Filter Modulator ver2

Board information - version 2

PCBs supplied after 28 February 2017 are Version 2 and include the modifications to improve spectral perfomance.

The Version 2 the parts list and schematics are available for download:

• xls parts list file - includes the extra components for V2

• Board layout

• Block diagram

• Block Diagram with IC Numbers

• Circuit schematic - part 1

• Circuit schematic - part 2

• Circuit schematic - part 3

Although the board includes the options to fit a switching voltage regulator (an R78E5), the regulator introduces spurs at -50dB on the output spectrum , so is not the recommended option. Fitting L10 (after cutting the track beneath it) does not suppress the spurs and introduces voltage drop, which upsets the modulator balance.