Note
QST, Nov 1933, p. 83.
Service magazine, Feb 1935, p. 89. (new and improved)
QST, Jan 1937, p. 102. ("10,000 hams can't be wrong")
QST, Jun 1945, p. 95. (ad says D-104 introduced in 1933)
QST, Nov 1965, p. 159.
QST, May 1972, p. 147.
QST, Jul 1975, p. 157.
QST, Oct 1975, p. 157. (golden eagle model)
QST, Jun 1976, p. 139. (silver eagle model. Interesting in that it shows the mic being used with CB equipment)
QST, Oct 1977, p. 120.
An ad in Service magazine, Feb 1935, p. 89, announced a "new and improved" microphone "supassing the original D-104 in quality of response" but provided no specifics.
