The LED.Rx is used to receive and demodulate light from the LED.laser or LED.white, which has been modulated using the LED.modulator. The light is collected by a phototransistor on the front of the unit, which is white for easy aiming of the laser beam over greater distances. A BNC socket at the back outputs the demodulated signal. When connected to an audio amplifier, the signal carried by the laser can be heard. Alternatively, the signal can be observed on an oscilloscope. The LED.Rx responds to the 1MHz signal produced by the LED.modulator, and by comparing the source and received signals on a dual-trace oscilloscope, it is possible to measure the speed of light. It is housed in a convenient flat-bottomed cylindrical housing for work on the bench, and a boss on the back allows mounting on a retort rod. Note: a BNC plug-to-plug lead is required for connection to an oscilloscope. A plug-top power supply and an experiment guide are included. The LED.white, LED.laser and LED.Modulator are all available to purchase separately.
