SIMPLE VLF RECEIVER CIRCUIT PDF

To view those files, you need a PDF viewer such as SumatraPDF (Windows): SID Receiver v1.1 power supply schematics The schematics for the SID receiver as well as the bill of material is available here: The design has been highly inspired from the SID monitor of the Stanford Solar Center. The interface between the MAX187 and the computer is done though an USB port. This level is averaged (default time constant around 1 minute) to produce a signal strength value.ДC offset can be applied to the signal strength value, before further amplification in the output amplifier section (selectable gains of x3.25, x4 and x10).ДЇinally, the analog to digital conversion is performed by the 12-bits ADC MAX187. Then, a full-wave rectifier and peak detector is used as a linear detector converting the RMS value of the VLF station to a DC voltage level. A buffer provides an optional carrier output with a 50ГЋВ© impedance. It has a gain adjustable between 0 and 10. The following section is the RF post amplifier. The MAC275 is configured as a bandpass filter center frequency, gain and Q are adjusted by resistors. The MAX275 is a continuous-time 4th-order active filter. The signal is then filtered in the tuning section. The RF pre-amplifier section is built around one non-inverting amplifier with a gain of 21 and two inverting amplifier stages with gains adjustable between 0 and 25. The signal from the antenna (usually a loop antenna) is filtered out to limit the signals to the frequencies of interest in the VLF and lower-LF frequency range. The basic principle of the SID receiver is to measure the amplitude of a VLF station and to convert it to digital data.

Simple vlf receiver circuit