A method in a television receiver receiving interlaced analog modulated television signals includes: detecting an inactive video period in the television signal between two successive video display fields; generating a synchronization signal indicative of the detected inactive video period; and in response to the synchronization signal, performing measurement and adjustment operations on analog circuitry of the television receiver. In another embodiment, a method in a television receiver receiving interlaced analog modulated television signals includes: detecting an inactive video period between two successive video display fields using a not-fully-demodulated intermediate frequency (IF) signal; and generating a synchronization signal indicative of the detected inactive video period. In another embodiment, a vertical field detection circuit in a television receiver includes a vertical field detector circuit configured to detect an inactive video period in the television signal between two successive video display fields using a not-fully-demodulated intermediate frequency (IF) signal.