I have gone ahead and appropriately re-tagged all 18 questions. The tag is now empty. Could a mod please delete it and set this meta-post status-completed?
Future questions should use radio-communication, radio-astronomy, or radio-telescope as appropriate.
I've gone ahead and adjusted tagging on:
Was it a "Soviet military satellite not in any of the catalogs?"
Is the recently discovered VLF-induced radiation barrier in any way important or useful?
Everything else stated at the moment seems okay to me.
I can agree it with the condition that it does not destroy content.
All the removed radio tags should be replaced by a more specific one (radio-astronomy, radio-communication, and so on). So it is not deletion, but improvement (more specific tag -> more information). Or any edit is okay, if the total information content (measured in bits) grows and does ...