Abstract: An apparatus and method for active noise cancellation, including but not limited to, noise cancellation at VLF frequencies. The invention facilitates the reception of critical information in variable and extreme EMI scenario with no information about the signal of interest. The invention utilizes an automated, signal agnostic active noise cancellation technique and associated hardware components. In order to extract the signal of interest, vector modulation is employed to the signal from the noise only antenna so as to match it and then subtract it from the received signal containing combined noise and signal of interest. This apparatus and method ensures that a signal of interest can be extracted from an extremely noisy environment without any knowledge about the characteristics of that signal.

Abstract: A coupler has a locking mechanism which comprises a J-shaped blocking pin which is attached to a housing. A spring urges the blocking pin towards a locking arm so that a pin end traps the arm between the housing and the pin end to hold the arm in a locked position. The spring may be manually compressed to cause the pin end to move away from the arm so that the arm can swing outward to an unlocked position. The protruding pin end is bevelled and the locking arm has a bevelled portion which mates with the bevelled pin end. As the locking arm is swung to its locked position, the blocking pin end is pushed away from the arm allowing the arm to pass freely by the pin end. After the locking arm has passed over the pin end, the pin end is drawn toward the arm by the spring capturing the arm in the locked position.

Abstract: The method of flue and fireplace cleaning includes the preparatory steps, if needed, of cleaning out ashes from a pit or sump, followed by connecting a vacuum hose to a low point in each system and spraying an industrial type detergent steam spray through a steam hose from the top of the chimney downward, loosening all sooty deposits in the form of a wet slurry which is collected and removed through the vacuum hose. A fireplace is cleaned by a similar steam spray and vacuum operation after sealing the fireplace opening by means of a tight-fitting shield having openings for the steam and vacuum conduits. In flue cleaning the vacuum hose is connected by means of an adaptor having an inwardly projecting ledge which intercepts falling debris and directs it into the hose, and in industrial installations the vacuum removal system may be replaced by a removable receptacle occupying the bottom of a stack in a position to receive the debris from periodic steam cleaning operations.