This RIAA equalizer preamp was found in a 1990s schematic. The transistors are an old version of the BC549 that can be used as a replacement. Signal input and output cable must be shielded.
This circuit, which applies to configurations with triacs of the TIC series, was found in a...
This simple standing waveform (ROE or SWR) meter is used to adjust antenna matching with...
This circuit has a visual indication of activation and is suitable for people with hearing...