Jul 17, 2015 - 04:42 PM
This is because the MODIS uses a shared ground for all 4 channels.
The yellow lead included with the AES ST3 Test Drive Test Lead Set has a ground permanently attached to it. We assumed that most techs would use the yellow channel 1 when viewing only one signal.
Based on this assumption, and for maximum flexibility, we have included removeable ground pigtails for the other leads in the set in case you don't want to use the yellow lead. The ground pigtails plug into the "junction block" on the blue, green, and red leads.