tuner vs receiving system

tuner and receiving system both are nouns.

Word	Noun	Adjective	Verb	Adverb
tuner	Yes	No	No	No
receiving system	Yes	No	No	No

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

tuner: an electronic receiver that detects and demodulates and amplifies transmitted signals
receiving system: set that receives radio or tv signals

Other hypernyms of tuner include receiver.

tuner (noun)	receiving system (noun)
an electronic receiver that detects and demodulates and amplifies transmitted signals	set that receives radio or tv signals
someone who tunes a musical instrument