Model Railway Forum

They didn’t used to be like that. Perhaps it wasn’t original BT/GPO wire.

Obviously if you have coloured wires paired with white wires they will be twisted in pairs otherwise you won’t know which white goes with what colour.

Walkingthedog wrote: ↑Mon Aug 16, 2021 2:04 pm They didn’t used to be like that. Perhaps it wasn’t original BT/GPO wire.

Obviously if you have coloured wires paired with white wires they will be twisted in pairs otherwise you won’t know which white goes with what colour.

Probably not BT original, but sold for DIY extensions etc.

Sorry if I didn't explain the colours too well. There are 4 wires in total. All wires are two coloured the first being the dominant coloured eg White/Blue is mostly white with a blue stripe and Orange/white is mostly orange with a white stripe etc.

I find it a cheap way to get single strand insulated wires, ideal for low voltage/low current projects. Though it can fracture with too much bending back and forth.

https://www.bitsbox.co.uk/index.php?mai ... ts_id=1928

I did know what you meant. They used to pair the colour with a white. There were/are basically 5 colours, blue, orange, green, brown and slate(grey).

Telephone wires, whether open wires on an open pole route or cable are always in a twisted or reconfigured formation. On pole routes with open wires the wires are transposed around each other on certain poles. In main cables they are usually twisted but if not then the circuit is moved around the cable at various locations to reduce any cross talk. Indoors its frequently not that important as the cable run is normally fairly short. But most (if not all?) internal telephone cables are made of twisted pairs.

Brian wrote: ↑Mon Aug 16, 2021 6:34 pm Telephone wires, whether open wires on an open pole route or cable are always in a twisted or reconfigured formation. On pole routes with open wires the wires are transposed around each other on certain poles. In main cables they are usually twisted but if not then the circuit is moved around the cable at various locations to reduce any cross talk. Indoors its frequently not that important as the cable run is normally fairly short. But most (if not all?) internal telephone cables are made of twisted pairs.

I am not sure about the drop wire, which is the wire from the pole to the house and usually onto the main socket. It has four conductors two for the phone connections and two spares but it also has if I remember rightly from a section I replaced, three stainless steel wires and although insulated they are not conductors but merely reinforcement for the wire. These SS wires are too springy to be twisted and as a result I do not think any other conductors are twisted. I may be wrong it was quite awhile back I replaced a section.

Richard

Frequently drop wires were a figure of 8 profile, but have altered today and two pair cable tends to be used, especially from cabinet to property. My BT (Unused) telephone cable is a twisted two pair coming in from the road to my home.

But returning to the OPs question. Twist the DCC bus pair together if desired or if they cannot be separated by around 50mm or more from other "Noisy" wiring, such as solinoid point motor wiring etc. But to date I've not experienced any problems, I have always used Bus Filters at each end of the bus pair which may help with induced spikes? On my latest layout I have lightly twisted the DCC bus pair main as it made installing the pair easier. TBH I haven't noticed any difference between the new layouts operation and the former DCC ones!