A Portable Radio Direction Finder for 90 to 7, 700 Kilocycles #271183

The receiving set used in this direction finder is a superheterodyne which employs a standard Signal Corps amplifier. The tuning con trols have been reduced to a single one by mounting the main tuning condenser and the heterodyne generator tuning condenser on the same shaft. The shaft also carries a cam which operates an auxiliary variable condenser which maintains a constant frequency difference kc m) between the heterodyne frequency and the incoming frequency. The receiving set is shown in Figures 4 and 5. Figure 6 gives the circuit diagram, and Figure 7 gives it in simplified form.