Abstract: The output voltages produced by two directional couplers are applied to analog circuitry for generating a voltage that is directly proportional to return loss. An analog meter scale is calibrated to indicate return loss in decibel units and/or voltage standing wave ratio (VSWR) directly.

Abstract: A typical pinhole leak that has occurred along the flue pipe of a water heater is quickly and effectively repaired by employing a spring-tempered, sealant-coated cylindrical repair section that is first coaxially positioned inside the flue pipe in a compressed position and that is subsequently triggerably released to spring to an expanded position whereby a permanent sealant layer is formed between the cylindrical repair section and the flue pipe.

Abstract: An adaptable programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user, an LSI NMOS central processing unit, and an LSI NMOS peripheral interface adaptor capable of bidirectionally transferring information between the read-write memory and central processing unit and a number of input/output units. The modular read-write memory includes a movable boundary between a program storage section thereof and a data storage section thereof to permit the user to adjust the size of those sections of the read-write memory in accordance with his present problem solving requirements.

Abstract: An adaptable programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user, and an LSI NMOS central processing unit, capable of handling sixteen-bit parallel binary operations, binary-coded-decimal arithmetic, sixteen-bit parallel input/output operations, two-level interrupt from up to sixteen input/output devices, and a direct memory access channel.

Abstract: An improved mail box signalling mechanism that may be quickly and easily installed on conventional rural mail boxes provides a flag that is automatically displayed when mail is deposited in the mail box by the postman to give the box holder a positive visual indication that mail has in fact been delivered.

Abstract: A modular read-write and read-only memory unit capable of employing both direct and indirect decimal and symbolic addressing, a central processing unit capable of performing both serial binary and parallel binary-coded-decimal direct and indirect memory register arithmetic, and an input-output control unit capable of bidirectionally transferring information between the central processing unit a number of input and output units are controlled by a microprocessor included in the central processing unit. The input and output units include a keyboard input unit with a section capable of being defined by plug-in read-only memory modules and stored programs added by the user, a magnetic card reading and recording unit capable of bidirectionally transferring information between an external magnetic card and the calculator, and a solid state output display unit capable of displaying three lines of numeric information.

Abstract: A binary adder employs separate summing and carry circuitry within each digit to optimize the speed of operation of the adder. Carry bits of less significant digits are calculated independently of corresponding sum bits, thus allowing propagation of such carry bits to more significant digits before completion of the summation of the less significant digits.

Abstract: A circuit is described which compensates for variation in the threshold voltage of Insulated Gate Field Effect Transistors (IGFETs) in an integrated circuit by modulating the substrate voltage in response to the variation of the threshold voltage from a desired nominal value.

Abstract: An improved and simplified method of fabricating field effect transistors in metal oxide semiconductor integrated circuits advantageously employs the differential growth rate, under certain temperature conditions, between oxide on silicon wherein phosphorous has been diffused, and on silicon without such diffusion. The improved method of fabrication reduces the number of fabrication steps required, while simultaneously producing field effect transistors with superior operation speeds.

Abstract: Vacuum pump exhaust manifold pressure is employed to control the conversion voltage applied during a CRT conversion process for enabling conversion of CRT cathodes in a nearly constant vacuum environment.

Abstract: An information transfer bus circuit useful in metal oxide semiconductor integrated circuits employs a network to compensate for signal losses arising from capacitance associated with gating devices in the circuit.

Abstract: An improved feedback/compensation scheme for a precision active rectifier circuit improves the slew rate and loop gain during diode switching and thereby reduces fractional scale linearity problems.

Abstract: An adaptable programmable calculator is provided by employing a modular read-write and read-only memory unit capable of being expanded to provide the calculator with additional program and data storage functions oriented towards the environment of the user, a central processing unit capable of performing both serial binary and parallel binary-coded-decimal arithmetic, and an input-output control unit capable of bidirectionally transferring information between the memory or central processing units and a number of input and output units. The memory, central processor, and input-output control units are controlled by a microprocessor included in the central processing unit. A keyboard input unit with a plurality of sections capable of being defined by plug-in read-only memory modules and stored programs added by the user, a magnetic card reading and recording unit, a solid state output display unit, and an output printer unit are included among the input and output units.

Abstract: A fingernail and hand cleaning apparatus applies pulsating jets of liquid to the ends of the fingers of a user's hand while the hand is positioned in a grooved hand rest within the apparatus. Additional pulsating jets of liquid are applied to other areas of the user's hand to provide cleansing and massaging action.