Abstract: The cable tensioner has a pair of elongated platforms mounted side-by-side on a base with each having drive and driven geared pulleys with geared idler pulleys therebetween arranged along the edge of the platform confronting the other platform. A geared endless belt encircles the pulleys on each platform and has a grooved exterior machined to match the cable being handled. The drive and driven pulleys are adjusted to tension the associated belts and the idler pulleys are pressed towards the idlers on the adjacent platform. The base is mounted to permit sideways motion plus pivoting, tilting and rising and falling as a unit.