Fm A special commemorative FM broadcast Saturday, June 11, at noon (EDT) will mark the 70th anniversary of Edwin H. Armstrong’s first public demonstration of wideband frequency modulation (FM). The transmission, from Experimental Station WA2XMN (remiscent of Armstrong’s W2XMN call sign) will be on Armstrong’s original 42.8 MHz frequency and will emanate from his landmark 400-foot Alpine Tower in NJ. I wonder if someone will podcast it. [via] Link.