Three Channel Jones Colorizer

Though I always intended to build a colorizer, boards were in short supply, and I managed fine colorizing by patching subcarrier into video rate VC inputs of various modules - mostly my keyers. This was a lean approach. On a recent trip to Owego Dave Jones revealed he had 3 channel boards on a shelf along with the last RGB board. He generously gave them to me, as long as I actually built the colorizer. Considering Dave's designing a new and improved Eurorack version of the colorizer, the value for these older boards is limited, especially considering the large form factor.

Completion of Modification of Jones Keyer

Images of completion of modifying Jones keyer. I replaced the comparator and associated logic circuit with a differential amplifier - one of my last MC-1445s. I struggled with getting as much gain out of this circuit as I could. The gain is still not high enough but it's a start. A tricky part was the logic for on off and normal reverse. Thanks to Dave for help.