Abstract: A method for operating a jukebox having a disc changer (2) for discs (3) containing a plurality of music titles, particularly CDs, at least one disc magazine (6), at least one playback unit (7), a computer-controlled disc-transport device (8), and a display device (9) for displaying the music titles of the discs (3), with an associated address (12) that encompasses a respective disc address (10) and a title address (21), wherein the music titles of a disc (3) are displayed together and selected through keystrokes. To improve the selection of music titles, individual music titles of different discs (3) are combined into a group (18), assigned a new target address (19) that encompasses a group address (20) and a title address (21), and displayed together as a group (18) in the display device (9). Depending on the programming, the groups (18) can expand or limit the title selection.

Abstract: A simplified and improved object testing system which, according to the present invention, includes a first and a second imaging system for generating a radiograph of the object as a visible image on a monitor, and a common operating unit controlling the first and second imaging system.

Abstract: A new method is presented which converts the phases and frequencies of HF and microwave signals into sequences of digital words. This phase quantization is 10 times faster compared to conventional amplitude quantization by means of extremely fast A/D converters. In this method, n parallel shifted signal phases are initially derived from the HF signals by means of a signal phase generator, and in a bank of comparators these signal phases are then converted into rectangular oscillations (sequences). A subsequent digital sampling of these sequences then furnishes the phases of the HF signals as digital values at the output of the circuit.

Abstract: A method and a circuit for determining the momentary frequency of an analog signal s(t) which is variable over time within a given frequency bandwidth .DELTA.f, as an N-bit number in an N-bit coding range. The circuit includes N detector cells which operate in parallel according to the interferometer principle directly in the original frequency range, to produce respective bit values of the momentary frequency according to a digital code, the bit positions of the code having either odd or even bit functions with respect to the middle of the coding range, depending on the code. Each cell receives from a signal/phase distributor different phases of the signal and with the use of delay elements, comparators and EX-OR and/or EX-NOR gates, depending on whether the cell corresponds to a bit position having an even or an odd bit function, produces an output according to a corresponding equation. For an i-th cell corresponding to the i-th ordered bit position of N, having an odd bit function, the output squ.sub.