superhet vs receiving set

superhet and receiving set both are nouns.

Word	Noun	Adjective	Verb	Adverb
superhet	Yes	No	No	No
receiving set	Yes	No	No	No

As nouns, receiving set is a hypernym of superhet; that is, receiving set is a word with a broader meaning than superhet:

superhet: a radio receiver that combines a locally generated frequency with the carrier frequency to produce a supersonic signal that is demodulated and amplified
receiving set: an electronic receiver that detects and demodulates and amplifies transmitted signals

Other hypernyms of superhet include radio, radio receiver, radio set, tuner, wireless.

superhet (noun)	receiving set (noun)
a radio receiver that combines a locally generated frequency with the carrier frequency to produce a supersonic signal that is demodulated and amplified	an electronic receiver that detects and demodulates and amplifies transmitted signals