Abstract: Disclosed is a training device useful to people who play guitar or similar stringed instruments. Its main purpose is to build hard callus pads on the ends of the fingers used in chording the guitar. Its secondary purpose is to strengthen the muscles used to press strings against frets. To accomplish the first, the device is provided with raised edges simulating the cross-section and texture of actual guitar strings. To meet the second need, the edges are mounted on a spring loaded button to simulate the give and tension felt in making chords. The entire device is easily held and fits in any pocket or purse.

Abstract: Disclosed is an improved SAW monolithic convolver using dispersive interdigital transducers designed by a novel technique that allows systematic compensation of phase errors arising in other parts of the convolver. The invention involves a small change in the positional relationship among the electrodes in the input transducers. This change is calculated to be just sufficient to cause a phase error exactly equal to, but of opposite sign to, the aforementioned phase errors.

Abstract: A dielectric waveguide of rectangular cross-section has periodically spaced, transverse slots in its upper surface. When traveling waves of varying millimeter wavelength frequencies are applied to the waveguide, the slots perturb the waves resulting in radiation having a main lobe that scans as the frequency changes. The antenna is made rigid by the use of a dielectric support.

Abstract: The structure of a thin film electroluminescent device wherein an insulating layer (Y.sub.2 O.sub.3) is disposed between a pair of outer active layers of doped semiconductor (ZnS:Mn). Contiguous to one outer layer of ZnS:Mn is a metal electrode while a transparent electrode is contiguous to the other outer ZnS:Mn layer. The composite structure, moreover, is formed on and supported by a glass substrate. Electroluminescent phenomenon occurs primarily at the layer interfaces upon the application of an alternating voltage applied across electrodes. Such a structure is more resistant to failure due to the fact that the ZnS:Mn layers next to the electrodes act as current limiting layers for preventing breakdown and destruction of the metal electrode for a certain applied voltage which would otherwise occur in electroluminescent structures having the active ZnS:Mn layer sandwiched between two insulating layers.

Abstract: An electronic detection system for detecting intrusion thru a perimeter eoys a transmission line as a sensing element. In one embodiment, RF energy is transmitted: in another, pulses of DC. In either case, pseudo-random coding of the signals is employed. A preferred emboidiment of the invention utilizes a transmission line consisting of a twisted pair of wires enclosed in a non-deformable insulation and configured for shallow burial to effect concealment. Another shape is disclosed for laying-out over hard ground. A low ohmic ground is included under the line to improve performance. An intruder in the field of the line causes an RF reflection back towards the source, which reflection may be detected by Doppler range-gating techniques.

Abstract: This system is a combination of two techniques which are used together effectively combining their features. One technique is an absolute measurement based on mass accumulation rate and used primarily for calibration purposes. The mass accumulation rate on a filter, when divided by the flow rate of the medium through this apparatus, yields the droplet density. The second technique is a differential measurement with two adjacent sampling inlets, one is unrestricted while the other is inertially filtered to eliminate water droplets. The two flow streams in the differential system are cyclically sampled and the combined flow passes a heated wire grid designed to evaporate droplets encountered. The resulting oscillating signal (with DC component) is fed into a lock-in amplifier whose output is the rms value of the difference signal. The vapor component is thereby nearly eliminated and the signal is processed by the phase-locked signal-to-reference detection technique which produces very high sensitivity.

Abstract: A Y-junction dielectric waveguide circulator is provided with a dielectric upport plate. At the vertex of adjacent dielectric waveguides are positioned metal tuning legs. These tuning legs are spaced from the waveguides and extend higher than them. Preferably the tuning legs are made integral with a cap positioned above the circulator junction. This cap also serves as a holder for the upper biasing magnet. The lower magnet is centered under the junction and bonded to the bottom of the support plate.

Abstract: A fast risetime, high voltage, high impedance voltage probe utilizes a parallel R-C divider with damping and compensation circuitry to allow measurement of voltage from DC to picosecond pulses. A unique feature of this probe is its construction. The performance of this device is made possible by utilizing microwave chip components on a planar circuit used as the center conductor of a coaxial transmission line.

Abstract: An apparatus and method for precisely measuring the angles of cut of single nd doubly rotated cuts of quartz crystal blanks on a high volume production basis.

Abstract: The invention is an improved manufacturing technique for producing a certain class of Surface Acoustic Wave (SAW) devices, namely those having input and output transducers in close proximity. A much higher manufacturing yield results from eliminating the cutting of a slot in the substrate between input and output transducers as formerly done. This frequently destructive step is replaced by ion-milling of a deep groove between the ports and backfilling with a metal of proper configuration to provide electromagnetic shielding. The technique produces a new device that is at least equal to the prior art in rejection of unwanted couplings between input and output.

Abstract: An interlock arrangement in which each service request path comprises two inverter gates between an input and an output with a junction between the gates. Cross-coupling circuits are coupled from each junction to every other junction in each direction, each comprising an inverting gate in series with a diode. The diodes are normally reverse biased. A first to arrive request signal is forwarded to its output, and a later signal at any other input causes one diode to conduct and clamp the junction at its output, so that the signal is blocked from reaching the output until the first request signal returns to the inactive state.

Abstract: A millimeter wave line scanner is disclosed providing steered fan-shaped ms from opposite faces at substantially equal angles of a semiconductor waveguide, rectangular in cross section, and having a plurality of equally spaced metallic perturbations or strips disposed on one of the two radiating sides or faces. Different angles of scan are selectively obtained by means of at least one distributed longitudinal PIN diode formed on an adjoining side of the semiconductor waveguide having electrical circuit means coupled thereto for controlling the diode's conductivity which acts to change the guide wavelength and accordingly cause a variation in radiation angle of the two equal beams radiating from opposite faces. The waveguide with one or more PIN diodes may also be used as a phase shifter. To reduce losses, a dielectric insulating layer is disposed between each PIN diode and the waveguide, which prevents the propagation of the wave into the PIN diode.

Abstract: The device features the elimination of bending moments in all members to ow a design of minimal weight, and depends on the use of an existing structure to provide stabilizing reactions when erected. A rigid mast is pivoted at its lower end on the existing structure, and supports a block and tackle at its upper end. A rigid triangular spreader and cable assemblies support the mast.

Abstract: Positional sensitivity of a Kipp type generator with respect to a gravitanal field is achieved by utilization of one or more selectively oriented gravitational sensitive valves in the chamber containing the liquid capable of providing the desired gaseous output. The gravitational sensitive valves may be used individually or in combination. Each valve permits operation when it has an orientation corresponding to a predetermined orientational range. A chamber whose geometrical shape is a parallelepiped employs an arrangement of four gravitational sensitive valves to provide gas generator operation independent of its orientation in a gravitational field.

Abstract: A loop-around doppler canceling loop is employed between a master ground minal or node and a slave ground terminal or node for translating a doppler-free reference to the slave terminal by having a local voltage controlled oscillator (VCO) of frequency f at the master terminal lock to a frequency f.sub.o =f.sub.d where f.sub.o is frequency of the primary standard reference clock 8 at the master terminal and f.sub.d is the two-way doppler frequency that exists during transmission between the master and slave ground terminals by way of satellite.

Abstract: A pulse train generator comprising a shift register with feedback for proing an output pulse for every m clock pulses applied to the shift register stages. The feedback shift register normally has a maximal length 2.sup.n -1, where n is the number of stages. Clock pulses are applied to the shift register until an all-ONE condition is reached; thereupon, (m-1) additional clock pulses are applied and the states of the register stages can then be sensed. Appropriate gate circuits are added to the shift register, depending upon the sensed register states, to inhibit certain shifts and to insure that the register is returned to the all-ONE condition upon arrival of every mth clock pulse.

Abstract: A phase sensing device is described which is useful for indicating the reance condition of a complex load impedance (such as an antenna), with a high degree of accuracy over the frequency range from 3 to 100 MHz. The device uses readily available transmission line and solid state components to provide a .+-. indication of the phase condition of the load; a zero crossing indicates resonance. Such a signal is useful for controlling an automatic turning mechanism that could be used in a tunable antenna. The extremely broadband operation and no physical connection to the main RF line are salient features of the device. The components are a transmission line coupler with a short pick-up wire mounted adjacent to the center conductor, two diodes with like electrodes (cathodes) connected to opposite ends of the pick-up wire, a carbon resistor between the other electrodes of the diodes, and a zero center meter across the resistor.

Abstract: A pulse train generator comprising a shift register with feedback for proing an output pulse for every m clock pulses applied to the shift register stages. The feedback shift register normally has a maximal length 2.sup.n -1, where n is the number of stages. Clock pulses are applied to the shift register until an all-ONE condition is reached; thereupon, (m-1) additional clock pulses are applied and the states of the register stages can then be sensed. False count correction is obtained by the combination of a detector and an analog integrator.