Zenith Radio Corporation

Warwick Electronics Inc.

John F Kulkens

Theodore M Ishihara

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.

Cathode ray tube socket with controlled spark gaps

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.

Growing community of inventors

Park Ridge, IL, United States of America

John F Kulkens