This is the receiver for the previous transmitter. The signal consists of digital pulses with a compatible TTL or CMOS output. The integrated circuit is a 4093 and a photodiode of any type.
If the battery is good, the LED flashes. This simple tester uses an LM3909 integrated circuit. We found...
This circuit was found in a 1926 German publication. It is a crystal or galena (D) receiver. The...
In the figure we have a typical configuration with operational, which can be different from the...