[Tfug] Yet another poser

[jblais]

> -----Original Message-----
> From: tfug-bounces at tfug.org [mailto:tfug-bounces at tfug.org]On Behalf Of
> George Cohn
> Sent: Wednesday, September 26, 2007 8:16 PM
> To: Tucson Free Unix Group
> Subject: Re: [Tfug] Yet another poser
>
>
>
> X10 is a carrier current system, the signal is superimposed on the A/C
> power line.  If you go to http://www.X10.com you might be able to find
> the specs.  I use X10 throughout my house, been using it since BSR
> originally developed the first commercial product.


Yes, I have some too. But that's what I mean, signal and power on the same
pair.  Isn't that what the POE may be doing?

>
> Telecom is different.  The single pair, green = tip, red = ring, was not
> grounded.  However, they did go through a lightning arrestor and it did
> have a ground wire.  Sometimes they use white = green and blue = red.
>

Perhaps it was an arrestor!!! But cleaning the wires fixed the problem !


> BTW, the positive or red side is signal ground at the central office.
> Conceivably they could have used just one wire but it potentially would
> be very noisy due to the resistance of "ground" at the customer premise.
>
> The terms tip and ring come from the old cord board days when the
> operator had to plug in a patch cord to connect parties.  The cord
> actually had three contacts, tip on the very end, ring was next, then
> sleeve was closest to the cord.

I almost got a an old 30-line "shelf", but the AT&T guy ended up with it!

>
> In the old days of party lines, IE more than one subscriber on a pair,
> they often used various methods for the bell.  On one party it might be
> connected to tip and ground, on another ring and ground, on a third it
> might be bridged across tip and ring, and they even used harmonic
> ringers that responded to different frequencies for 4 to 8 party lines.
>

Yes, we'd pick up the phone and listen if someone was already talking,
before we could call.  I forget what our ring was, something like 2 longs
and a short.  I forget if the phone had a dial or not, we may just have
clicked the receiver to get the operator.

> Imagine trying to do dial-up on an 8 party line!  ;-)
>
> George Cohn
>
>