- UPDATE - Phil was writing at the same time, sorry for the duplication (but Phil and I are essentially the same vintage and share many of the same experiences --- this I enjoy).
Coherent Communications was a company started by Ivan Kruglak who operated out of his home shop in Sylmar, California. I met Ivan first when he was the chief rental manager for Cinemobile. I don't know how long he held that position before going off on his own to design and build some amazing things. He did design the first working timecode slate much before Denecke started producing the Denecke line of timecode slates. Ivan's slate, developed along with Arriflex Camera, was part of a complete timecode system for utilizing timecode on film shoots. The slate itself was very heavy but contained very elaborate timecode generator with all sorts of functions, some of them to be used even in the edit room in post. It was definitely a "smart" slate but actually a little too smart (and too expensive) to actually get much usage in our industry. There were several other parts to the system, a module that was fitted to the Arri, another module to be used in transfer and the editing room.
Ivan built lots and lots of other things, one of them being the little lunch box mixer mentioned by Mike Filosa. I had one of those too and it had wonderful sound, tons of headroom, very few features or functions, only 4 inputs if I remember. What you have to remember about these times, the early '70's, 4 inputs was almost always enough for any job. Ivan built the Mini-Mic which was the precursor to the Tram and Sonotrim style microphone and was considerably smaller than the ubiquitous Sony ECM-50. Coherent had a line of wireless microphone sets, transmitter and receiver, packaged in a case which Ivan licensed from Audio, Ltd. Very similar form factor but built by Ivan in the U.S. They were marketed under the name Artech and I think there were about 3 people who used them. I was one of the people, I owned 4 of them, but the biggest user was Jim Webb who purchased about 16 of them to use on the Altman movies.
Lastly, Ivan did many modifications for me, first to my Sela and later to an Audio Developments Pico mixer that I used for a few years. He also built the custom box and configuration for 2 outboard processors that I use to use, in production, with my Sela. These were Allison Research modules, a Gain Brain and a Kepex, items which I knew even at the time should NEVER have been used in production (they really are designed to be used in post, but you knew that).
I haven't spoken to Ivan in years and years, I know he sold Coherent Communications and he also sold another business --- he was the sole US distributor for Fisher precision connectors (similar to Lemo) which turned out to be a million dollar business. Hopefully Ivan is retired and enjoying himself somewhere.