We prefer that members post questions in the main forums (found at our main page, www.physicsforums.com), and not as a blog entry. Your question about analog signals is probably best asked in our Electrical Engineering area. You'll find a link to Electrical Engineering at the main forum page:
Once you find the Electrical Engineering area, simply click the "New Topic" button in order to post your question.
Physics Forums Mentor
p.s. More details on how and where to post a question can be found at the following link: