Continuous or end to end?

At last, track laying has started at Ottersford, which will be a 'roundy roundy'.  I'm putting in the BUS for the power feed, & to my simple mind a continuous loop of two wires with the feed from the transformer linked in will give a better power stability over the 15 m run.  However, the more I find out about DCC wiring I realise how little I know, & maybe the BUS should run from the power supply 15 m around the layout & end in a terminator?  Or should it go from the power supply in a 'T' formation, 7.5 m each way both ending in terminators?

Grateful for any advice - starting to see the attractions of clockwork!

Mal

Hi Mal

My layout is 22 feet by 12 feet 'roundy roundy' with four track plus an 18 road fiddle yard. I operate it with a continuous loop BUS and experience no problems whatsoever. Also contains a six road engine shed - see photos in the Gallery.

Derek

Mal, unless you have an 8x4 ft layout, it is recommended not to run the DCC power bus in a loop, but dead end them in the terminators. Ideally the command station/power unit would be centrally located so the arms are approx 50/50. similarly the track rails are not in an electrical loop either, use insulated fishplates. For terminators -see http://www.members.optusnet.com.au/nswmn2/DCC.htm#Terminators

Mal, one reason why it is not recommended for a large loop is signal timing. If a loco is right next to the command station, it gets the digital signal from two directions, close by the command station & the second from going all the way around the layout so the decoder can get two identical commands, one a fraction in time behind the other and may cause confusion. There may also frequency considerations as the DCC power is high frequency.

Cheers guys, I knew there would be something obvious I hadn't thought of.  Those little messages whizzing round both ways & getting everything confused - who'd have thought?  So a 'T' it'll be.  Pouring with rain here today so a good day to be under the layout - if there ever is a good day for that.  Thanks again.  Mal