Abstract: A cathode ray tube socket assembly incorporating controlled, or tuned, spark gaps coupling the high voltage focus grid system to ground to prevent television receiver damage caused by CRT arc-over. Incorporated within the CRT socket assembly are a high voltage spark gap connected to the CRT's G.sub.4 focusing grid and a lower voltage spark gap connected to G.sub.3 focusing grids, each spark gap including ridged sections defining an inter-electrode aperture. By varying the size of the inter-electrode aperture and its distance from each electrode, the spark gap's arc-over threshold voltage and breakdown voltage range from initial arc-over to continuous corona discharge may be precisely controlled.

Abstract: In a television receiver, an automatic phase control includes a phase detector which generates a control signal passed by a bandpass filter to a horizontal oscillator in order to synchronize locally generated horizontal pulses with the received horizontal sync pulses. A keyed AGC circuit in response to increased received signal strength decreases the gain of the RF and IF amplifying stages. When the received signal strength reaches a preselected level, as occurs during off-the-air signal reception, the AGC signal actuates a transistor switch which widens the passband of the filter in order to increase the ability to lock onto irregular sync signals.