In message o.uk, Dave
Liquorice writes
On Sun, 23 Aug 2015 20:29:21 +0000 (UTC), N_i_c_k wrote:

But remember that BT put 1kV into the phone cable at random
intervals to discourage DIY.

That's shocking.

I can assure you the normal 50 V DC on a Direct Exchange Line
(ordinary phone line) is pretty shocking when you are up a ladder
putting on the talkback, music and control lines for an outside
broadcast in the peeing rain with you, the block and everything
soaking wet.


I had a customer with leased lines that carried audio, they were a bit
shocked one day when BT decided to phone them up. The ringing volts
were a bit LOUD apparently the monitor speaker nearly jumped off the
desk.
--
Bill
( A different one )