The radio should only have one fuse on it; in line to the ignition wire and it should be a 3 or even 5 amp.
Assuming that all things are equal, you should be able to mangle the antenna all you want without any effect on the radio or electrical. A cordless drill makes no charge to damage a radio that I can think of.
I would guess that the cordless driver work is unrelated to the inoperative radio.
A one amp fuse is too light and that is likely the cause. Plus, you should only have one inline fuse.
