Abstract: A very fast peak detector having feedback is presented. A first device charges a storage capacitor to a voltage proportional to the peak voltage of an incoming signal. A second device coupled to the first device in a feedback configuration further charges the storage capacitor with a charging current in addition to the charging current provided by the first device for more rapidly charging the storage capacitor to said voltage proportional to the peak voltage of a low duty cycle short duration incoming pulse. This detector is particularly applicable to a video system having peak luminance detection requirements.

Abstract: A television receiver receives a scrambled television signal of the suppressed sync pulse type. The sync pulse is restored by a decoder which provides a sync restored video signal to video signal processing circuits of the receiver, and to automatic gain control circuits of the receiver via an interface network. The interface network develops a gain control signal with a magnitude related to the magnitude of the restored sync pulse. The gain control signal is coupled to both sound and video gain control circuits for augmenting normal automatic gain control action with respect to sound and video signals.

Abstract: The IF section of a television receiver includes an amplifier having an input terminal for receiving an IF signal and an output terminal at which an amplified version of the IF signal is developed and a SAW filter having two input terminals, one of which is connected to AC signal ground, for receiving the amplified IF signal and an output terminal for providing a modified IF signal having a bandpass characteristic determined by the SAW filter. An impedance transformation network is coupled between the output terminal of the amplifier and the input terminal of the SAW filter for increasing the effective load impedance of the amplifier and for decreasing the output impedance of the drive arrangement. The former aspect of the impedance transformation network allows a transistor with lower current supplying capabilities to be employed. The latter aspect of the impedance transformation network tends to reduce undesired voltages developed in response to reflections between the transducers of the SAW filter.