Valjoux Cal. 7730 is a cam-switching chronograph movement based on the Venus 188. After Valjoux acquired Venus in 1966, the company took the affordable Venus Cal. 188 architecture and launched a new Valjoux-branded movement. The only notable change was the use of a mobile stud carrier. Cal. 7730 was produced from 1966 through 1973 with a reported 175,000 examples produced. It was replaced by the redesigned Valjoux 7733 starting in 1969.
Cal. 7731 is essentially the same movement with a new balance cock.