How many Phones on one line

[DIYspanner]

If the cable was sub-standard and the pairs of wires were not twisted as they should be, would that cause issues ?

 

[bernardgreen]

Why have the colours been changed from what BT have been using over the years ?

On some installations of internal extension wiring (post-2012) BT/Openreach have now come full circle and have reverted back to using white four core cable containing solid colours: blue to pin 2, orange to pin 5, brown to pin 3 and green to pin 4 (if used).

So that cable from ebay may be to spec CW1308

 

[PBC_1966]

Interesting, I hadn't realized they'd reverted to the older coding (not been following recent changes too much since I left the U.K.). Is it really 2-pair as per that eBay listing, or just plain quad like the old P.O. cable though?

But either way:

If the cable was sub-standard and the pairs of wires were not twisted as they should be, would that cause issues ?

No, whether it's twisted pairs or not it wouldn't result in your problem. As mentioned already, the older internal cable (installed up to circa 1980 or 1981) was plain quad, not twisted pairs.

 

[DIYspanner]

What about the insulation on the wires if its not thick enough so being a substandard cable ?

I've have phone no.3 unplugged for over a week with no issues.

A long story but phones no. 1 and no.2 are connected with cable a few years old and no.3, cabled from no.2 has cable that is 15 years old and perhaps that length is substandard and worth replacing.

New socket plate (Selectric brand) and new phone at no.3 point!

 

[bernardgreen]

As mentioned already, the older internal cable (installed up to circa 1980 or 1981) was plain quad, not twisted pairs.

I have never known GPO, BT, OpenReach or any other telephone service provider use anything but twisted pair, albeit a very low number of twists per yard ( metre ) but always twisted. Where there was more than on circuit on the route open wire circuits were "twisted" by crossing the conductors over every few hundred yards.

What about the insulation on the wires if its not thick enough so being a substandard cable ?

No a few microns of insulation would be OK

 

[DIYspanner]

I'll test the cable for continuity with an ohm meter and a mate has suggested using his insulation resistance tester.

In my opinion it can only be the cables.


ref: Ringer Equivalence Number mentioned above.

As far as I can see, the extension socket plate only has mechanical contacts so how does the REN standard apply ?

 

[bernardgreen]

socket plate only has mechanical contacts so how does the REN standard apply

because if there are too many "bells" or rngers on the line then the AC ringng current will be too high and the exchange may see this high AC current as indicationg the phone has been lifted. ( answered ) so the exchange then turns off the ringing current.

I already explained this in my first reply to you,

 

[Nozzle]

There was a time when only approved BT equipment should be connected to your phone line, presumably to sustain performance of your phone and others on the exchange. Now when one can buy a phone from almost anywhere, that is likely built in China to a small cost, there's not the assurance of quality there once was. Do any of the phones you have connected fall into this category? It doesn't have to be the most recently connected one that is causing the problem, just the straw that broke the camel's back. Clearly the BT Duet model should be to spec, but I can't tell the brand of the other photo

Nozzle

 

[DIYspanner]

Now I understand REN, I've checked the BT Duet and its REN1.

The Binatone (model no. 1312) at socket 1, doesn't have an REN rating marked on it but the wireless handset that came with it isn't used. The phone actually uses a DC supply lead for its memories.

The phone at Socket 3 is an Optimum brand, purchased at B&M and was made in China. Again, no REN marked on it.

http://www.bmstores.co.uk/products/slimline-corded-phone-257026