Editing Signal generator (section)

==History==
In June 1928, the [[General Radio]] 403 was the first commercial signal generator ever marketed. It supported a frequency range of 500&nbsp;Hz to 1.5&nbsp;MHz.<ref>{{cite web |last1=Burke |first1=Charles |title=The Standard-Signal Method of Measuring Receiver Characteristics |url=https://www.ietlabs.com/pdf/GR_Experimenters/1930/GenRad_Experimenter_March_1930.pdf |publisher=[[General Radio]] |archive-url=https://web.archive.org/web/20181218110326/https://www.ietlabs.com/pdf/GR_Experimenters/1930/GenRad_Experimenter_March_1930.pdf |archive-date=December 18, 2018 |date=March 1930 |quote=Experimenter - Issue Vol. IV, No. 10 |url-status=live}}</ref>  Also, in April 1929, the first commercial frequency standard was marketed by General Radio with a frequency of 50&nbsp;KHz.<ref>{{cite web |last1=Thiessen |first1=Arthur |title=A History of the General Radio Company 1915-1965 |url=http://www.ietlabs.com/pdf/GR_books/AET%20GR%20History%201915%20to%201965.PDF |publisher=[[General Radio]] |archive-url=https://web.archive.org/web/20181218051337/http://www.ietlabs.com/pdf/GR_books/AET%20GR%20History%201915%20to%201965.PDF |archive-date=December 18, 2018 |date=1965 |url-status=live}}</ref>