11. One of the first amateur superheterodyne receivers , built in 1920 even before Armstrong published his paper. 12. By the mid-1930s, commercial production of TRF receivers was largely replaced by superheterodyne receivers . 13. Radar detectors are built around a superheterodyne receiver , which has a local oscillator that radiates slightly. 14. Akrabbim is correct and the effect is described at Superheterodyne receiver # Image frequency ( fimage ). 15. The intent was to develop an alternative receiver circuit that required fewer tuned circuits than the superheterodyne receiver . 16. Crystal oscillator superheterodyne receivers with better selectivity and stability made control equipment more capable and at lower cost. 17. Each student built a superheterodyne receiver , and fault-finding was taught using systematic signal-tracing. 18. Consequently, there can be mutual interference in the operation of two or more superheterodyne receivers in close proximity. 19. The receiver part is generally divided into two types : the super-regenerative receiver and the superheterodyne receiver . 20. Historically the term " aliasing " evolved from radio engineering because of the action of superheterodyne receivers .
