TVRD receiver system with automatic bandwidth adjustment

In a TVRO receiver for receiving signals broadcast over a plurality of channels with varying bandwidths and having a tuner producing output signals corresponding to selected ones of said received signals and having bandwidths which vary from channel to channel, the improvement comprising

• bandpass filtering means receiving said output signals and having a controllably adjustable pass band,
• bandwidth detecting means for receiving the output signals passing through said filtering means, said detecting means being responsive to a current output signal corresponding to the channel being received for producing a control signal indicative of the extent of deviation of the bandwidth of the current output signal beyond the current pass band of said filtering means,
• control means responsive to said control signal for adjusting the pass band of said filtering means to accommodate the bandwidth of the current output signal corresponding to the channel being received, if the bandwidth deviation of said current output signal exceeds a predetermined threshold value, and
• means for amplifying the output of said filtering means before it reaches said bandwidth detecting means, and means associated with said amplifying means for automatically adjusting the gain of said amplifying means in response to said control signal from said bandwidth detecting means so as to maintain the amplitude of said output signal within a relatively constant range regardless of the width of the pass band of said filtering means.

In a TVRO receiver for receiving signals broadcast over a plurality of channels with varying bandwidths and having a tuner producing output signals corresponding to selected ones of said received signals and having bandwidths which vary from channel to channel, the improvement comprising

• bandpass filtering means receiving said output signals and having a controllably adjustable pass band, said filtering means comprising a plurality of IF passband filters for receiving signals having bandwidths which vary from channel to channel, said filters having pass bands of different widths,
• bandwidth detecting means for receiving the output signals passing through said filtering means, said detecting means being responsive to a current output signal corresponding to the channel being received for producing a control signal indicative of the extent of deviation of the bandwidth of the current output signal beyond the current pass band of said filtering means, and
• control means responsive to said control signal for adjusting the pass band of said filtering means to accommodate the bandwidth of the current output signal corresponding to the channel being received, if the bandwidth deviation of said current output signals exceeds a predetermined threshold value, said control means including switching means associated with said filters and responsive to said control signal for feeding said output signals to a selected one of said filters having a passband corresponding to the bandwidth of the current output signal.

In a TVRO receiver for receiving signals broadcast over a plurality of channels with varying bandwidths and having a tuner producing output signals corresponding to selected ones of said received signals and having a bandwidths which vary from channel to channel, the improvement comprising

• bandpass filtering means receiving said output signals and having a controllably adjustable pass band,
• bandwidth detecting means for receiving the output signals passing through said filtering means, said detecting means including peak detection means responsive to a current output signal corresponding to the channel being received for producing a control signal indicative of the extent of deviation of the bandwidth of the current output signal beyond the current pass band of said filtering means,
• control means responsive to said control signal for adjusting the pass band of said filtering means to accommodate the bandwidth of the current output signal corresponding to the channel being received, if the bandwidth deviation of said current output signal exceeds a predetermined threshold value, said control means including means for adjusting the pass band of said filtering means in response to (1) a signal deviation of said output signal beyond a first predetermined threshold outside the current pass band, or (2) repeated deviations of said output signal beyond a second predetermined threshold outside the current pass band, said second threshold being closer to the existing pass band than said first threshold.

In a TVRO receiver for receiving signals broadcast over a plurality of channels with varying bandwidths and having a tuner producing output signals corresponding to selected ones of said received siganls and having bandwidths which vary from channel to channel, said tuner being fed by means provided in the receiver for receiving the broadcast signals and converting said signals to first IF signals, said tuner receiving and converting said first IF signals to a second IF frequency range, demodulator means provided in the receiver for receiving said second IF signals and producing output signals which vary in proportion to deviations in the frequency of said second IF signals from the center frequency of said second IF frequency range, the improvement comprising

• bandpass filtering means receiving said demodulator output signals and having a controllably adjustable pass band,
• bandwidth detecting means for receiving the output signals passing through said filtering means, said detecting means being responsive to a current output signal corresponding to the channel being received for producing a control signal indicative of the extent of deviation of the bandwidth of the current output signal beyond the current pass band of said filtering means, and
• control means responsive to said control signal for adjusting the pass band of said filtering means to accommodate the bandwidth of the current output signal corresponding to the channel being received, if the bandwidth deviation of said current output signal exceeds a predetermined threshold value.