Hi, I am out of my knowledge zone and thought I would pose this
senario to the minds of this list for help.  I have a PIC16F877 that
outputs a pulse of 200us duration every 2ms (500Hz pulse).  I need
to send this pulse up to 350 feet down a cable.  This cable has 3
conductors that aren't twisted (have no choice but to use this
cable, more wires not an option) which are 18awg stranded.  Two of
the wires are carrying 24V dc and the 3rd wire should carry the
pulse.  The pulse is ground referenced to the positive 24V lead.  I
have 5V on the receiving PCB also referenced to the 24V positive
wire.  When looking at the pulse on the scope, it is a nice clean 5V
square pulse coming off the board.  At the other end of the cable
where it is received by another circuit board, it has a slight bit of
ringing on the 0 to 5V transition and has a lot of ringing on the 5v to
0v transition.  I had a 74HC14 on hand and put it on the receiving
PCB and connected the signal through 2 gates but it didn't help.  I
think the ringing is too great a level.  If anyone knows a good way
to get a clean signal or clean up the signal I'd be greatful for help.
I've been searching the net for info and it would seem a differential
method would be preferrable but I don't have an extra wire so its not
an option.  Thanks for any help.
Charles

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