The following is a classic example of the Signal Corps. adopting a proven French design and evolving it into a widely produced piece of American equipment.
This is the French A-1 receiver.
This particular unit was probably sent to the U.S. for study. It
was obtained from the estate of a man who served the
Quartermaster Corps. in Washington D.C. during the First World
War.
Note the removable, calibrated buzzer type wavemeter in the lid.
This is the American AR 4 (BC-14) receiver. Note the marked similarity to the A-1. The A-1's calibrated wavemeter was replaced by a standard buzzer and modest calibration chart. A companion wavemeter was produced for finer calibration. The main detector was slightly Americanized, the French type of phone plug was replaced with a standard American plug and a special shorting plug was provided for use when a separate detector unit was needed.
The AR 4 was produced by Western Electric and Liberty Electric in very limited quantities. This set is especially rare today.
This is the American BC-14A receiver. Again note the similarity to the A-1 and the AR 4. The buzzer has been moved to the panel, the detector has been made non-removable, emergency headphone terminals were added and the calibration chart has been enlarged and hand calibrated.
The BC-14A was manufactured by at least four companies- deForest, Liberty Electric, Wireless Specialty and General Radio. Judging by the number of these sets in existence today, it was made in large quantity - many (or most) of which were never shipped overseas.
