A few more DCC questions please.

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The Sligo Rover
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A few more DCC questions please.

#1

Post by The Sligo Rover » Sat Mar 14, 2020 8:14 pm

1/ Is it imperative to twist the DCC bus cables? I have read something like 8 twists to the foot.
2/ Can I have two bus circuits on a layout? In my case it would appear easier to run two circuits rather than have one great big long one going all around the layout. Does it make fault finding easier?
The two circuits would be from the same controller, just split within about 18 inches of the controller.
3/ Does it matter if I have a soldered join or two in the bus wires?
Apologies if these points have already been covered, sometimes it is a job finding them.
Thank you again from a novice who is just about ready to start cabling tomorrow depending on what the recommendations here are.

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Brian
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Re: A few more DCC questions please.

#2

Post by Brian » Sat Mar 14, 2020 8:36 pm

The Sligo Rover wrote:
Sat Mar 14, 2020 8:14 pm
1/ Is it imperative to twist the DCC bus cables? I have read something like 8 twists to the foot.
2/ Can I have two bus circuits on a layout? In my case it would appear easier to run two circuits rather than have one great big long one going all around the layout. Does it make fault finding easier?
The two circuits would be from the same controller, just split within about 18 inches of the controller.
3/ Does it matter if I have a soldered join or two in the bus wires?
Apologies if these points have already been covered, sometimes it is a job finding them.
Thank you again from a novice who is just about ready to start cabling tomorrow depending on what the recommendations here are.
Hi
Try and answer each in turn..
1) No but it helps on longer bus wire runs where inducted interference may then become a problem.
2) Of course not, but I cant see any advantage of one pair extended or two pairs!
3) Best practice is to always solder all joints whether in-line or tap offs for droppers

Hope this helps?
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The Sligo Rover
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Re: A few more DCC questions please.

#3

Post by The Sligo Rover » Sat Mar 14, 2020 8:54 pm

Thank you, what distance would you class as a ‘longer bus wire run’ please?

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Brian
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Re: A few more DCC questions please.

#4

Post by Brian » Sat Mar 14, 2020 10:36 pm

Over 4 Mtrs
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The Sligo Rover
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Re: A few more DCC questions please.

#5

Post by The Sligo Rover » Sat Mar 14, 2020 11:34 pm

Thank you again, I need to start twisting on your recommendation.

Forfarian
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Re: A few more DCC questions please.

#6

Post by Forfarian » Sun Mar 15, 2020 9:15 pm

Brian wrote:
Sat Mar 14, 2020 10:36 pm
Over 4 Mtrs
My bus is about 9 mtrs in a U shape, but the main bus wires are about 30cm apart in separate holes through the base board, with loops to choc box connectors as required.
Never gave any problems.
Would being spaced out make a difference Brian?
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RAF96
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Re: A few more DCC questions please.

#7

Post by RAF96 » Sun Mar 15, 2020 9:52 pm

Have a look at this Noddy guide to transmission bus wire effects
https://www.youtube.com/watch?v=ozeYaikI11g
The video #143 immediately following is of more practical use though.

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Brian
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Re: A few more DCC questions please.

#8

Post by Brian » Mon Mar 16, 2020 9:57 am

Forfarian wrote:
Sun Mar 15, 2020 9:15 pm
Brian wrote:
Sat Mar 14, 2020 10:36 pm
Over 4 Mtrs
My bus is about 9 mtrs in a U shape, but the main bus wires are about 30cm apart in separate holes through the base board, with loops to choc box connectors as required.
Never gave any problems.
Would being spaced out make a difference Brian?
Yes, spacing long wire run bus pairs apart - more than roughly 2 1/2" inches and a greater distance would be better, this will reduce the risk as too will twisting the bus pair.
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