Burkhard Kainka (226)

1-08-2022 | The circuit is very simple: an ultra-bright green LED, two 10-MΩ resistors, two 100-nF ceramic capacitors and a push-button switch. When you...

1-08-2022 | This two-transistor circuit forms a simple square-wave generator with a frequency of about 5 kHz. The connection to the LED passes over mult...

1-08-2022 | The two-finger organ is a musical instrument for adepts and is just about as difficult to play as a Theremin.

1-07-2022 | What do capacitors have in common with wires in water or fingers touching metallic surfaces? Quite a lot, as the author discovered with his...

19-05-2022 | What do capacitors have in common with wires in water or fingers touching metallic surfaces? Quite a lot. You can use skin impedance for a v...

17-12-2020 | This very private AM station enables you to receive the good old BBC by Internet radio and rebroadcast it inductively on medium wave. Just l...

1-07-2020 | Anyone who designs, builds, or repairs radio receivers can make good use of a small AM signal generator. With a suitable signal waveform, yo...

1-07-2020 | You can buy Hall sensors, but making them is far more interesting (and satisfying)! According to the theory, the crucial thing is to use a t...

1-07-2020 | In days gone by a radio amateur always had a dip meter close to hand in his ‘shack’. Now that people can afford oscilloscopes, the poor old...

1-07-2020 | You occasionally see advertising signs in shops with a blinking LED that seems to blink forever while operating from a single battery cell....