Abstract: A system for uncovering and sealing a narrow trench. The system comprises several subsystems, including a work machine, a frame for providing a seal with the surface to be trenched, a saw blade, a vacuum system, a system for placing product, and a resealer. The blade includes rotatable tooth bits, which may be rotated and secured to create a blade for narrower or a wider trench. A removable cover and the blade are easily changeable. A surface engaging member on the frame is manipulated to maintain a seal with changing ground surfaces. Additionally, the vertical location of the blade within the frame is adjustable to create a deeper or shallower trench.

Abstract: A tuning system for a receiver of magnetic field signals. The system utilizes a stable magnetic source of known frequency, and detects a strength of the magnetic field at an antenna assembly. The strength of the magnetic field is recorded by a processor, and a control signal is adjusted to change the center frequency of the antenna assembly. Further, two or more antennas in an antenna assembly may be balanced through the same method. A variable reactance means in communication with the processor is utilized to change the center frequency of individual antennas and the antenna assembly as a whole to tune the antenna and optimize a signal to noise ratio at the receiver.