This interference rejection circuit for telegraphy was found in a 1980s documentation for radio amateurs. The integrated circuits used are common today.
This high sensitivity receiver of 30 nW was found in documentation from the 1980s. Integrated...
This amplifier was found in a 70s documentation. The product gain x bandwidth is 350 MHz. The...
To control direct current loads, under voltages between 12 and 200 V, and currents up to 3 A, we...