Answer:
Yes, he married the former Marion MacInnis on 1 December 1923. Lots of information in Lawrence Lessing's biography of Armstrong about Marion, his courtship of her, and their marriage, which lasted until his suicide in early 1954. You can find the text of Lessing's book, Man of High Fidelity: Edwin Howard Armstrong, at the following URL:
http://books.google.com/books?id=rYAeAAAAIAAJ&q=lawrence+lessing&dq=lawrence+lessing&hl=en&ei=acukTPDiBszangfeg6WRAQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDcQ6AEwAg