Abstract: A UHF broadcast antenna system uses circular waveguide for the run from the high-power final amplifier to the antenna. Undesired cross-polarization components are formed in the circular waveguide due to unavoidable tolerances. Correction of the cross-polarization components is accomplished by a correction apparatus for sampling the principal polarization-plane signal, and reinjecting the sample with controlled amplitude and phase into the circular waveguide in the plane of the cross-polarization component for cancelling the cross-polarization.

Abstract: An improved companded transmission system uses a transmitter having a first compressor for compressing a signal m(t) of bandwidth B.sub.1 to form a signal C[m(t)]. The transmission system has a bandwidth B.sub.2 where B.sub.1 .ltoreq.B.sub.2. A receiver having an expander to expand the received signal r(t) is provided to produce a signal m.sub.E (t). The improvement consists of a circuit for recovering the frequency components f.sub.L lost during transmission of C[m(t)] and includes a second compressor for compressing m.sub.E (t) in the same manner as m(t) was compressed to produce a signal C[m.sub.E (t)] which contains frequency components f.sub.c lying above B.sub.2. A filter which is responsive to C[m.sub.E (t)] generates (C[m.sub.E (t)]-f.sub.c), and, a subtractor subtracts (C[m.sub.E (t)]-f.sub.c) from C[m.sub.E (t)]. An adder adds f.sub.c to r(t), and, an expander expands the summed signal f.sub.c +r(t) to produce a signal m.sub.1 (t) which is a first order corrected approximation of m(t).

Abstract: In a signal transmission system comprising a transmitter, a transmission medium, and a receiver which collectively form a transmission path, an improvement for processing the signal to enable the transmission thereof over a narrower bandwidth and comprising first logic for decreasing and increasing, respectively, the rate of change of amplitude (dA/dt) of first and second portions of the signal, respectively, whose dA/dt's exceed or are less than a predetermined dA/dt, by amounts which increase at a non-linear rate as the dA/dt of the first and second portions increase or decrease, respectively, to produce a processed signal whose maximum and minimum dA/dt's define a bandwidth narrower than that of the unprocessed signal. Second logic is provided for altering the dA/dt of the processing signal at the receiver in a manner which is the reciprocal of the changes in dA/dt which occurred at the transmitter to reproduce the unprocessed signal.

Abstract: An error concealment system for a digital video signal uses different methods of concealment in accordance with the severity of the error. An adaptive estimate (horizontal or vertical average) is used if all pixels need for such an estimate are valid. If not, a four pixel average is used. If that is not possible a vertical average is used, and finally a horizontal average is used. If the error is very severe, then a line store provides the last valid line.

Abstract: When a caddy is inserted into the player to load a record therein, it displaces a switch actuating lever to a second position thereof to turn on the player. The switch actuating lever moves back to its first position upon retrieval of the record from the player as the carriage is driven toward its OFF position to switch off the player.

Abstract: A matrix for digital video signals separates each coefficient into a binary part and a remainder. The binary part can be implemented very simply by a hardwired right shift. The remainder can be implemented using a ROM. Less ROM memory space is required than for implementing the entire coefficient in a ROM.

Abstract: A phase detector for digital signals, such as television sync signals, provides a signed short path output of the phase difference between the signals. It features a means for determining which of the signals is leading and lagging, which means also provides the sign signal. A window signal is generated and clock pulses are counted during the duration of this signal. A register can provide an exact phase difference measurement or a coarse/fine output signal can be provided.

Abstract: A television standards converter uses a VTR. The capstan speed is that of the video signal recorded on the tape, however, the drum speed is that of the standard to which it is desired to convert. Thus the reproduced signal has the original line rate but the new field rate. A line rate converter converts the reproduced signal to the new line rate, the signal is now totally in the new standard.

Abstract: A television camera or other source of color-representative signals such as R, G and B includes a matrix to which the R, G and B signals are applied to form luminance (Y) and color-difference (I,Q) signals. The source and matrix are coupled together by way of a signal path having a particular response or transfer function for the R, G and B signals over their normal range. Unavoidable noise occurring in the signals near black level may perturb the color-representative signals, and causes color errors. The errors are reduced by arranging the coupling to have a response to negative noise peaks into the blacker-than-black region. The response outside this normal range is complementary to the response within the normal range. In a particular embodiment the coupling includes a gamma corrector which has complementary response in the blacker-than-black region.

Abstract: A genlock circuit has a reference signal that is frequency divided to provide an internal vertical sync signal. When an external sync signal is present, the division ratio is temporarily changed to provide a slow locking of the internal sync signal to the external sync signal. This avoids picture disturbances. The circuit can be used in a camera control unit and camera heads.

Abstract: A television transmitter uses a diplexer to combine the signals from a visual power amplifier and an aural power amplifier. The diplexer uses hybrids coupled together by transmission lines, and the transmission-lines have aural-frequency cavities which reflect the aural energy from the aural input port to the antenna output port. In the event that the aural power amplifier fails, it is desirable to revert to multiplexed operation, in which the visual amplifier amplifies combined visual and aural signals. This mode of operation is accomplished by switching the low-level aural signal for combining with the low-level visual signal and by simultaneously switching the tuning of the aural cavities.

Abstract: A digital sync separator has a separator for supplying composite sync from composite video. A counter counts clock pulses and is reset by the composite sync signals and one of its outputs. The separator can comprise a pair of controlled switches, one switch being a clamp, the other supplying a signal to a low pass filter and attenuator, and a comparator to compare the composite video with the attenuated signal.

Abstract: A group delay compensation circuit for a television transmitter comprises a signal source coupled to a series resonant circuit. A means is present for changing the resonant circuit Q without changing the amplitude of an output signal derived from the resonant circuit. A difference amplifier is coupled to the resonant circuit and to the signal source. The means can be a voltage divider and a variable resistor coupled to the divider. Changing the Q varies the group delay.

Abstract: A TV camera comprises a pair of CCD imagers subject to defects. Defect detection is done by comparing signals from the imagers, thus saving the expense of a defect location memory and also detecting more kinds of defects than one would detect by just comparing one signal to a fixed reference. As a result, CCD imagers with defects can be used thus increasing production yield of such imagers.

Abstract: A broadband antenna features a diamond-shaped radiator. The radiator can be bent to form a selected dihedral angle to achieve omnidirectivity when a plurality of antennas having reflector screens are used. Two pairs of radiators can be placed in the turnstile configuration. A pair of shorted tubes can be used as a combination feed means and balun to avoid a separate balun.

Abstract: A tape has Y and C components of a television signal recorded in different tracks. This can lead to mistiming and hence misregistration errors. To correct this a phase error signal is generated from the horizontal sync signals in each track and used to control variable delay lines for the Y and C to correct the misregistration. Separate delay lines for the I and Q components can also be used.

Abstract: When PAL chroma signals U and V are respectively recorded in channels with bandwidths intended for NTSC chroma signals I and Q, distortion will result to one of the U or V signals due to the narrow bandwidth Q channel. To equalize this distortion between the U and V signals, they line to line alternate between the two channels. To avoid a line crawl, signals above the Q channel cut-off frequency are averaged.

Abstract: Apparatus for the manufacture of a video disc caddy sleeve comprising folding platens, an intermediate spacer plate with indentations on the leading edge, and a selective heating means. Spacer plate causes plastic sheet to bend in the middle while folding platens close to a folded up position. Indentations on the leading edge act to keep label, already adhered to plastic sheet, from tearing while sheet is being bent into a U-shaped enclosure.

Abstract: A dithered automatic scan tracking system for a videotape playback machine includes a bimorph which with its associated load has a mechanical resonance. In special-effects operating modes, the jump or reset signal which drives the bimorph at the end of its scan to position the playback transducer for the next track excites the mechanical resonance, which causes incorrect demodulation of the detected FM envelope and therefore causes generation of an incorrect AST loop error signal until the excited resonance dies away. A gated phase-lock loop is coupled to the bimorph position sensor and produces clock signals for control of the demodulation of the detected FM envelope. The gate decouples the position sensor from the phase-lock loop during recurrent intervals including those intervals during which the mechanical resonance is excited. This allows generation of a correct error signal immediately after the jump and reduces mistracking.

Abstract: A television camera-recorder combination includes an imager which forms a signal representative of the image during an integration interval. The integration interval is followed by a pull-down interval during which the integrated signal is transferred out of the photoresponsive region. Streaking of an image displayed from the signal results from light falling on the photoresponsive region during the pull-down interval. A mechanical shutter periodically prevents light from falling upon the photoresponsive region of the imager. The shutter is synchronized with the pull-down interval. The synchronization and drive arrangement of the video recorder portion is mechanically coupled to the shutter to provide a common drive. In another embodiment, a color wheel associated with the viewfinder of the camera is mechanically coupled to the video recorder drive arrangement for common mechanical drive.