Abstract: Relationship discovery can include receiving at a first mobile device a pair of ultrasonic signals conveyed at different frequencies from a second mobile device. The pair of ultrasonic signals can convey, respectively, a second user's contact information in an encrypted form and a key indicator. A contact number can be selected from a first user's contact list electronically stored on the first mobile device. The contact number can be selected based on the key indicator. A mutual contact can be identified in response to decrypting the second user's contact information using the contact number as a decryption key.

Abstract: A system includes a filter and a tuner formed on an integrated circuit. The filter receives an input signal comprising a first number of channels and communicates an intermediate output signal comprising a second number of channels less than the first number of channels. The tuner is coupled to the filter and receives the intermediate output signal and communicates an output signal comprising a third number of channels less than the second number of channels.

Abstract: An electronic alignment system for a television signal tuner utilizes first and second controllers for generating respective first and second control signals for respective first and second signal processing circuits of a signal processing arrangement, with the first and second signal processing circuits having respective first and second tunable elements responsive to the respective first and second control signals. A deviation range of the first control signal is higher than a deviation range of the second control signal.

Abstract: An electronic tuning system for radio receivers, with digital memorization of the signal frequencies. A manual control generates a first control voltage. A clock pulse generator applies pulses to a counter, the output of which is connected to a digital-to-analog converter to supply a second control voltage, indicative of the number of clock pulses counted by the counter, to electronic tuning circuitry of an electronically tuned radio receiver. A voltage comparator receives the digital-to-analog converter output and the output from the manual control. The output of the voltage comparator is applied to a gate circuit which controls application of the clock pulse signals to the counter so that these signals are discontinued when the output signal from the digital-to-analog converter is substantially equal to the output from the manual control.

Abstract: In a radio having power tuning apparatus activated by a latching switch in a sweep position and deactivated by the latching switch in a stop position, the radio further having apparatus responsive to a received radio frequency signal for switching the latching switch to its stop position, first apparatus is provided for switching the latching switch to its sweep position, second apparatus is provided for manually disabling the first apparatus, third apparatus is provided for activation of the first apparatus, if not disabled, a first predetermined time delay after the switching of the latching switch to its stop position, the first predetermined time delay permitting recognition of a received radio signal and activation of the second apparatus, and fourth apparatus is provided for deactivating the first means a second predetermined time delay after the switching of the latching switch to its sweep position, the second delay being just long enough to ensure latching of the latching switch in its sweep position

Abstract: A search tuning circuit for two search directions which includes a starting signal memory having a starting signal input. A search direction signal memory having first and second operating signal inputs is coupled to the starting signal input of the starting signal memory and to first and second search direction signal inputs of the search direction signal memory. The circuit is responsive to an operating signal at an operating signal input to write a search direction signal for a certain search direction at a starting in the corresponding memories. This circuit further include a gating circuit which in the event of simultaneous operating signals at the first and second operating signal inputs a starting signal will occur only at the starting signal input of the starting signal memory without a search direction signal being generated.