Abstract: A waveform display apparatus that can display a waveform in a desired position even when an internal reference mode is switched to an external reference mode. The internal and external reference modes are switched with a reference select button 60. A user operates a phase adjustment knob 64 while watching a display 54 to adjust a phase relationship between an external reference video signal and a video signal under test. When the phase relationship becomes proper an offset save button 66 is pressed to store the phase offset at the situation in a memory 56. A CPU 30 reads out the phase offset according to needs such as the waveform display apparatus is turned on, etc. to control a phase adjustment circuit 44 for adjusting the phase relationship between the external reference video signal and the video signal under test.

Abstract: A waveform display apparatus that can display a waveform in a desired position even when an internal reference mode is switched to an external reference mode. The internal and external reference modes are switched with a reference select button 60. A user operates a phase adjustment knob 64 while watching a display 54 to adjust a phase relationship between an external reference video signal and a video signal under test. When the phase relationship becomes proper an offset save button 66 is pressed to store the phase offset at the situation in a memory 56. A CPU 30 reads out the phase offset according to needs such as the waveform display apparatus is turned on, etc. to control a phase adjustment circuit 44 for adjusting the phase relationship between the external reference video signal and the video signal under test.

Abstract: CW lock is conducted with less manual operation. A first input 22 receives a black burst (BB) signal from a key TV station. A second input 30 receives a continuous wave (CW) signal having an accurate, known frequency. A phase adjust signal generator 24 generates a reset signal having a known phase relationship with regard to the key TV station BB signal. The reset signal is used as a phase adjust signal. A PLL 32 receives the CW signal to provide clock. A counter 34 receives the clock and provides a frame pulse signal for synchronizing the key and local TV signals at a local TV station wherein the BB signal of the local station may be derived from the frame pulse signal. The counter 34 uses the reset signal to adjust the phase relationship between the key TV station BB signal and the frame pulse to a desired phase relationship based upon the key TV station BB signal.

Abstract: CW lock is conducted with less manual operation. A first input 22 receives a black burst (BB) signal from a key TV station. A second input 30 receives a continuous wave (CW) signal having an accurate, known frequency. A phase adjust signal generator 24 generates a reset signal having a known phase relationship with regard to the key TV station BB signal. The reset signal is used as a phase adjust signal. A PLL 32 receives the CW signal to provide clock. A counter 34 receives the clock and provides a frame pulse signal for synchronizing the key and local TV signals at a local TV station wherein the BB signal of the local station may be derived from the frame pulse signal. The counter 34 uses the reset signal to adjust the phase relationship between the key TV station BB signal and the frame pulse to a desired phase relationship based upon the key TV station BB signal.