This is a Sabre Edit video editor by Grass Valley Group. Posted by u/iaakki.
KBD.news Published May 7, 2022
Creators! Feel free to tip me off about your keyboard related projects to bring them to 140K readers.
Not much info on this monster. Color-coded keycaps, big-ass enter, four rotary encoders, interesting clusters. Alphas as sublegends is something I rarely see. Pre-1984-ish arrow cluster but Cherry black switches under the hood so it's apparently post '84.
Grass Valley are a pro video company and this is one of the custom keyboards that they sell/sold(?) for video editing. The wheel on the right is used to jog/shuttle through video clips.
Indeed, Grass Valley seems to be a big name in the field of live broadcasting, but I couldn't find this particular keyboard on their site so this one may be an earlier, discontinued model.
Grass Valley Group Sabre Edit
Grass Valley is the leading technology provider for the live media and entertainment market. We work with 90% of the world's major media brands, powering their media centers, mobile production units, 24-hour newsrooms, and sports streaming platforms. As the number one trusted partner in media technology, we enable content owners and service providers to create and deliver compelling live experiences in the most efficient way. (source)
I reached out to the company for more info and will update this post if I get any feedback.
EDIT
So Pascal from Grass Valley's Eastern European branch got back to me with this reply:
I am since 22 years in the group, but never saw this HW before. It is probably a quarter century old. This gear is not in use any longer; it is even not registered in our EoP-End of Production data base any longer.