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 is the receiver circuit for the previous remote control published in the same Radio...
This circuit, for signals up to 1 MHz, is based on an RCA operational amplifier. The circuit was...
This frequency shift modulation circuit was found in the November 1994 issue of Electronics Now...