At 14:49 21/09/99 +1000, you wrote:
>Dennis Plunkett wrote:
>
>> The loop to ground indicates that Paul was connected to a manual
>> exchage where a wink would be recevied, so Duplexor and privacy?
>
>  Nope, gotcha there!  It was an automatic exchange.  There were
>actually two types of relay set (called "Relay set, Duplex, type...") of
>which one required the pushbutton and one did not.  I know, because
>years later I studied (and IIRC, photocopied) the manuals for them in
>the Tech library.
>
>  The wiring in the exchange was dead easy, just two normal subscriber
>line sets with some connections wired funny.  Each connected the loop
>(was it "L") relay to one of the line wires, when this relay pulled in,
>both line wires went through that particular set and the other was
>busied.
>
>  Absolutely nothing to do with manual exchanges.
>--
>  Cheers,
>        Paul B.
>
>


AH! You are not as old as I thought!

Next thing you know, you will be telling us about the K and L relay sets,
uniselectors, first selectors and goup selectors. Slug relays and magnetic
concerntating yokes, then he will go off into why it is called tip and ring
and wink systems!

Dennis