QTH.com utilizes the Apache web server platform.
As a general rule, most files (including PHP files) will need 644 permissions (rw-r--r--) and folders will need 755 permissions (rwxr-xr-x).
One exception is for Perl files, which need 755 permissions (rwxr-xr-x).
The public_html folder normally has 750 permissions (rwxr-x---) and is owned by your username but with the group set to nobody (username.nobody)
As always, if you need help, feel free to contact QTH.com Support.