Abstract: The present television fine tuning is constructed so that an initial rotation establishes the fine tuning state and that a continued rotation of the fine tuning shaft performs the fine tuning. For this purpose the present tuner comprises a fine tuning driving member, a rotation transmitting idler member, a plate spring for supporting the idler member and a fine tuning adjustment element. The driving member includes a fine tuning shaft, a slide gear and a slip clutch concentrically mounted on the front of the chassis around a channel selector shaft supported by the chassis. The slip clutch has a plastic collar loosely mounted around the selector shaft, and a metallic sheet member located in a gap formed between the inner surface of the plastic collar and the outer surface of the selector shaft.

Abstract: A compact apparatus for the accurate measurement of complex reflection coefficients and VSWR of a device over a bandwidth of an octave or greater by preferably measuring three power levels at detectors associated with the device. The device is formed by the junction of 5 transmission lines two of which are used for receiving a test signal and for transmitting the signal to the device being measured. The other three transmission lines are connected to detector arms each having a detector associated therewith. The techniques of the invention are embodied herein in a waveguide embodiment, a stripline embodiment and a microstrip embodiment of the invention.

Abstract: Apparatus for processing microwave signals at two predetermined frequencies. Signals at a first predetermined frequency are received or transmitted at one end (input port) of a microwave transmission line whose other end is utilized as a common output port for transmitting and receiving signals at both predetermined frequencies. A band rejection portion is provided which comprises first and second rejection resonators orthogonally disposed along the transmission line at two predetermined positions. A bandpass portion, comprised of a plurality of collinearly aligned bandpass resonators, is disposed at a third predetermined position along the transmission line. Signals at a second predetermined frequency are transmitted or received at a second input port which is part of the bandpass portion. All resonators are capacitively coupled together and to the transmission line.

Abstract: The X-ray diffraction apparatus of the invention includes means capable of detecting the position and intensity distribution of the diffracted X-ray with respect to a thin bundle X-ray and means for moving the former means to a position at which the former means is capable of detecting the diffracted X-ray, and makes it possible to reliably and easily carry out rough detection of the position of the diffracted X-ray and fine detection of the intensity distribution of the diffracted X-ray without increasing the size of the diffracted X-ray detecting means.

Abstract: An electronic hybrid voice frequency repeater having a pair of term sets interconnected by a four-wire circuit for separating the two directions of signal transmission and amplifying each direction separately. Each term set couples the repeater's four-wire circuit to a two-wire line and has a differential current driver for driving the two-wire line and a differential amplifier connected in a feedback loop for sensing the differential signal voltage across the two-wire line, to drive the current driver and to feed an incoming differential signal on the two-wire line to the repeater's four-wire circuit while nulling signals arriving at the term set from the four-wire circuit to prevent them from returning to the four-wire circuit. Other features disclosed include a low frequency clamping circuit, an adjustable-gain amplifier, and an equalizer for non-loaded cable.

Abstract: An adaptive equalizer for a twisted pair telephone line comprises a differential input/output amplifier, with the line connected to its positive input via a resistor and DC blocking capacitors. The junction of these capacitors is grounded via an adjustable impedance.The amplifier has a feedback loop with another adjustable impedance also connected to the negative input of the amplifier.Line impedance variations vary the impedance of both of the adjustable impedances, which, include diodes to separately compensate for the line's attenuation and frequency characteristics.

Abstract: An equalizer circuit for communication signals is constructed as an active Bode equalizer employing an amplifier having anti-phase outputs and a bridge circuit connected to the outputs. The susceptibility of the equalizer to manufacturing tolerances is reduced insofar as possible and the transfer function of a passive Bode equalizer is retained, as far as possible, even at frequencies which lie far above 10 MHz.

Abstract: A non-dispersive antenna feed in which a length of strip transmission line (stripline) has two spaced center conductors supported on a dielectric sheet between two ground planes. These center conductors or conductive strips produce an even-mode electric field between the two ground planes when excited in-phase and an odd-mode electric field when the center conductors are excited in anti-phase relationship. A plurality of close-coupled quarter wave conductors parallel one of the center conductors, a feed strip extends substantially orthogonally from each such coupling strip to provide an antenna element feed externally. A four poor hybrid has two external ports and two additional ports for discretely feeding the stripline center conductors in-phase corresponding to excitation of one hybrid external port an in anti-phase corresponding to excitation of the other hybrid port. Each external hybrid port thereby corresponds to a different angle of antenna beam generation.

Abstract: a tri-mode coupler (80) for developing from a received signal including three waveguide propagation modes the three tracking signals (i.e. sum signal, elevation signal, and azimuth signal) used in a high-frequency monopulse tracking system and for transmitting a signal at a different frequency, the coupler comprises broadband means such as a two-arm turnstile junction (84) coupling a first circular waveguide section (82) to an E-plane folded hybrid junction (90) for separating out one waveguide mode of the received signal and receiving the signal to be transmitted, and a second circular waveguide section (86) of smaller diameter than the first waveguide section and coupling the latter section to an additional E-plane folded hybrid junction (88) for separating out the two additional waveguide modes of the received signal.

Abstract: One circuit is a low frequency, wide band multi-directional tap that exhibits good match characteristics with low through loss. The circuit has input and output terminals conductively interconnected, a tap output terminal, an inductive winding having n.sub.1 /n.sub.2 series turns and a series resistor coupling from the tap on the inductive winding to the tap output terminal. The other circuit is a low frequency, wide band multi-directional signal splitter that also exhibits good match characteristics with low through loss. The circuit has an input terminal and two output terminals interconnected by three core transformers each having an isolation resistor associated therewith.

Abstract: A slotline directional coupler is disclosed that introduces a 180.degree. phase reversal in one of the arms of the coupler in order to isolate opposite ports of the coupler. One of the arms of the coupler is split and a quarter wave shorted slotline is added to each portion of the split coupler arm. The split coupler arm is bridged by a short conductive strap that, in a first embodiment, is grounded on both ends to the slotline ground plane or in a second embodiment, is extended to appear as though grounded. In the first embodiment, the conductive strap is separated from the ground plane by air. In the second embodiment the dielectric substrate of the coupler separates the strap from the ground plane. The conductive strap serves as a slotline-to-microstrip-to-slotline transition which introduces a 180.degree. phase shift in a signal propagating through it.

Abstract: A negative resistance element having two terminals (11, 12;) a resistor (R1-4) connected in a path between the terminals, and a current mirror arrangement (T1, T2; T3, T4;) responsive to a current flowing into the first terminal (11) to produce a current through the resistor R1-4 in such a direction as to increase the voltage of the second terminal 12 relative to the first terminal 11.

Abstract: A key assembly for receiving units employed in communications engineering, articularly for television receivers, comprises a plurality of mutually releasable depressible keys adapted to switch on storable, selectively adjustable electrical values supplied by channel memories consisting of a plurality of voltage dividers for capacitance diode tuning, further comprising, in association with the respective depressible keys, a plurality of depressible and rotatable knobs adapted to be rotated by means of a tool, said knobs being concealed behind a cover member slidably guided in a recess, said knobs being adapted to provide channel tuning and, if required, selection of the desired frequency range, said frequency range being adjustable by rotating the respective depressible and rotatable knob into any of a plurality of detented angular positions with the knob being in a position differing from the tuning position of the knob, and comprising a switch which is adapted to be actuated by means of a push rod which is c

Abstract: The dispersive effects of frequency selective fading in a digital, FM, or AM radio system are reduced by means of an adaptive equalizer (11) comprising a cascade of feed-forward stages (1,2, . . . N), each of which includes: a first parallel wavepath (1-1, 1-2, . . . 1-N) including a first adjustable attenuator (20-1, 20-2, . . . 20-N); a second parallel wavepath (2-1, 2-2, . . . 2-N) including a second adjustable attenuator (21-1, 21-2, . . . 21-N) and delay means (22-1, 22-2, . . . 22-N); and means (23-1, 23-2, . . . 23-N) for combining the signals in said wavepaths and for coupling said combined signal to the next stage. By a suitable selection of parameters, according to two unique relationships, a transfer function can be realized which can compensate for amplitude and delay distortions caused by minimum and nonminimum phase fades.

Abstract: Millimeter wave circulators are disclosed for use with millimeter wavelen dielectric waveguides. The structure comprises a prism of magnetized ferrimagnetic material with the waveguide ends bonded to the lateral faces of the prism. The waveguide ends and the lateral faces are congruent rectangles. The prisms may have triangular bases in which case a Y-junction circulator results, or square bases with waveguide ends attached to three out of four of the lateral faces thereof, whereby a T-junction circulator results.

Abstract: A rotatable polarized signal receiver in a system for receiving linearly polarized electromagnetic signals includes a signal conductor having a receiver probe portion, oriented in a circular waveguide parallel to the polarization of the incident signal, and signal launch probe portion extending into the rectangular waveguide orthogonal to the direction of signal transmission therein, mounted concentrically in an insulator rod through perpendicular coupling of the circular and rectangular waveguides.

Abstract: An RF gasket for reducing the flow of energy in the interface area between two conductive surfaces includes a plurality of stub pairs. These stub-pairs are dimensioned to form sub-groups of low impedance paths between the two conductive surfaces with each sub-group being effective in a different frequency sub-band of a large frequency range. The low impedance paths are established without the use of direct current connections between the two conductive surfaces. Such a gasket provides a broadband, non-contacting RF shield in the interface area between the two conductive surfaces.

Abstract: A termination device for a transmission line in which it is desired to reduce to a minimum the standing wave ratio resulting from the reflection of microwaves on a resistive load positioned at the end of the line. For this purpose and more particularly for a microstrip line comprising a conductor deposited on a dielectric substrate, whose lower face is metallized (earth plane), the conductor is extended by a trapezoidal resistive film, whose narrow end is connected to a metal coating connected to earth. Moreover, in order to compensate for the inductance of the load, two capacitors formed by metal deposits deposited on the substrate are connected to the resistive film.

Abstract: There is disclosed an automatic line buildout circuit which includes in its signal path two variable filters, each implemented by a transconductance operational amplifier circuit. Each filter exhibits a transfer function pole with a frequency which is directly related to a control current applied to that filter. At a point in the signal path after the two variable filters, there is a peak detector which provides an output level proportional to the peak amplitude of the signal in the path, and therefore proportional to the cable length. From the peak detector output level, there is derived for each of the variable filters a control current, related to the output level by a preselected function. For each variable filter, the associated function expresses the relation between cable length and the filter cutoff frequency which is required for proper equalization.

Abstract: An improved magic tee constructed to maximize the power that can be transferred from the H-plane arm to the collinear side arms and vice versa. The matching post is designed to maximize the breakdown voltage between the post tip and the walls of the E-plane arm. This is accomplished by selecting the post diameter to produce a ratio of the E-plane arm height to post diameter which develops a characteristic impedance corresponding to that of a coaxial transmission line constructed to withstand the maximum breakdown voltage between the transmission line center conductor and conductive shielding for a given shield separation.