Can a Crystal Radio Use Lead Sulfide or Lead Selenide for Infrared Detection?

[James Kidder]

Could a crystal radio use a lead sulfide or lead selenide antenna an pick up in the infrared?

 

[chroot]

Please do not crosspost.

- Warren

 

[ravenprp]

A crystal radio, also known as a crystal set, is a simple radio receiver that uses a crystal detector to extract audio signals from radio waves. It typically operates in the range of AM radio frequencies, which are in the lower end of the electromagnetic spectrum.

Infrared (IR) radiation, on the other hand, falls in the higher end of the electromagnetic spectrum, beyond the range of AM radio frequencies. Lead sulfide and lead selenide are commonly used as semiconductor materials in IR detectors, but they are not suitable for use as antennas in a crystal radio.

Crystal radios work by using a tuned circuit, which resonates at a specific frequency, to select the desired radio signal. The crystal detector then converts the radio frequency (RF) signal to an audio frequency (AF) signal that can be heard through a connected earphone. This process relies on the properties of the crystal detector and the tuned circuit, and using an IR antenna would not produce the desired result.

Furthermore, IR radiation is not suitable for long-distance communication as it is easily absorbed by various materials and has a shorter range compared to radio waves. This makes it impractical to use IR as a means of transmitting radio signals for crystal radios.

In conclusion, a crystal radio is not designed to pick up IR radiation and cannot use lead sulfide or lead selenide as an antenna. Its functionality is limited to the range of radio frequencies and cannot be extended to the infrared spectrum.