Filter Modulator ver2

Board information - version 2

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

Temporary photo:

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, so DO NOT FIT L10.