DCS Block wiring

John,

Can I use short drops from the track and connect to the block wire with a 2 position strip without degrading the signal? I would like to get all the trackwork done and then hook up the TIU and main terminal blocks. Also I have a hidden storage yard with 4 tracks. Can I run that as one block with toggles for each siding if I only have one switched on at any one time?

You can try whatever wiring scheme you like. DCS is often more forgiving than one would expect regarding wiring that doesn't follow the guidelines for "best practices for DCS".

However, you minimize issues and maximize the DCS signal if you follow the generally accepted guidelines for DCS wiring. These are described in detail in The DCS O Gauge Companion 2nd Edition. I've include an excerpt from page 55 of the book that summarizes these guidelines:

In general, the highest DCS signal strength will be obtained by adhering to the following guidelines as closely as possible: 

• Attempt to limit the number of track blocks or sidings from a single TIU channel to no more than 12 - 15 

• Limit track blocks to no more than 11 or 12 track sections where sections, long or short, all count. If sections are all short, consider soldering connections between sections to make longer ones. Regardless, track blocks should not exceed 100 feet in length 

• Use 16 gauge or higher stranded wire from the TIU to the tracks. Generally, 16 gauge stranded wire is sufficient for any wire run that is 30 feet or less and is often good for longer distances. Above 50 feet, 14‘ gauge stranded wire is recommended 

• Use only high-quality, paired wire 

• Use Home Run or Star-type wiring 

• Ensure that track segments are tightly connected, and that the rails are clean and free of rust.

This and a whole lot more is all in MTH’s “The DCS O Gauge Companion 2nd Edition", available for purchase as an eBook or a printed book at MTH's web store!

Can I run that as one block with toggles for each siding if I only have one switched on at any one time?

Yes, I have many more than that, and usually leave all them switched on to charge batteries.

Thanks, Barry. Your book is right on the table as I am working.How important is twisted pair over regular 2 conductor wire and is OGR wire twisted pair? Thanks.

          John

The purpose of twisted pair is to negate the effect of any externally-induced inductive interference.  If you're using 2-copnductor wire, you could get the same effect by twisting it one turn for every 6" or so of run.

Another question is whether the capacitance effect of two conductor wire---the conductors being so close they have the effect of being a capacitor---could have an adverse effect on signal.  I leave it to gurus to argue that one.

On my layout I have neither twisted pair nor two-conductor cable.  Before DCS came out, I built my layout using several 8-conductor 18-gauge cables to feed the separate blocks in a storage yard, figuring I could overcome the voltage loss by raising the transformer lever.  When I added DCS, the signal in that area was poor, so I ripped that wire out and replaced it with separate 14-gauge wire to each block.  Problem solved.  Whether it resulted from the closeness of the conductors or the substandard 18-gauge, I know not.

John,

How important is twisted pair over regular 2 conductor wire and is OGR wire twisted pair?

The most important aspect of any wire used for DCS is that it be stranded, rather than solid. Being twisted about it's center axis is a bonus rather than a requirement.

OGR wire is twisted pair.

I used FasTrack and put a short drop on every third track.  I know it was over kill, but I had the wire and connectors.  Under the layout I used a crimp splice to extend the wire drop to a terminal block.  I connected 19 drops to one terminal block and used the last space to connect the block to the next block.  In all I have four pairs of blocks all connected together and the last one is connected to the TIU.  I'm getting 10's all the way around my one scale mile of track and both loops.  The loops have two crossover points with a gap between the two tracks.  I used #14 stranded wire and not all of them touch the red or black wire.

One more question: Would a jumper wire between sections of Fastrack underneath be equivalent or close to soldering? After that last post I can put 57 track pieces times four and hook to the TIU and go. Barry, you're right. I'll just have to see if the method I end up with works, and I'll report back. Thanks for all the help.

          John

Barry, I would ad that the wire has to be of adequate gauge.

John, the problem with soldering the tracks together, rather than using a jumper, is that over time, the joints may crack.  As the trains go over the track, it flexes slightly, and strains the soldered joint.  The jumper allows for some movement.

RJR, I just want to jumper over some places where I have 2 or 3 fitter pieces so I can have a longer block section. It's not a big deal if it is not a good practice. I just don't want to end up with something I have to do over.

         John