We found this configuration in a 1990 Poptronics. The circuit can be powered by voltages between 6 and 15 V, changing the resistors in series with the LED. The frequency is set at R7.
This small transmitter with 2 transistors can reach several hundred meters using a 30 to 70 cm...
Although modern integrated versions exist, this 1995 circuit shows a discreet solution with common...
This circuit from Ferranti was released in 1969. It makes use of the company's transistors that admit...