Abstract: A support base fabricated with a heat exchanger for use in supporting an enna mast which contains heat generating electronic components. The base is attached to the faired mast of a submarine and the mast structure is attached to the support base. A cooling fluid is circulated through passageways within the mast adjacent to the electronic components to remove excess heat. The passageways are connected to the heat exchanger within the base. The heat exchanger consists of heat conductive exterior outer walls and an internal partition spaced inwardly from the outer wall forming a reservoir on the interior of the partition. The heated cooling fluid circulates through a serpentine passageway formed between the outer wall and the inner partition. Heat is dissipated through the outer wall into the surrounding medium. The passageway opens into the reservoir where the cooled fluid is returned to the electronic components.

Abstract: A broad passband pressure barrier arrangement is provided for insertion in circular waveguide between a source and a receiver of radio frequency (RF) energy with a spatially circumferential electric field characteristic of the TE.sub.01 mode. At least two cylindrical barrier regions are coaxially aligned and arranged symmetrically in mirror image fashion about a radial plane of the circular waveguide. The cylindrical barrier regions include at least one solid cylindrical plug region sealed in a cross-section of the circular waveguide and having a longitudinal thickness sufficient to withstand a predetermined pressure load. Each of the cylindrical barrier regions are defined by a characteristic impedance at opposing end faces thereof and a by characteristic impedance between the opposing end faces. A region-by-region impedance analysis process begins with an end face of the arrangement that is furthest from the source and is completed with an end face of the arrangement that is nearest the source.

Abstract: A broad passband pressure barrier arrangement is provided for insertion in circular waveguide between a source and a receiver of radio frequency (RF) energy with a spatially circumferential electric field characteristic of the TE.sub.01 mode. At least three abutting cylindrical barrier regions are coaxially aligned a arranged symmetrically in mirror image fashion about a radial plane of the circular waveguide. The cylindrical barrier regions include: at least one solid cylindrical plug region sealed in a cross-section of the circular waveguide and having a longitudinal thickness sufficient to withstand a predetermined pressure load, and at least one solid cylindrical tuning region having a radius less than that of the circular waveguide and further having a longitudinal thickness. Each of the cylindrical barrier regions are defined by a characteristic impedance at opposing end faces thereof and a by characteristic impedance between the opposing end faces.