Found in a 1964 Electronic Design, this circuit makes use of FETs of the time. These transistors can be replaced by modern general-purpose types. The input resistance is 30 M.
The Variable Frequency Oscillator (VFO) shown in the figure can generate signals in a frequency...
This circuit was obtained from a 90s Radio Electronics. The integrated circuit used HAA11508 is not...
This circuit was found in a 1980s American schematic. Transistors can be modern equivalents. The...