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 two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The...
This blocking oscillator was found in a publication from the 50's. The coils determine the...
The TPA3100D2 integrated circuit from Texas Instruments (www.ti.com) consists of an efficient...