We found this preamplifier for the 10 and 11-meter range in an old documentation for radio amateurs. The integrated circuit used is uncommon today.
This circuit was published in an English magazine from 1980. The magazine no longer exists, but...
Found in a 1990s Motorola documentation, this high voltage circuit uses a PUT that is not a common...
This proximity sensor was found in a 90s Popular Electronics. The base is a PLL567 that operates...