Can anyone show anywhere a EMP gun or weapon or pulse has been tested or used?
http://www.businessinsider.com/first-us-test-emp-weapon-2016-11
Operation Fishbowl. The Russians did their research first on this.
If you detonate a nuke at N45, There are auroral effects you can see very clearly at S45.
They are still not sure why this is.
Bottom line: A nuke shakes electrons out of the ionosphere. Because of the cuvature, there is a lensing/focusing effect that sends those electrons in three waves down to Earth. Unless your stuff is in a faraday box, the effect is no bueno. Enough to melt the windings of a motor or generator or overload isolation transformers.
Best way to think about it - like shaking all the snow off the roof and trees all at the same split second.