OK if done a ton of research into this subject and its very clear that a 20 kiloton weapon detonated between 80 and 120 miles up would not cause the extream damage most people like to talk about. It would take a megaton clas weapon to knock out everything.

A kiloton class weapon would more than likely damage the electrical grid and most likely anything plugged into a wall outlet. It would not make all vehicles come to a screaming halt, planes would not fall out of the sky and any hand held items should be fine. Generators will work as lomg as they are not connected to your house circuit. This due to the free electrons racing from the sky trying to fing ground. Theybwill passaround anthing that is not at a better ground potential the well, the ground. The only real tests go back to the 60's and the megaton class weapons are the ones that showed noticable effects.