Abstract: A broadband multi-bay antenna array comprising an upper antenna element group and a lower antenna element group. Each of the upper antenna group and lower antenna group comprises a pair of antenna elements separated by a distance of one-half wavelength at mid-band wavelength. Radiating elements of the first antenna in each pair are positioned in a first orientation and radiating elements of the second antenna in each pair are positioned in a second orientation which differs from the orientation of the first antenna by 180 degrees (flipped over). A center feed input port is positioned between the upper antenna element group and the lower antenna element group and is electrically coupled to each of the first, second, third and fourth antenna elements.

Abstract: An optimized coaxial transmission line having joined segments of coaxial transmission lines is provided. First insulating supports positioned at flange joints within the joined segments are provided. Second insulating supports are positioned a distance x, where x = 1 4 ? ? + n · 1 2 ? ? , from the first insulating supports to cancel reflections created by the insulating supports. Preferably, x=¼?, and the second insulating supports are positioned for one quarter of a wavelength at either FM frequencies, VHF frequencies, UHF frequencies, or IBOC frequencies. A method for optimizing a transmission line by frequency is also provided. First, segments of coaxial transmission lines are joined together, each segment having a first insulating support positioned at a flange joints within the joined segment.

Abstract: A phase shift is defined as a point in frequency at which the phase is changed from 0 degrees to 180 degrees. A device is provided for combining analog and digital in-band-on-channel (IBOC) signals to feed a common antenna utilizing phase shifting allpass filter modules to provide a 180 degree phase shift to specific IBOC channels within a constant impedance dual-hybrid circuit. The IBOC Allpass combiner includes one input 90 degree 3 dB quadrature hybrid coupler, one output 90 degree 3 dB quadrature hybrid coupler, a load resistor, and two phase shifting allpass filter modules. Each phase shifting allpass filter module is comprised of a two coaxial cavity resonators coupled to a 90 degree 3 dB quadrature hybrid coupler. Components and modules are coupled using mating transmission lines. The four coaxial cavity resonators are used as devices to produce two distinct phase shifts at isolated upper and lower IBOC side band frequencies.

Abstract: A device for anchoring one or more guy wires used to support a transmission tower is provided. The device includes an equalizer plate having a front surface and a back surface, and an anchor rod affixed proximal to a first end thereof such that a flat end surface of the first end of the anchor rod is completely exposed. The equalizer plate of the anchoring device includes a recess for receiving the first end of the anchor rod. The recess comprises a first elongated region having a width approximately equal to the diameter of the anchor rod, and an opening formed at an end of the elongated region. The flat end surface of the first end of the anchor rod preferably extends into the opening beyond the point where the opening meets the elongated region.

Abstract: A segmented transmission line used for the transfer of radio frequency energy in which the lengths of the individual segments are individually set to provide an optimally low reflection coefficient over specified frequency ranges.

Abstract: A variable coupling factor directional coupler having a variable aperture positioned between a transmission line section and a coupling conductor connected at either end to a center conductor of a pair of connectors. The coupling factor of an RF signal in the transmission line section to the coupling conductor may be adjusted by linear movement of a gap plate to open or close the aperture. Alternatively, the coupling conductor may be located within a slotted tube. As the slotted tube is rotated, the slotted portion of the tube opens or closes the aperture. The position of the inner conductor of the coupling conductor with respect to a grounded sidewall can be adjusted to change the coupled line impedance in order to optimize the coupler directivity.

Abstract: A mounting configuration for a plurality of broadcast antennas that enables location of each antenna above the top of a support structure. Antenna spacing greater than the cross section of the support structure is obtained by mounting the antennas at either end of support beams extending beyond the support structure. Controlling antenna spacing improves RF signal patterns by reducing proximity to and thereby effects of nearby antennas and or support structure. Overturning moments of the antennas are reduced by mounting the antennas to the support beams at desired positions along their length, reducing structural requirements of the antennas and the support structure. Additional support may be obtained by also securing the antennas to a lower support beam.

Abstract: A camera capable of taking a plurality of different exposures on a single frame of film using only one lens-shutter combination. A beam shifting assembly rotates to a plurality of different positions to distribute the images sequentially, thus enabling the camera to provide a plurality of different exposures on a single frame of film. Double-exposure prevention is provided both between the different images on each frame and between the different frames. The camera is provided with a "Polaroid" type back so as to enable almost simultaneous developing of the frames, once taken. The camera also includes an aiming light to facilitate proper subject positioning. In addition a strobe socket is provided for strobe energization when using low-speed film.

Abstract: A bandpass filter makes use of at least one waveguide cavity that is thermally compensated to minimize drift of a resonant frequency of the cavity with thermal expansion of cavity components. The compensation relies on deformation of the shape of at least one cavity surface in response to thermally-induced dimensional changes of the cavity. A control rod is used to limit the movement of a point on the deformed surface, while the rest of the surface moves with the thermal expansion. The control rod is made of a material having a coefficient of thermal expansion that is significantly different than that of other filter components. The rod may also be arranged to span more thermally expandable material than defines the filter such that, as the filter expands, the point of deflection is moved toward the interior of the filter beyond its original position.