Abstract: A portable security device (10) for setting up secure powerline modem networks is disclosed. The portable security device includes a memory (18) which stores a protocol (19) for communicating with powerline modem devices (e.g., 22), and a socket (14) configured to receive a power cord (23) from a powerline modem device (22). A number assigning device (12 or 16) transmits a private key to powerline modem devices such that the private key is stored in the powerline modem devices and is used to associate a plurality of powerline modem devices and exclude unauthorized powerline modem devices.

Abstract: A communications system for transmitting and receiving remote control messages in an electronic remote control system. The present communications system uses a remote control message protocol which is particularly suitable for transmitting RF remote control messages with IR remote control messages in a time multiplexed fashion, wherein the RF remote control messages are transmitted during the pause intervals between IR remote control message transmission intervals. The present remote control message protocol includes a start sequence, comprising a MARK pulse and a SPACE of about equal duration, followed by a plurality of data fields. Each data field ends with an End of Field marker and the remote control message ends with an End of Message marker.

Abstract: A method for compatibly tuning a video signal receiver to an image processing device involves generating a prompting message for display to prompt a user to initiate a command response. First and second signals are generated. Each signal incorporates the prompting message but only one of the signals is compatibly tuned to the display. The first and second signals are alternately provided to the display and the prompting message is legibly displayed when the compatibly tuned signal is provided. The signal that is compatibly tuned to the display is selected in response to the command.

Abstract: A satellite video receiver (12) for providing output signals to a television signal receiver (52) includes apparatus (10, 15, 16, 20, 45, 60, 65, 70) for operator selection of the modulator output channel frequency of the satellite receiver. The operator may select a modulator main channel, or an alternative manufacturer pre-set modulator default channel. In a first recovery mode, the operator may automatically replace an existing modulator channel with a manufacturer pre-set default channel, e.g., if a chosen main channel is forgotten. In another recovery mode, the operator may automatically re-establish a previously selected modulator main channel recalled from memory.

Abstract: An economical tuning system for a digital satellite television receiver includes a phase locked loop (PLL) tuning control IC of the which is normally used in a tuning system of a conventional terrestrial broadcast or cable television reciever to control the frequency of the local oscillator (LO). Unfortunately, the PLL IC is only capable of changing the frequency of the LO in relatively large steps. As a result, the operation of a carrier recovery loop which demodulates the digitally encoded IF signal produced by the tuner may be interrupted during a fine tuning mode because the carrier recovery loop may not be able to track frequency changes of the LO. To reduce such possibility, the integrator filter associated with the PLL IC is modified to decrease the rate of change of the LO frequency during the fine tuning mode.

Abstract: A tuner of for a digital satellite television receiver comprises a single conversion stage which produces an IF signal at a low enough frequency to permit a SAW filter to be used to perform symbol shaping as well as the normal IF filtering function. The local oscillator is controlled by a phase locked loop tuning control IC normally used to control the local oscillator of a tuner of a conventional broadcast or cable television receiver. In an exemplary embodiment for tuning RF signals provided by a block converter in the 950 to 1450 mHz frequency range, the IF has a center frequency of 140 mHz.