video comparator circuits

heres some schematics for the comparators. type 1 is used for sync processing. feed any h or v sync signal in, patch the outputs to the sync input jacks on some vcos, and twiddle the knobs and flick the switch till you get sync lock. easy. no pcb layout for these as i built them on stripboard.

type 2 grounds the negative side of the threshold pot, and takes the +V side through a switching jack, so you can insert an external signal to be used as the threshold voltage. useful for making a pwm squarewave or various other patches. both circuits have hysteresis controls to clean up the output a bit.

both of the above circuits are run from plus and minus 12 volts. the 3k9 pull up resistor means the output swings rail to rail, so it can trigger either of the 2 vco designs (one syncs on a -12 volt spike, the other on a +12) with ease.
cheers
s/p