[clug] Telephone line voltage

steve jenkin sjenkin at canb.auug.org.au
Sun Sep 5 22:27:16 MDT 2010

Francis Whittle wrote on 6/09/10 2:15 PM:
> Steve and/or Keith,  could you explain (preferably  diagram) the test
> setup you're using?  What exactly are you measuring the voltage across,
> for example?

Remove the (male) RJ-11 connector from the modem socket (leaving line
plugged into phone wall socket).

Find the two conductors in the RJ-11 with approx. 50V DC across them.
[Corresponds to '2' and '6' in a 601-type connector]

Switch multimeter scale from DC to AC...

Observe read out :-)

The RJ-11 plug has to be held in some way, because 2 hands are needed to
apply fine-point probes to the conductors and not get obstructed by the
plastic guides.

Reliable connections and repeatable measurements are possible.
[Including that sometimes the apparent AC measured goes to zero, whilst
DC is there.]

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