w4jle wrote:

" Does a tuner change the SWR of an antenna? Or
does it simply transform an impedence to one that makes the transmitter
happy? Will the maximum field strength coincide with 1:1 SWR at the tuner in
all cases?"

1. A tuner doesn't change the SWR of an antenna. It will change
the SWR of the system to something the transmitter 'likes'.
2. In all cases? Probably not. In 'most' cases? A definite
maybe.
'Doc