[Cialug] OT: continuity test

[David Champion]

For you electronics gurus out there...

For our SCCA autocross timers, we have a set of cables that go from the 
timer head unit, to a photo sensor head out on the course (similar to a 
garage door safety sensor, bounces a light off a reflector). The cables 
have 3 conductors, we're using a fairly light gauge stranded wire, 
probably about like what's in ethernet cable. The connectors are 1/4" 
stereo headphone jack style (3 connectors). The cables may be up to 
about 250 feet in length.

Occasionally someone will get off course and run over one of the cables 
with their car, and they get some rough treatment at times, may get 
kinked, and get dragged around parking lots. I'd like to have some kind 
of way to do a quick cable test on them during setup to help shorten the 
troubleshooting time, so we'd know whether or not it's a cable issue, or 
another issue with the photo sensor.

Anyone have an idea of a simple device we could build to test the 
cables, or would we be better off using a multi-meter, or another 
pre-existing device?

-dc