DCS Wiring Question

Since the DCS signal uses the wiring as a transmission line, the optimum configuration would be to run the two leads together to the track drops.  I've seen it wired in all different configurations, but for signal propagation considerations, that would be the best configuration.

JKOBRIEN,

    Guns is absolutely correct and I use high quality 14 Gauge Stranded Wire and get great results for my DCS Signal Strength.  Further Build & Test in Blocks, no more than 12 or 13 Track Joins to an individual block.  It's not the amount of Track that degrades the DCS signal, it's the actual Track Joins that due.  Use as many long Track sections as you can as you build your DCS Layout.  Use the Star wiring pattern if you can.  

PCRR/Dave

Construction continues on the Pine Creek Train Room/Bar.  Note the yellow high grade 14 Gauge Stranded Wire running from the Ceiling Track layout, to the MTH Terminal Block, and from the TIU Channel #1.  Notice also the 10 Amp Resettable Breaker Bank just to the right of one of my 2 upgraded/rechargeable DCS Hand Held Remote Controls, mounted on the 2x6 between the Z4K and the TIU.  I have 3 of these 10 Amp Resettable Breaker Banks, for all the different Transformers. Especially critical with the old Lionel ZW & KW Transformers.

Looking good Dave! Quick question, where did you get the resettable 10AMP breakers?

Pine Creek Railroad posted:

JKOBRIEN,

Further Build & Test in Blocks, no more than 12 or 13 Track Joins to an individual block.  It's not the amount of Track that degrades the DCS signal, it's the actual Track Joins that due.  Use as many long Track sections as you can as you build your DCS Layout.  Use the Star wiring pattern if you can.  

 

Hmm - that's interesting.

As an audio guy I can relate - you always want to use a 30 ft mic cord. Not two 15 ft cords - or three 10 ft cords - those introduce needless loss/failure points.

I hadn't considered this as it related to DCS signal transmission - (wiring schemes seem to be setup to overcome inconsistent power)

Alan Arnold showed me a buss system that worked well for me.   He told me to use 12 g wire but I used 10 g under the track.  I ran 14 g wire leads from the buss to the track every 5 to 6 sections of track.  Some a little closer if switches we're involved.

Some will argue that is not the right way to do it.  But look at modular RR clubs.  They do it that way and it works.

Have Fun.

Ron

Big Mike G,

   You can order them from Train Electrics LLC on the Net, mine in fact came from the original business in Florida, that Train Electrics bought out.  The 10 Amp Resettable Breakers are still available, unfortunately they discontinued building the 5 and 7 Ampers.

Roving Sign,

   Your engineering thought is right on the money, and in fact was how I stumbled across the Engineering Track Join reality.   All the wiring I had done thru the years made me take a closer look at what was really happening with the portrayed DCS signal strength, and what made it really degrade.  When I found that less Track Joins meant better DCS signal strength, I started to investigate how many actual Track Joins I could place in one block before the DCS signal was degraded.   Turned out depending on the track used, between 10 and 13 Track Joins degraded the DCS signal strength.  If you engineer using the 10 Track Join discipline the DCS signal never really degrades enough to alter any of the layout running.  I stretch it once in a while with FasTrack to 13 Track Joins but no further.  

PCRR/Dave

Thanks for the information Dave, I just tried to search them and just came up with a building electrical stuff.

Would it work to run 12 gauge from transformer to TIU and then 14 gauge to terminal block and then 18 to track or do I need a thicker gauge than 18.   A

second question is do I need to insulate the center rails between blocks if the adjacent block is powered off the same terminal block.   

Third question is if the blocks r powered by different terminal blocks/power sources do I have to insulate both power and ground rails to avoid clashing signals

thanks for the help

Greg in Wisconsin 

You can get breakers here, this company sells them in 5, 10, and 15 amp sizes,

maybe others:

https://www.amazon.com/gp/aw/d...mg?ie=UTF8&psc=1

Stackm746 posted:

Would it work to run 12 gauge from transformer to TIU and then 14 gauge to terminal block and then 18 to track or do I need a thicker gauge than 18.  

I think some people have used 18 gauge, but I wouldn't go any smaller than 16 gauge.  I think I read in Barry's book (don't have it on me at the moment), that longer runs from the TIU to a block, 14 gauge is recommended, but 16 can work.  I used 16 gauge from the TIU to the terminal block and then the same from the terminal block to the track.

A second question is do I need to insulate the center rails between blocks if the adjacent block is powered off the same terminal block.   

Yes.  If they were not insulated, they would not actually be "blocks".

Third question is if the blocks r powered by different terminal blocks/power sources do I have to insulate both power and ground rails to avoid clashing signals

No, ground is common, but you would need to make sure that the polarity is not reversed between the two insulated sections/power sources.

thanks for the help

Greg in Wisconsin 

 

 

 Hopefully this thread will not get locked since the OP was from a while ago.

Mike

My layout is wired using a #12 buss wire for each mainline with taps every 6-8 sections of traditional tubular track for the hot. Ground is done at one point on each loop. Should I run a buss/taps for the ground as well? Would doing so improve track signal?

Thanks 

John

When I do a DCS pike I run a pair of drill gun twisted non spliced 12ga or 14 ga.wires from the MTH terminal board to the end of each block.    On DCS layouts I do not use drops, instead I use bonding jumpers at each joint.  I have been told that multiple drops could present a circular path.   

The thing is, if I believe what I read, it seems like one could have many wiring variations and still get a good signal????

My layout, wired for DCS and TMCC, is divided 15 blocks. Each block has one power wire going to it. The ground is a bus loop common ground with feeders to each block section. Works perfect for both systems. 

ChooChoo1972 posted:

You can get breakers here, this company sells them in 5, 10, and 15 amp sizes,

maybe others:

https://www.amazon.com/gp/aw/d...mg?ie=UTF8&psc=1

 

I’ve looked at those on Amazon but I believe they are thermal rather than magnetic breakers, therefore are too slow to provide fast protection.

Tom Tee posted:

When I do a DCS pike I run a pair of drill gun twisted non spliced 12ga or 14 ga.wires from the MTH terminal board to the end of each block.    On DCS layouts I do not use drops, instead I use bonding jumpers at each joint.  I have been told that multiple drops could present a circular path.   

The thing is, if I believe what I read, it seems like one could have many wiring variations and still get a good signal????

The technical term is actual multi-path.  It means the signal has 2 or more simultaneous paths to get from the source of the signal (TIU) to the receiver of the signal (train on the track).  (or vice versa for the responses that go from the train to the TIU).  Multi path is bad because depending on the length of the combined wire and track for these paths, the signal may actually interfere with itself rather than there being a benefit due to the multiple drops as would be true for a pure conventional layout.

While multi path is bad, depending on lots of factors, it won't absolutely be a problem, but it could be a problem. 

I had problems years ago before understanding all of this with a simple O72 loop on my living room floor using an original TIU.  I had no blocks (it was just a single loop), so I didn't get why I could be having problems.  the lack of any gap in the center rail probably contributed to my problems since there were at least 2 paths to the train with a single drop to the track.

The TIU has improved over the years, and I've got a more recent one I use on a somewhat larger loop of FasTrack on my living room floor that works relatively well (not necessarily always 10's for track signal, but it's very rare to see errors or experience a loss of control)

-Dave

So since the blocks only insulate the power rail sending signal from TIU to engine and the side rails are not insulated between blocks that would appear to provide many paths on the common for the return signal to the TIU. So based on some of the replies the key is to have blocks of no more than 10 tracks with only one power feed and bus wiring could work for the common.   

Question.   Are there maximum recommended distances for transformer to TIU, TIU to block and block to track.    Appreciate the help.   

Greg in Wisconsin 

My sense is that for the best DCS signal, you'd have both the common and the hot lead both run from the star connection direct to the power drop.  The DCS signal is a transmission line, and dissimilar legs on the power distribution can't be a good thing.

John, did you mean "common" and hot lead?

Yep, corrected.

I am in the process of wiring a new layout (I’ll share photos of the layout at a future  date) and just want to mention that I am using #12 stranded wire and MTH terminal blocks.  I ‘inherited’ the wire from a friend who recently did an home alarm system and had this left over from his build.  I am finding that it is great to maintain voltage and the DCS signal.  In addition, while the MTH board is a bit on the expensive side, I do find it makes for a great connection point for 12 gauge wire because the connection points are wider and accommodate the larger wire size rather easily - better than the other terminal boards which I am now using for switches and accessories.  In wiring the MTH board, I do NOT place the leads to the terminal posts, rather I wire them into one of the central points on the bar - not sure if it matters but that puts the signal emitter among the leads instead of at the end.  Using that approach, I am gettting 10s at my track section some 40 to 45 wire feet away.  As an aside, although I listen to Barry Brokowitz’s advice from his book, I did not listen when he said not to have a terminal block feed into another terminal block - but doing what I said above, I am getting 10s on that long lead and all other other track sections hooked to the second terminal block.  To be fair, Barry did say a lot depends on topography and local conditions as nothing is perfect.  Because my layout is on two sides of the room and across a walkway, I actually sort of use 2 star wirings, that is one for each side, kinda explaining why terminals blocks feed into each other.  So far, so good!

Greg, in asnwer to yor question about wire size, I would not use 18 gauge anywhere in a track feed circuit.  On my large layout, it's 14-gauge from TIU to rail.

All common on my layout is bus.  Even accessories and lighting is connected to that bus.

RJR posted:

Greg, in asnwer to yor question about wire size, I would not use 18 gauge anywhere in a track feed circuit.  On my large layout, it's 14-gauge from TIU to rail.

At a distance of 5 feet, even at 10 amps, 18 gauge wire can carry all but 3.55% of the voltage to the tracks. Over short distances 18 AWG is not all that horrible. Some of you guys get spooky over wire gauge.

It is your layout. You may do as you will.  To you, I may be spooky, but I am an experienced spook.

I have a 20' by 16' U shaped layout with two terminal blocks at the base of the U, one for each of two DCS channels. I used 14 awg from transformer to TIU to terminal blocks, about 4'. 16 awg to each of 22 blocks with 18 awg drops at the center of each block gives me all 10s and 18+ volts on the track with an MRC Pure Power Dual running four engines on each of two mainlines.