As vacuum tubes were making CW practical, they were also making voice transmissions possible. Experimental broadcasts using radiotelephone—or just “phone” to hams—began as experiments by amateurs and some of the wireless telegraph companies, including Marconi and DeForest. In these early years of radio, just having a receiver to listen to the limited number of phone broadcasts was sufficient to be regarded as a radio amateur. The Marconi Wireless Telephone was demonstrated publicly for the first time on 12 June 1916.  … Continue reading →