Does anyone here use a 4-square antenna on 80 metres? How many
radials are recommended on each of the verticals?

I'm in the middle of building one. I'm planning on about 50 radials
per vertical. To save wire I will probably shorten the radials "inside"
the array and connect them to bus wires.

The radial-laying sure is taking a lot more time than putting up the
verticals :0

Tor
N4OGW