This repo will contain an arduino sketch and KiCad files for a pcb. The pcb shall output stable 25 and 40 MHz sine, derived from a 10MHz OCXO or external GPSDO 10MHz
The arduino sketch is licensed under the terms of GNU General Public License.
https://www.gnu.org/licenses/#GPL
Files in the kicad directory are 'Open Source' under the terms of the definition for Open Source Hardware Association.
http://www.oshwa.org/definition/
A first sketch I got from Wolfram DF7KB, after he made some experiments to reduce phase noise. The genious trick was to rely on integer operations only in the synthesizer. It was derived from the examples found in etherkit libraries.
The schema of the board is easy:
The routing of the pcb was done by hand:
Have fun!
sl0