Passive-detector receiver keeps you informed, entertained during flights

摘要

Faa (Federal Aviation Administration) regulations generally forbid the use of receivers onboard commercial aircraft because a superheterodyne receiver's local oscillator can radiate signals that could interfere with aircraft communication and navigation systems. The crystal radio in Figure 1 directly detects nearby AM signals in the very-high-frequency aircraft band, 118 to 137 MHz, and thus cannot interfere with aircraft equipment. Communications between the pilot and the flight controllers are brief and infrequent, and listening to the aircraft band as a passenger can get boring. However, the circuit in this Design Idea improves on an earlier passive aircraft-band receiver by allowing you to enjoy an aircraft's in-flight-entertainment system while monitoring pilot-to-ground communications (Reference 1).