Quote:
Originally Posted by Kevin Kuehn
Is it not possible to have the horizontal oscillator adjusted wrong and still be locked, but out of phase?
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There are two things happening.
1) The oscillator is locked. The phase locked loop is basically functioning. The free running horizontal frequency may be off center, but it is within the pull-in range of the loop.
2) It is locked at the wrong phase and is stable at the wrong phase. This should not happen whether the free-running horizontal frequency is correct or not.
Note that when the loop is locked, adjusting the free-running frequency +/- will rock the phase back and forth a bit to generate the correction voltage that keeps the locked frequency correct. This effect can be seen when the circuit locks at the correct phase as normal or the incorrect phase as shown here.
Something is making the control voltage out of the phase detector correct when the phase is 180 degrees from normal.