A USB plugs inline with your USB cable. Useless for anything else. But checking USB with a conventional meter is not fun. You need both types plus a wall meter for the rig battery and another meter for AC voltage. Sounds intimidating but today's prices are reasonable for all.I prefer handheld meters with lots of manual settings on the dial. Chinese fool engineers love to make mv, ohm and other symbols #1 font on the LCD panel so a microscope is needed to see what range an autorange hand held meter has chosen. With manual there is no ambiguity.
