converting manpages to postscript

[Dru]

I'm trying to convert a manpage to postscript and have tried these 3
variants:

groff -Tps -mandoc /usr/share/man/man1/ls.1.gz > ls.ps
groff -Tps -mdoc /usr/share/man/man1/ls.1.gz > ls.ps
groff -Tps -man /usr/share/man/man1/ls.1.gz > ls.ps

The file command always shows this:

file ls.ps
ls.ps: Postscript document text conforming at level 3.0

But the resulting printout is hieroglyphics.

What am I doing wrong?

Dru