AM radios are relatively simple devices, and building one is a good way to start exploring the world of radio communications. [GreatScott] does exactly this in the video after the break, building b… ...

In 1901, Marconi sent a signal across the Atlantic using the recently discovered radio waves. It paved the way for today's complex wireless communications systems such as satellites and mobile phones.

For the first time, researchers have used a laser as a radio transmitter and receiver, paving the way for towards ultra-high-speed Wi-Fi and new types of hybrid electronic-photonic devices.

The transmitter consumes almost no power, but the receiver consumes substantial power, up to 2 watts. This is similar to receivers in other ultra-low-power communications systems.

It’s a 40 meter (7 MHz) QRP or low power transceiver in which the transmitter is a simple crystal oscillator and the receiver is an equally simple regenerative design.

Researchers have developed a new analog photonic correlator that can be used to locate an object transmitting a radio signal. They demonstrated its ability to identify the location of a radio ...

Object Details maker Cardwell Manufacturing Co. Description (Brief) Marked: "Signal Crops U.S. Army / Radio Transmitter Type BC-114 / Used with Radio Tel & Tel Set / Type SCR-134 / Designed at Radio ...