Abstract: A trolley for supporting and transporting units of electronic equipment is provided with a front pair of legs and a rear pair of legs, with horizontal members being integrally formed with each pair of legs. A platform is supported upon the horizontal member of the rear legs and upon a mount member rotatably mounted upon the horizontal member of the front pair of legs. Supporting brackets are fixed to each of the rear legs, upon which are attached retaining brackets, with the horizontal member of the front legs being retained within these retaining brackets in rotatable manner. Link members are rotatably coupled to the lower ends of the legs, in such a way that the entire assembly may be folded together into a very compact space. Greatly increased strength and rigidity by comparison with conventional trolleys is ensured.

Abstract: A test rack for electronic equipment features an improved mechanism for inclining the test rack table in a smooth and effortless manner even when heavily loaded with equipment. Notches provided on a stopper plate are allowed to mate with a stopper shaft by sliding the stopper plate along a guide portion when the table is set at a desired angle of inclination. The stopper plate is constrained to slide at substantially right angles to the stopper shaft at all times so that the stopper shafts engages squarely with the notches to preclude jamming when the mechanism is operated under a heavy load.

Abstract: A power level measurement system includes a power level sensor having a linear response to power level variations for power levels below a predetermined level and a non-linear response above the predetermined level, a DC amplifier and linearity compensator for measuring power and amplitude levels above the predetermined power level, a switched amplifier circuit containing a DC to AC converter circuit, an AC amplifier and a detector for measuring power levels below the predetermined level, means for determining whether the power level of the high frequency signal is above or below the predetermined power level and for accordingly selecting either the DC amplifier or the switched amplifier system in accordance with this power level, and display means for displaying the output from the selected amplifier system.

Abstract: A multi-item data input apparatus for manual generation of data to designate selected ones of a plurality of items, the items being visibly displayed on a flat sheet, comprising a plate having apertures therein in positions corresponding to those of the items on the sheet, a transparent key mounted in each of the apertures and movable therein within a limited range, a contact spring actuatable by each key, and a matrix of conductor elements arranged in rows and columns in relation to the contact springs such that contact between two intersecting conductors is established by actuation of any of the keys, thereby generating data designating the item which is visible through that key.

Abstract: A sweep signal generation system for producing an output sweep signal of very high frequency includes a circuit for generating an input sweep signal, and a phase locked loop which includes a phase detector, a voltage controlled oscillator and a harmonic frequency mixer. The output sweep signal is applied to the harmonic mixer together with a local oscillator signal of fixed frequency, the output from the harmonic frequency mixer being applied to the phase detector together with the input sweep signal. The output from the phase detector is applied to the voltage controlled oscillator to cause the frequency of the output thereof to be swept in accordance with variation of the input sweep signal.

Abstract: A method of testing a plurality of repeaters arrayed along a transmission line of a pulse code modulation system, and of locating any faulty repeaters, both testing and fault location being performed automatically. Pulse train groups, each containing a frequency component corresponding to a supervisory signal frequency of one of the repeaters, are successively applied from one terminal of the transmission line. Each pulse train group comprises a plurality of subgroup pulse trains, each of which contains the supervisory frequency component of the pulse train group to which it belongs, with the density of a pulse train in successive subgroups being successively increased. Any faulty repeater is located by determining the pulse train density at which a supervisory signal produced by the repeater fails to increase by a predetermined amount for a known change in pulse train density.

Abstract: A frequency marker display system for displaying markers on a display device such as a cathode ray tube includes means for generating gating pulses whereby only a desired pair of frequency markers, appearing on each side of a center frequency marker, are displayed. Selection of the side frequency markers is accomplished by an operator-actuated switch which produces a DC signal, this DC signal being compared with the level of a sweep repetition rate controlling signal, and said gating pulses are produced when the levels of said DC signal and that of said sweep repetition rate controlling signal coincide.

Abstract: An automatic Y-axis offset system for a cathode ray tube, which performs automatic positioning of a trace to a predetermined position on the cathode ray tube face such that the trace becomes visible, by applying a Y-axis offset voltage to the input signal voltage. The automatic positioning is performed when commanded by an operator through switch actuation. The offset voltage is produced by a feedback circuit which includes an amplifier receiving the input signal, a comparator for comparing an output voltage from the amplifier with a predetermined level, a counter which is enabled to count a clock signal so long as the level of output signal from the amplifier is different from the predetermined level, and a digital-to-analog converter which converts the count in the counter to an analog signal constituting the Y-axis offset voltage.

Abstract: A multi-item data input apparatus for manual generation of data to designate selected ones of a plurality of items comprises lists of items visibly written in matrix array form on a number of sheets, with the sheets being rolled around a cylindrical holder in successively overlapping relationship. Means are provided for unrolling a selected one of the sheets such as to position the corresponding item array below a keyboard having a transparent key above each item. Actuation of a key causes an electrical signal designating the corresponding item to be generated.

Abstract: The local signal generation arrangement employed in a radio communication system for transmitting and/or receiving an upper sideband (USB) and a lower sideband (LSB) signal, but not simultaneously, employs a method in which the generation and/or detection of both USB and LSB signals is accomplished by utilizing only one bandpass filter, a so-called single sideband (SSB) filter, together with a balanced modulator arranged to receive a carrier signal produced from an oscillator whose frequency is accordance with the characteristic frequency of either of a pair of crystal resonators, which correspond to the upper cut-off and the lower cut-off frequencies of the SSB bandpass filter, respectively. The output signal from the said SSB filter is referred to herein as the intermediate frequency (IF) signal.The local signal generation arrangement includes a phase-locked loop (PLL) including at least a phase comparator, a low pass filter, and a voltage-controlled oscillator (VCO).

Abstract: An amplitude modulation circuit which comprises a modulating circuit for applying a modulating signal to a modulated stage, and a voltage regulator arranged to regulate a D.C. voltage to be supplied to the modulated stage at a predetermined constant level and having a circuit means adapted to provide a high impedance for the modulating signal applied to the modulated stage.