The term balun (pronounced bal-un) is derived from the function of the passive device that converts between a BAL anced and UNbalanced electrical signal. Common types of baluns convert 100 Ohm twisted pair (balanced) to 75 Ohm coaxial (unbalanced).
Commercial Driver License (Class A, B or C) A commercial driver license (CDL) is required for drivers of heavyweight vehicles, 26,001 lbs. or more gross vehicle weight rating (GVWR), vehicles hauling a trailer that is 10,001 lbs.
The class of the Commercial Drivers License, A, B or C refers to the weight of the vehicle. When a person gets a CDL, they take the General Knowledge test (required for any CDL) and the tests for any endorsements they want or need for that license class.