Despite being from a 1969 publication, the transistors used have current equivalents such as BC548 and BC558. The circuit generates signals from 1 500 to 20 000 Hz and 4 scales.
We found this circuit in the February 1987 issue of Radio Electronics magazine. It is based on an...
This circuit is from an Argentine publication from the 1970s but can still be assembled with...
We found this circuit in a publication from the 90's. The circuit is used with sinusoidal...