You might recognize this as a page from TV Guide, circa 1970:
Now: which edition of TV Guide? The person who posted this on Facebook was from Philadelphia, but these channels don’t match up with Philly then or with Philly now. I resolved to find out without actually having to ask the guy.
The key, it turns out, is that NBC affiliate on channel 79. And while there were a few stations on 79, generally translators, only one fits with the rest of the scheme:
WVIT 30 Hartford once operated W79AI, a repeater in Torrington, Connecticut which is now abandoned.
And sure enough, 30 and 79 are carrying the same programs. So this is around Hartford, probably Springfield, and very likely Boston. The other NBC stations: WBZ-TV 4 Boston (now a CBS station); WATR-TV 20 Waterbury (now WCCT-TV, the CW); WWLP 22 Springfield; WRLP 32 Greenfield (now defunct).
I very likely would not have known any of this had I not been sojourning in central Massachusetts in the 1970s at the behest of Uncle Sam.