Abstract: In a television receiver having provision for a vertical detail enhancement signal, a circuit is provided for turning off the vertical detail enhancement without causing D.C. transients. A transistor circuit is provided having a feedback path between the collector and base electrodes which includes a capacitor and a diode. A switch actuated variable impedance is connected between a source of supply potential and the junction of the capacitor and diode. The capacitor is pre-charged when the switch is open such that when the switch is closed, to turn off the vertical detail enhancement signal, the junction point does not substantially change in D.C. level while the gain of the transistor amplifier is reduced to substantially reduce the amplitude of the enhancement signal.

Abstract: Apparatus is provided for suppressing radio frequency interference radiation at a circuit connection point. The apparatus includes a capacitor having first and second terminals, the first of which is coupled to a substantially planar plate of the capacitor. The first terminal is coupled to the circuit connection point, which may otherwise act as an RFI antenna. The second capacitor terminal is coupled to a point of reference potential for radio frequencies. The capacitor is oriented when mounted so that the planar plate opposes and is substantially parallel to a metallic surface which is at the radio frequency reference potential (e.g., ground). The capacitor suppresses RFI radiation from the circuit connection point by conducting a portion of the RFI energy at that point to the point of RFI reference potential by way of the first terminal, the body of the capacitor, and the second terminal.