Educate me on old style televisions

[Paul Sandhu]

23 separate STRs with about 75 televisions.  Every living room has a smart HDTV, every bedroom has an old style television.  There is cable and wifi at every address, it is a bundled service from Cox.  Right now I have 3 of them occupied.  The other 20 are sitting vacant.  I'm considering dropping Cox altogether and saving about $2500 a month.  I can get wifi from my city:

3 mbps is $25 a month for each address.

5 mbps is $40 a month for each address.

Every living room HDTV can do Netflix along with all the other streaming services.

I'd like for some channels to work in the bedrooms.  Do they even make antenna's for old style televisions that pick up free signals over the air?  Television is not that important to my renters.  They work 10-12 hours a day in a refinery.  When they get back to my places they just want to drink beer, cook dinner, and go to bed.