Plugging in extension causes main to ring
 

Not particularly a vintage phone question but maybe some of you experts could help me. BT Openreach have just been and installed a new master socket (NTE5?). I asked them to reconnect the cable to the extension upstairs but when I plugged in my 706 and lifted the handset, it caused the downstairs phone to ring continuously - not just tinkle. I replaced the 706 with a modern Scepter 100 (OK, relatively modern) and it did the same. Placing an ADSL filter in front of the phone made no difference. Any idea what's happening here before I get BT back?

Thanks Ken

Re: Plugging in extension causes main to ring
 

I seem to recall this happens when the A and B wires (terminals 2 and 5) are reversed in the extension socket.

Re: Plugging in extension causes main to ring
 

I know that extension wiring faults can cause this, but I've only ever known it happen with phones that have electronic tone ringers rather than electro-magnetic bells. The latter require 25Hz AC to operate them and as far as I know this will only be present when an incoming call is awaiting answer.

Re: Plugging in extension causes main to ring
 

I haven't tried a different phone on the main socket yet - the one that rings is an electronic ringer.

Ken

Re: Plugging in extension causes main to ring
 

I was confused because you said it was a continuous ring and not just a tinkle. Tinkle to me means a magneto bell.

Re: Plugging in extension causes main to ring
 

Pretty sure it happens when there's a reversal of wire 2 and 5 at the telephone with the electronic ringer.

When you lift the handset of the 706 (or 746), the 12V d.c. passes from wire 5 through T18 and 19, one set of switch-hook contacts, the ASTIC, the regulator, the other set of switch contacts and out through Terminals 4,5,6 to Terminal 3 in the master LJU thence to wire 3 of the extension telephone cable.

But if the bottom of the electronic ringer is connected to wire 2 instead of wire 5. there'll be a direct current through it and it will hoot.

Re: Plugging in extension causes main to ring
 

Yes, I should not of written tinkle for an electronic ringer, sorry about that.

Russell, sound like a very good description of the problem, I'll check the wiring.

Thanks both for the advice.
Ken

Re: Plugging in extension causes main to ring
 

If it helps on the feeling, I have had some tinkle like sounds on the oldest electronic ringer I have, in that hence that when an other rotary phone is used it comes a weak beep for each pulse. :-)

Re: Plugging in extension causes main to ring
 

That's minor, our cordless 'phones ring for another cycle even after the other party has answered it.

Re: Plugging in extension causes main to ring
 

Yes, our Panasonic cordless does that: one of the newer generation of 'two-wire' telephones.

Mrs B. likes that one and it's handy for DTMF but it sits next to my current living room telephone (a 1960 type 710), and it's annoying when I answer the 710 and the cordless is still bonging away.

Re: Plugging in extension causes main to ring
 

I'm still rather confused regarding my original question so I've attached a photo of the new master socket wiring and the hall extension, which has not been changed. Does it look right? (sorry about the poor photography)

By the way, our BT Sonus cordless also keeps chirping for a while after the call has been answered on the 706!

Ken

Re: Plugging in extension causes main to ring
 

Wiring is wrong.

Blue/white to 2, White/blue to 5, Orange/white to 3.

Re: Plugging in extension causes main to ring
 

Blue/White on 2 and White/Blue to 5 as above.

Orange/White should be on 3 on extension sockets.

White/Orange & Green/White & White/Green are not used on residential setups.

See [URL="https://britishtelephones.com/wiring/socketwiring.htm"][URL="https://britishtelephones.com/wiring/socketwiring.htm"][/URL for more info.

Re: Plugging in extension causes main to ring
 

Looks like white/blue spot in the first picture is not connected by the time it gets to the extension ..you have blue/white spot connected instead

Re: Plugging in extension causes main to ring
 

Well it seems whoever originally wired the extensions up when the house was built used a different colour code but at least it worked. With the new master socket the BT engineer did it properly. I have now rewired both extensions, but I cannot test it yet as the line has gone dead - due, I hope, to the old number being transferred to the new line.

Thanks for all the advice, I also found this URL helpful: https://www.tlc-direct.co.uk/Technic...e%20Wiring.htm

Re: Plugging in extension causes main to ring
 

Just for info - it's an NTE5C, which has superseded the 5A in recent years.

Re: Plugging in extension causes main to ring
 

OK thanks. Has MK 4 on the cover too.

Re: Plugging in extension causes main to ring
 

It's a good job you didn't get BT back, might have been expensive!

Re: Plugging in extension causes main to ring
 

Right! Well the number transfer has completed and we have the line working again. The extensions now work properly, and interestingly, pulse dialing still works. As it is now a Plusnet FTTC line that surprised me.

Re: Plugging in extension causes main to ring
 

I'm glad it's all sorted now - and wired to BT conventions, which should cause less confusion in the future.