The circuit transistors, found in a 1974 documentation, may be the BC548. The circuit is used in quadriphonic systems to combine signals.
This sample and hold circuit configuration was found in a manual from the 70s. The operational amplifiers...
This small MW transmitter emits its signals at a distance of a few tens of meters, depending on the...
Found in American documentation from the 90s, this circuit uses common FETs. It has a range drift...