Developments of the Heterodyne Receiver

The heterodyne receiver is defined and explained. Various arrangements for heterodyne reception are discussed. The use of the "regenerative" or oscillating audion is then considered. It is shown how any energy-amplifying relay can become an oscillation generator. Several instances are given. In connection with beat reception using the audion generator, it is stated that most satisfactory results are obtained in commercial service when it is used as a generator only, the detector being a rugged crystal combination. Examples of the extreme sensitiveness of the arrangements described are given.