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.
Random pulses are produced by this multiple oscillator using unijuncion Transistors. The...
This watch was found in 2001 documentation. The watch is powered by 4 batteries. To save energy, the...
This circuit with the PA7601 was found in a 1967 Philco-Ford documentation. The circuit has a pass...