This circuit is from a 60's documentation. The capacitance C1 can be between 20 pF and 0.01 uF depending on the generated frequency. Equivalent transistors may be employed.
This circuit causes an LED to flash at a frequency determined by the capacitor. The circuit is...
This simple 1-transistor receiver has speaker listening. We found it in an article published in...
The integrated circuit used is equivalent to the 555 and the transistor can be the BC558. R1 and...