kanawha posted:... In all cases the green light flashed, never got the red light to flash.
When you say "the green light flashed," you do mean both green & red simultaneously? You should never be able to make JUST the green light to flash (by itself).
OTOH, if the signal is in the "maybe" zone (5-10V) then you can get JUST the red to flash.
There is no published info from MTH that specifies the minimum DCS signal level fresh out of the box. Anecdotally, based on Adrian's extensive study (refer to other OGR threads where he shows tables, oscilloscope photos, etc.), new TIUs indeed put out more than 10V. So, in practice, if you have a "known good" TIU and adjust the trimpot to flash green (and red) when there is DCS activity, then you will be setting the threshold higher than 10V. My guess is the change in trimpot "angle" between 10V and, say, 12V will be small...maybe only 10-20 degrees?
Remember, the screw-driver calibration technique is just to get you a seat at the table - no oscilloscope required.
