Over the race track. I have seen it many times. Small Airport, too.

No one can tell what channel any TV is tuned to.
Ratings are based on Neilsen ratings, which are still generated by selected families recording in a ledger what they watch.

Many people are on systems which permit finer and more accurate measuring than the old broadcast and ledger system. Flip the channel and it is noted.

https://www.nielsen.com/us/en/solutions/measurement/television/

To measure TV audiences and derive our viewing metrics (i.e., ratings, reach, frequency), we use proprietary electronic measuring devices and software to capture what content, network or station viewers are watching on each TV and digital devices in the homes of our Nielsen Families. In total, we measure hundreds of networks, hundreds of stations, thousands of programs and millions of viewers. In the U.S., electronic measuring devices and millions of cable/satellite boxes are used to provide local market-level viewing behaviors, enabling the media marketplace to gain a granular view of TV audiences.

I receive over-the-air broadcasts on a home made Gray-Hoverman antenna -- some 1/4" aluminum rod bent to this guy's design. (I don't have to understand how it works, it just does). It's just as passive a receiver as my BUD (big ugly dish) for FTA (free to air) satellite feeds. No broadcaster or satellite provider knows when I change channels.

Comments on DU about changing channels when Agolf Twitler speaks, and thereby send a message to cable tv shows, caused me to check out how ratings are measured. Back in the late '70s, I once received and kept one of those Nielsen logs you mentioned. They're not quick enough for today's advertisers. It's a little spooky how many devices 'call home', now.

What NASCAR's Declining Popularity Can Teach Us About Responding to a Changing Market

I remember walking, hitching and riding a bike about 3 miles to a local dirt track when I was a kid. Don't think the races were sanctioned by any national body, but they were exciting.

I went once and never saw so many drunk, stars and bars wearing kooks in my life.

n/t