DCS engine with which they are in close proximity. This effect varies both by individual TMCC engine and by the distance between the TMCC and DCS engines. In many cases, an RF choke inserted in the Hot wire between the pickup rollers and the TMCC engine's circuit board will correct this problem. 

Some lighted cabooses, most notably those manufactured by Atlas O, may degrade the DCS signal, as may some engines or passenger cars with constant voltage (CV) lighting boards. Again, an RF choke inserted in the Hot wire between the pickup rollers and the circuit board in these cars will generally correct this problem. Although a number of different RF chokes may be effective in reducing interference from CV boards, one that has an electrical value of 22uh (micro henries) is known to work well. 

Lionel TMCC Direct Lockons can also degrade the DCS signal and should not be used with DCS layouts. 

There are two additional ways in which TMCC or Legacy may cause a degradation of the DCS signal. 

The first is if the “one wire” from either the TMCC Command Base or Legacy Command Base is connected to a Common wire that subsequently is connected to a TIU channel input. While there isn’t a lot of data collected in this regard, it makes sense that nothing good can come from passing the TMCC or Legacy signal through a TIU channel's DCS signal generator. 

The second is that there have been reported cases where plugging a TMCC or Legacy Command base into some surge protector power strips can cause, in addition to a degraded TMCC or Legacy signal, a degraded DCS signal, as well. Although the author has had no issues with the Legacy Command Base (or its predecessor TMCC Command Base) being plugged into a surge protector power strip, not all surge protector power strips are the same, and “your mileage may vary” from that of the author. Regardless, if a degraded DCS or TMCC/ Legacy signal is an issue, ensuring that the command base is plugged directly into a 3-prong, grounded AC wall socket is suggested.

This and a whole lot more is all in The DCS Companion 3rd Edition", available for purchase  from many fine OGR advertisers and forum sponsors, or as an eBook or a printed book at OGR’s web store!

DCS-Book-Cover-Icon.jpg

 

 

Last edited by Barry Broskowitz

Rich,

   RJR gives sage advise about the pins being snug fitting and non-rusty, take this to heart, it really does matter for a strong DCS signal, when using conventional tubular Track.  Further Barry is absolutely correct about the different Legacy Engines interfering with some DCS signals, my 37 Shannon Pittsburgh Street Car is effected by my NP Legacy Engine, especially when the over head LED fan lights are all on, I have no idea why this happens!   I also highly recommend Barry's DCS O Gauge Companion and the OGR Video Guide to DCS, the OGR Video Guide is great visual instruction by Rich Melvin, especially for the DCS beginner, purchase them both right here not the OGR forum.

PCRR/Dave

Last edited by Pine Creek Railroad

Everyone has given me sage advice and I am forever grateful.  The reason for asking about the old tubular track is I have loads of it in very good condition.  I love the looks of Gargraves and Scaletrax but if I can use the old tubular I can save a bit of coin that can be spent on the DCS system.  I am not married to any track system, so I defer to you experts on preference.  N scale was relatively easy, Unitrack or Atlas code 55.

Regarding the question of using 16 gauge wire for DCS vs. 14 gauge wire, lets discuss my layout:

  • It's 21' X 13' with an 11' X 3' extension. I consider this to be a moderately-sized layout
  • It utilizes 9 channels of 3 TIUs and has 10 AIUs. The TIUs are all Rev. L, however, the layout operated just as well with the previous TIUs that its had during its inception in 2004
  • It has 3 interconnected levels and runs DCS exclusively, although it is wired so that it can run conventionally, as well
  • It hosts 101 DCS (PS2 and PS3) engines, all on toggle-swictched sidings
  • It has 3 mainlines and 2 subway lines, one an out-and-back and the other a loop
  • It has more than 100 switch tracks, all wired for on-derailing operation, and all wired into both AIUs and control panel pushbuttons. There are 4 Routes that use all switch tracks and several Scenes
  • It has 50 or so accessories
  • It is all Gargraves Phantom Rail track with that has not had the blackening removed
  • Track power is 3 Z4000's and accessory/switch track power is 2 postwar ZWs. Lighting is powered by a pair of 25 amp DC power packs
  • All wiring is 16 gauge, stranded wire using a star/home run method
  • I have one TIU/power connection per each center rail-isolated track block
  • There is a transfer table based engine yard that is also DCS-controlled
  • Track topology is somewhat complex with 3 reversing loops built into the track plan.

The layout described above has a consistent signal strength of all 10's.

Before someone asserts that it's 'bad advice" to use 16 gauge wire, I'd very much like to hear that they have tried 16 gauge wire on a layout similar to the ones described above, and found it to be lacking in DCS signal strength.

Also, before someone asserts that a larger layout may need 14 gauge wire, I will provide two additional caveats to the above:

  • My layout has, as its longest wire run from a TIU channel to a track block, approximately 35-40 feet. A layout with longer wire runs may benefit from heavier gauge wire, however, primarily for the purpose of preventing power loss
  • Larger layouts with similar length wire runs as the mil about described above, are not necessarily a reason to use heavier gauge wire. Typically, these larger layouts may be considered to be multiple layouts of similar size, allowing for the first caveat above this one
  • Similarly, statements about removing the blackening from Gargraves/Ross track should also be considered with consideration of the above statements.

The above is my considered position as regards the choice of wire gauge for a DCS layout.

Last edited by Barry Broskowitz

Regarding the question of using 16 gauge wire for DCS vs. 18 gauge wire, lets discuss my layout:

Who suggested 18-gauge wire?

I chose 14-gauge when I built my current 37'x16' L-shaped layout in 1991 based on what was then 50 years of experience with a number of layouts, and IR drop problems, and the desire to run many conventional locos on the same handle. 

I stand by that wire choice 25 years later.  I regularly run 3 trains at a time (moving, not just powered up;with lighted passenger cars, on a single transformer "handle.", plus other trains running on different handles, with no voltage drop problems.  I normally will have over 20 DCS locos on powered-up tracks, awaiting a call to service. 

As I've said before, a layout owner can run his/her railroad as they desire.

Barry, I know you get very upset when someone doesn't agree with you, but you really didn't read what I said.

My experience with 16 gauge wire is that it results in unacceptable voltage loss.  If you have ever run conventional locos--which don't have automatic speed control--on a large layout, you'd know that unless you keep a hand on the throttle, there is a tendency to slow up in areas due to voltage drop.  In building my current layout, I was determined to avoid that.

Have you taken voltage readings with a meter on the far ends of your layout, with a few trains running on one handle/circuit, and compared them to the voltage on the output terminals of the TIU or transformer?  I have, and based on those readings, chose to use 14-gauge

Relax, Mr. B.

All, I've stated my position.  I will not make further comment on wire gauge and excite my friend from Florida. (We really are friends.)

Robert,

I know you get very upset when someone doesn't agree with you

I have no issue with disagreement. I do, however, have an issue with opinions that aren't on  topic and aren't substantiated by facts in evidence.

but you really didn't read what I said

On the contrary, I certainly did. You stated:

I'm sure there will be a barrage of naysayers saying 16 is adequate.  Unless your layout will remain in the 8x4 category, consider that as bad advice.

My layout far exceeds 8' X 4' and is perfectly happy with 16 gauge wire throughout. That makes my statements something very different from "bad advice"

My experience with 16 gauge wire is that it results in unacceptable voltage loss.

This is a DCS command control forum that we're in and we're discussing DCS layouts. Further, DCS l;cos have much less demanding power requirements and all have speed control, even when operating in conventional mode. Regardsess, your comments vis-a-vis conventional control aren't germane to a command control layout discussion.

Further, you have no data to share that illustrates that 14 gauge wire is necessary for good DCS operation. On the other hand, I have a layout, as described above, that its considerably larger than 8' X 4', and exhibits far more than acceptable DCS control and that uses 16 gauge wire exclusively. Suggesting that others emulate my successful layout is good advice.

Perhaps you should rephrase you earlier statements.

Last edited by Barry Broskowitz

Barry,

    It may have been me who started the preference for 14 Gauge Stranded Wire for running DCS, however I have no kick about using 16 Gauge either.  I purchased some real good 14 Gauge Stranded back when a company was doing a close out sale, selling it even cheaper than the 16 gauge, so I purchased a big spool of it, and it works great, the only drew back for me, is stepping it down to connect to my FasTrack layout.  I was soldering the step down, now with the advent of the TIU L, I simply use wire nuts.  Got to tell ya I have not used 16 Gauge sense going into FasTrack, years ago.  However the 16 Gauge for DCS is probably easier to work with, and in most cases is probably a lot less expensive.  The 14 Gauge does work perfectly however, and if you can get it as cheap as the 16 or cheaper, like in my case during the close out, I say use it.

PCRR/Dave

Seems like the discussion is headed in two different directions!  A simpler set of statements might be:

- DCS will work well (all 10's) on 14, 16 or 18 awg.  The amount of power the DCS puts on the track is minimal when compared to the locomotives and cars... milliwatts of signal.

- The decision to use 14, 16 or 18 is more related to the power loads and total length on each loop of track.  A big loco on a large layout with a bunch of passenger cars (or multiple trains on a single loop) would be a better match for a layout wired with 14 than with 16 or 18.  Wire has resistance per foot, so bigger wire (14 vs 18) will have less resistance and more power (volts and amps) will get to the trains on a larger layout.

- using 14 on a large layout is not done to make the DCS work better, it's done to make the trains run better.

Just my 2/100ths of a dollar....

Ed

ps. I use 16 awg on my 12'x12' layout and my 5' x 25' modular layout.  Both work well with the locos I run, and the DCS signal has no problem... I believe that 14awg is overkill for both trains and DCS, but it will do no harm if that's what floats your boat, er, makes your steam!

 

Eddie, I don't know of any DCS-proficient person who has blessed 18-gauge.

When I built my layout in 1991, I used all 14-gauge with one exception.  On the lowest level is a layover yard with 14 toggled blocks.  Running conventional at the time, and having a lot of 10-conductor 18-gauge cable, I figured I'd always have a hand on the throttle going into the area and could overcome voltage drop; saved a lot of time pulling wires and got rid of surplus.  When DCS came out, signal was lousy.  I removed the cable and pulled 14 lengths of 14-gauge.  End signal problem.

My previous layout, to which I added DCS, was wired with 18 gauge solid copper wire using the spaghetti technique.  

However, because it was blocked with one drop per track block, with insulated center rails, and had Lionel #260 lighted bumpers on all the sidings, the signal strength was 7-9.

DCS is much more tolerant of poor wiring than most folks would believe.

Last edited by Barry Broskowitz

Larger layouts should use 14 gauge stranded wire.  Tie your outside rails (ground) together.  Guys/gals, wire is cheap.  I have worked with two of the largest railroad builders Rich Roman from East Coast and SMARTT (Michael Hart) in Miami.  They build layouts the size of a High School Gym.  All grounds tied together and large wire.  They found the bigger the wire, the better the signal.  Stick with one drop to a block.   If you have a smaller layout, you can go down on wire size.  I have been involved in building many layouts and feel very lucky to have worked with the big builders.

I have seen many clubs that have home based experts that always want to do things different with little or no luck.  I learned many years ago in life to listen to the guy who has been there and done that.  

For a new guy like yourself, I strongly suggest you buy the great book that Barry Broskowitz put together.  I have a copy in my workshop and reading area in my living room.

Last edited by Marty Fitzhenry

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