I haven't heard many station engineers talking about their "Grass Valley" TV transmitter. Depending on the vintage of the transmitter, they usually refer to it as a Thales, Thomson or even Comark, the original name of the Southwick, Mass. transmitter company. For awhile the transmitter company was called "Thomcast", but that name didn't seem to catch on.
"Comark" has changed its name again, this time from "Grass Valley" back to "Thomson". The name change is part of the process of Technicolor's divestiture of Grass Valley. Thomson Broadcast will operate as a standalone company separate from the base-band equipment company Thomson Video Networks.