Hi Mark,
Yes - this is possible with cloudHQ - you basically need to setup one-way sync from Evernote to a folder in some other cloud service (Dropbox, SkyDrive, Google Drive, or Box). So each time you add/modify a note, the note will be copied/exported.
And if you want only PDF attachments to be exported (not other attachment types or content of notes), please email us at support@cloudHQ.net - we have a special option for these kind of setup but you do need to contact support to enable that for your account.
And here is a short video how to setup continuous one-way sync / export o