Abstract: There is disclosed a technique for providing resynchronization for message reception in digital transmission systems, and particularly in digital frequency hopping systems employing data framing techniques. In the transmission of framed data using known digital techniques for frequency hopping systems, synchronization is provided in frames preceding the message frames transmitting digital data. In addition, resynchronization information is transmitted in subsequent frames which are interspersed with data frames including the message data. A predetermined number of frames is set to provide all the resynchronization information so that once those frames have been detected, a receiver will have acquired resynchronization during message transmission. This technique allows improved signal acquisition by providing an opportunity following the first conventional synchronization frame to acquire synchronization or to reacquire synchronization during message transmission.

Abstract: Disclosed are a method and a matrix panel masking apparatus for forming very closely spaced, parallel, elongated, narrow, and electrically separate conductors on a dielectric surface. The matrix panel masking apparatus comprises a plurality of elongated taut wires, being arrangable in a configuration so that the interstices between the wires correspond to the desired matrix panel conductor pattern. The method includes: superposing the matrix panel masking apparatus of this invention on the dielectric surface, depositing conductive material through the interstices and on the dielectric so that after the masking apparatus is removed, the conductors will remain.

Abstract: The presently-disclosed invention utilizes sensed pitched rate and sensed vertical acceleration to prevent aberrant pitch rate command outputs as a function of lead compensated sensed acceleration, controlling the vertical acceleration by sensing when a maximum is approached. When the lead compensated acceleration exceeds a first predetermined acceleration factor, the presently-sensed pitch rate replaces the pre-programmed maximum pitch rate factor as the temporary maximum rate, to temporarily prevent additional vertical acceleration due to increasing pitch rate. This apparatus requires no airspeed input and does not interfere with flight performance characteristics during normal flight operations, allowing higher torque servos to be used, and thus improves overall performance.

Abstract: A ceramic TEM resonator bandstop filter is disclosed wherein the direct inter-resonator coupling is retarded by a plurality of shorting holes which are positioned between the resonators and extend from the top surface to the bottom surface of said ceramic filters. Furthermore, there is disclosed a transverse electrical connector which electrically connects the shorting holes with the opposite sides of the typical metalization found on ceramic TEM resonator filters. Furthermore, there is disclosed a method of making a capacitor for each resonator with the bottom capacitor pad being formed directly upon the top surface of the ceramic of the filter while the top capacitor pad is formed upon the top surface of a circuit board which is placed above the top surface of the filter.

Abstract: The apparatus and method of this invention pertain to the sharpening of the blades of a reel mower having a framework about the reel. The apparatus comprises a belt having protuberances thereon, an assembly of pulleys and a drive motor for driving the belt and guiding the belt and protuberances to engage with the blades of the reel mower. The method of the invention is to use the apparatus of this invention and place it in a position so that, when the belt is revolved about the pulleys, the protuberances engage the blades of the reel mower thereby causing the reel to rotate in an opposite direction from the belt movement.

Abstract: An inhomogeneous ceramic dielectric microwave RF TEM resonator filter having a plurality of unplated notches in the ceramic for enhancing direct inter-resonator coupling. The filter is implemented without the lumped coupling capacitors which are typically associated with each resonator of a TEM resonator filter. Furthermore, the launching resonators which are typically used to couple in and out of the filter are eliminated by using coaxial probe capacitors inserted in each of the end resonators. The non-end resonators can be made to look as long as the end resonators, with probes therein, by including a conductor pad disposed upon the block top surface and connecting the internal plating of the non-end resonators.

Abstract: An encoder system and technique is disclosed for providing greater resolution for position indications. The encoder includes multiple small absolute encoders coupled through a fixed gear ratio to provide an increase in the number of positions which may be absolutely resolved by the encoder without a significant increase in the size of the encoder. The resulting configuration produces a size which is the sum of the individual sizes of the multiple encoders but produces a resolution which is proportional to a multiplication of the individual encoder positions. The resulting encoder provides an absolute indication of position without the requirement for knowledge of the previous position or a predetermined rotation prior to position indication.

Abstract: A ceramic TEM resonator bandpass filter with varactor tuning is disclosed. The varactor is located within the resonator holes of a ceramic TEM resonator filter, and is positioned within said holes immediately above the upper extent of the metal plating forming the resonator in said resonator holes. The placement of the varactor in such a manner reduces the interference caused by the varactor in the interresonator coupling. A new apparatus for positioning the varactor within the resonator hole is disclosed and basically includes a conductive rod which at its top end receives the varactor.

Abstract: An amplifier signal limiter is disclosed which has the operational capability of tracking slowly varying signal components while precluding errant transient outputs, and has a programmable limit range which is independently controllable for broader or narrower allowable outputs.

Abstract: An improved vapor phase soldering process and apparatus are disclosed having particular application to electronic circuitry designed for operation at frequencies higher than 1 MHz. A printed circuit board having a defined circuit pattern on both sides is clamped between two parallel clamping fixtures, one having circuit matching characteristics for the specified PC board, and the fixture further having vents allowing vapor phase gas access to the PC board and soldering process waste gasses egress from the soldering area. This process and apparatus allows shortened soldering time, and improves performance characteristics of the PC board by improving the conduction characteristics of the defined circuit pattern.