Abstract: A layered directional coupler including conductive traces placed along predetermined axes for making contact with main and auxiliary signal lines. The axes are positioned at predetermined angles relative to each other to maximize the area for making contact thereto, which minimizes the size of the directional coupler. Ground planes are used to minimize parasitic coupling between the traces. The main and auxiliary signal lines are provided by inductively coupled juxtapositioned spiral coils which coupling maximize the characteristics of the coupler.

Abstract: A layered directional coupler including conductive traces placed along predetermined axes for making contact with main and auxiliary signal lines. The axes are positioned at predetermined angles relative to each other to maximize the area for making contact thereto, which minimizes the size of the directional coupler. Ground planes are used to minimize parasitic coupling between the traces. The main and auxiliary signal lines are provided by inductively coupled juxtapositioned spiral coils which coupling maximize the characteristics of the coupler.

Abstract: An improved squelch circuit which utilizes a phase-locked-loop (PLL) arrangement to track the carrier signal and identify when audio communication should be curtailed. The lock detect circuit of the PLL is used for a signal-to-noise monitor. As the loop locks and unlocks, the lock detect line pulses. These pulses are integrated to give a direct current (DC) level. This DC level is proportional to the signal-to-noise ratio of the carrier signal. The signal-to-noise level is monitored by the squelch gate until a threshold is passed. Falling below the threshold results in a squelching of the audio, when the ratio exceeds the threshold, then audio is commenced. The circuit is enhanced by the ability to automatically adjust the threshold level once the PLL has locked onto the signal.

Abstract: Apparatus for monitoring the status of and controlling faults at remotely-located components in a single line communications system wherein return data signals from the components are transmitted in the 50 kHz to 200 kHz range, and coupled to the low pass filters commonly used to bypass the active components, thereby permitting the return of signals to the system head-end.

Abstract: An audio signal to color pattern display signal converter-modulator includes an input audio signal section, four frequency band filters, horizontal sync and sweep circuitry, vertical sync and sweep circuitry, a pulse width modulator section, a level converter-modulator matrix, a chroma encoder circuit section and a chroma and luminance modulator and video output circuit section. The pulse width modulator section includes a CMOS NAND gate associated with each of the four frequency band filters, each NAND gate and each filter combination corresponding to a different primary display color. Each NAND gate has one input coupled to an output voltage signal from its corresponding filter section and the other NAND gate input is coupled to a sine wave signal. There are four such sine wave signals each sequentially phase shifted by 90.degree. from the preceding adjacent sine wave.

Abstract: Certain halogenated aromatic polyester fibers having reduced spin-line static generation when prepared via dry-spinning from a methylene chloride containing solution are provided by admixing an esterified hindered phenol prior to dry-spinning. A preferred esterified hindered phenol which may be utilized to reduce spin-line static is tetrakis[methylene 3-(3',5'-di-t-butyl-4-hydroxyphenyl) propionate] methane.