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.
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.
I am wrapping up a week at Signal Culture doing a tool residency. Signal Culture is a special place, thank you Jason, Debra and Hank for making this happen and keeping it going. David Jones has been really genrous with his time, in part the residency was an opportunity to spend time with David and Hank Rudolph.
CMOS analog multiplexers were frequently used at the ETC for various purposes. Here I thought I would present a circuit I borrowed from a Dave Jones design, and slightly modified it, to build a black burst generator.
While working for the Experimental Television Center I built the first four Jones Frame Buffers with David. Pictured here is the one I built for myself. The first few buffers where built into the same card racks that were ubiquitous at the ETC at that time, later David rewired most of the buffers into newer larger boxes. This one might be the only one that stayed in the old rack.
These are my first experiments recorded in Jan 2008 on a Rutt/Etra scan processor.
This Jones video synthesizer is comprised nearly exclusively of Jones designs. This synth includes a video patch panel made of an inset piece of hardwood with mini-jacks carrying 2vpp differential video (subsequent modules use Plexiglas). The advantages of this standard is that it limits crosstalk and noise, and making a video signal negative one simply uses a cable that flips the polarity of the wires. It was thought for a time that this system would be embraced by Jones in general, however no synthesizer at the ETC uses the format (the system at the ETC patches standard single ended 1v video through a slide matrix). Using differential video was a great idea but as an unusual standard it only made sense for patching within the panels of multi module synthesizers, and other than a few of the Tuesday afternoon participants, it was an idea that was not really implemented. Unfortunately Jones has yet to manufactured multi module synths as Hearn did.
This was an early Dave Jones keyer. Rich Brewster documented and built it. We referred to this as the black box keyer because it was in a black box. This keyer moved around a bit, at times it was at the center, at times it was at Ralph's studio. I first used this keyer as a student working at the ETC in the converted photo lab studio (at that point the Center was still on Court Street in Binghamton). Years later when I was working for the TV center I lobbied to install it back into the ETC studio.