Abstract: One feature pertains to an acoustic attenuation device. The acoustic attenuation device comprises a fan assembly, the fan assembly including at least one fan module that directs airflow in at least one direction, wherein the at least one fan module includes a top surface and a bottom surface, a plurality of air deflectors mounted to the top surface and the bottom surface of the at least one fan module, wherein the plurality of air deflectors include a plurality of surfaces, and wherein at least one of the plurality of surfaces is an angled surface that redirects the airflow 90-degrees, and acoustic attenuating foam, wherein the acoustic attenuating foam has a two-dimensional (2-D) surface and is applied to interior surfaces of the plurality of surfaces.

Abstract: The present invention is directed to an interchangeable, modular, trailer hitch system which incorporates an LED light assembly built into the hitch assembly. The LED lighting assembly may be wired directly into the towing vehicle's backup lighting system or it may be provided with an on-off switch which may be positioned inside the tow vehicle or outside the tow vehicle near where the hitch is mounted on the vehicle. Central to the present invention is a LED light housing which mounts to the shank of the trailer ball mount. The shank is inserted through an aperture in the light housing and the light housing is rigidly connected to the shank by means of bolts which are inserted through openings in the top of the light housing and screwed into corresponding threaded bolt holes in the upper surface of the shank. Once the light housing is secured to the shank the shank can be inserted into the hitch receiver and locked in place in the standard manner.

Abstract: An AM/FM DIF radio has an IF to audio converter that provides an audio signal from an IF signal responsive to a clock signal. During the processing of the IF signal, a spurious signal is intentionally generated. The spurious signal is based on the predetermined offset which is included in the IF signal applied to an A/D converter. The predetermined offset is greater than or equal to half of the AM bandwidth and less than or equal to the system bandwidth. The spurious signal is generated at a frequency proportional to the sum of an imprecision offset and the predetermined offset. A low pass filter removes the spurious signal while preserving the desired portion of the audio signal.

Abstract: In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters (36 and 38) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism (34). In one embodiment, two or more cascaded filters (20, 24 or 22, 26 or 30,32) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.

Abstract: An AM/FM DIF radio has an IF to audio converter that provides an audio signal from an IF signal responsive to a clock signal. During the processing of the IF signal, a spurious signal is intentionally generated. The spurious signal is based on the predetermined offset which is included in the IF signal applied to an A/D converter. The predetermined offset is greater than or equal to half of the AM bandwidth and less than or equal to the system bandwidth. The spurious signal is generated at a frequency proportional to the sum of an imprecision offset and the predetermined offset. A low pass filter removes the spurious signal while preserving the desired portion of the audio signal.

Abstract: In order to protect against adjacent channel interference and the effects of weak signal in AM signal processing, pre- and post-AM demodulation filters (36 and 38) may be used where the bandwidth of both is varied in the same manner by a single controlling mechanism (34). In one embodiment, two or more cascaded filters (20, 24 or 22, 26 or 30,32) may be used for the pre- and post-demodulation filters where each of the cascaded filters has a same predetermined order and uses the same set of coefficients. In one embodiment, all cascaded filters are first order IIR filters, which reduces computation complexity. The use of a same set of coefficient for all the cascaded filters results in a same bandwidth for all filters and further reduces computation complexity. In an alternate embodiment, cascaded filters may be used for only one of the pre- and post-demodulator filters.