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Re: Question

From: Mark Willis <>
Date: Fri, 19 Jun 1998 00:54:26 -0700

Travis, you'll have a hard time doing this in the RJ-11.  All off the
top of my head, though (And I may well be wrong on polarities, etc. but
I do know a 7404 isn't appropriate in here):

  On the RJ-11 connector, there are 6 locations for pins:

  1st: usually empty
  2nd: Line 2 "Ring"
  3rd: Line 1 "Ring" terminal
  4th: Line 1 "Tip" terminal
  5th: Line 2 "Tip"
  6th: usually empty

  (I can find out which way the latch sticks out but for purposes of
your question it's all moot.)  The "Ring" and "Tip" terms refer to the
old phone switchboard days, where these were 1/4" connectors plugged in
by an operator.

  The typical on-hook (hung up) voltage Tip to Ring is about -40 to -50
volts, off-hook voltage runs more like -5 to -12 volts (varys widely),
and the RJ-11 connector goes across an audio transformer that carries
the sound as a modulated, AC signal (modulating the DC bias) carrying
the modem or voice information.  Ring is usually 100 VAC 10 Hz or so
(all this stuff VARIES, though!) but only while the phone is off-hook.

  A 7404 in this environment would be an unhappy beast indeed...

  Same in the RS-232 environment (where a +12 to -12 or +9 to -9 or so
voltage range exists.)

  What're you trying to do?  Maybe I can help.  I believe your original
plan just won't work though!

  Mark Willis, 

Travis Brady wrote:
> 
> I have a question when I hook a RJ-11 connector into the modem and in
> the phone line, what pins are recieve and send, voltage? I need to know
> so I can use a 7404 to do a bit switch on all bits coming out of the
> modem... Anyone help?

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