A manhole collar for mounting in a manhole is defined by a tube with rigid strips shaped to form lobes welded around the upper edge with a bottom edge of each lobe for engaging the ground or other surface around the manhole. A signal evaluator determines or measures a signal quality level associated with the received electromagnetic signal. A connection element with a socket housing is arranged at each of the first end and the free end of the piston rod for receiving a ball head. The method also includes dynamically decreasing a frequency of the clock signal to decrease a dropout voltage of the switching regulator. In a preferred embodiment, a dual fuel engine operates using diesel as a first fuel and natural gas as a second fuel.