This preamplifier for the 6 or 2-meter range was obtained from an American documentation from the 1980s. FETs can be modern equivalents and no information about the coils is given.
This circuit causes the relay to be energized when the input voltage exceeds the voltage value of...
The maximum frequency of this circuit is 500 kHz. We found it in a documentation for radio...
The mains cables work as antennas. We can take advantage of them with this circuit that consists of a...