You tell here you have found a way to improve your calf's by jumping rope. What you do not realize is the most obvious thing: that what you do while jumping rope, is using your calf's to do what they are meant to do. In other words what ever you have done previously, haven't work that well, so it is quite obvious that your training methods has been faulty. It is more than common mistake, it is more like industry standard to use faulty training methods. I just point out the fact about the matter 
This^^^
Training the calf muscle is a lot like squeezing a rubber ball. There is no easily felt "endpoint" like there is in a bench press or curl. Many people, myself included, spend hours doing crappy reps. When I changed to slow and deliberate contractions, with quite a bit lighter weight that I used to use, they started to grow. I find doing them on a leg press machine to be a lot easier to concentrate on than the standing calf raise btw.
