I remember candidates matches 1974 and 1977, and final candidates duel in 1978 in Belgrade between Korchnoi ans Spassky. And Baguio duel between Karpov and Korchnoi.
At the time there were only 2 state TV channels and 1 regional.
"Chess commentary" was aired on I channel late at night after second TV news, often after 23.00 or even after midnight if there were some longer films before last TV Diary.
Edit - I forgot to add, that I watched those late commentaries, and it was live game fr me coz I didn't know the result, and it was one game chosen for commenting, and the results of other matches were reat AT THE END of the commenrary! Commentators were Gligoric, Marovic, Matanovic etc...
And I had an impression we all were wondering what results were, I had to wait til midnight to find out that for example Korchnoi is lading 3-0 against Polugaevsky, or to read in morning paper on sport pages (*at the time I used to go to bed in proper time!).
I still remember how I eagerly followed long postponed match between Korchnoi and Kasparov in 1983. At the time there were extreme electric power shortage in Yugoslavia, great crisis, and I came from the school afternoon, late afternoon, we had no power, I grabbed daily paper, I went out on the terrace in my coat, it was winter was it?, and at the time Korchoi was in the lead after he won very first game, and by inertia I still was rooting for him, old bugger, and I brought sport page under the street light, and with great effort, like Edgar Allan Poe's Gordon Pym I slowly read "out of the corner of my eye" - Kasparov equalized. Dang!
Well, once chess was popular, I could hear pensionists in the park in heated arguing over the Korchnoi's matches, often in connection with their political affiliations (*ha ha), and I remember so well, I went in the overcrowded chess club of my youth, packed with people waiting for next blitz tournament with great Garde clocks (with smaal wooden laths so as to protect the clock from very very heavy punches!), the room were filled with smoke (*at the time smoking was still allowed much to my annoyance and despair), and someone brought the news Korchnoi resigned sixth game against Karpov!, yeah, it was 1978, and murmur and sigh of disappointment spread over the chess club room.
And never again this club (and any other for that respect)= was full again as in 1972, as in 1978. And "Chess comments" gradually disappeared from state TV, last sign of life of chess programme was in late 1980's during Belgrade October tournaments, one of which was won by Ljubojevic, and we could see there Kasparov and Short and Ivanchuk on their peak.
Now, while I was driving in a cab, recently on round of Belgrade Trophy, I spoke with a cab driver about chess, we agreed that no one knew of Carlsen vs Karyiakin match. No fever, no excitement, no fans for one or the another, no one really cared.