Abstract: A biostimulator delivery system having a tether cable, is described. A connector can be mounted on the tether cable to connect to a biostimulator. The connector can be a protuberance that lodges within the biostimulator, or a threaded connector that screws into the biostimulator. The tether cable has a stranded cable configuration, including several strands extending about a core strand in a helical direction. The stranded cable structure resists breaking under bending stresses typically seen during a tether mode used during delivery of the biostimulator. The tether cable reliably secures the biostimulator to the delivery system in the tether mode. Other embodiments are also described and claimed.