G4HUP Direct Frequency Synthesis

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These pages are devoted to my recent project - a direct frequency synthesiser, to provide a GPS locked output for transverter local oscillators. This replaces the crystal oscillator with a signal source of similar quality, but without the drift associated with temperature variations seen with crystal LO's. The output is locked precisely to the input frequency, so no more annoying efforts trying to get the XO exactly on frequency!



DFS Presentations and Papers

For an outline of the DFS process see August 2007 Midwest VHF-UHF Society Presentation

Click here for October 2007 MUD DFS presentation and here for the Proceedings paper

Here is the November 2007 Martlesham Microwave Round Table paper.

Click here for the 124.5MHZ DFS presentation given at Munich Amateurfunktagung 2008. Also, click here for Fig 3 which was omitted from the Proccedings by accident

The above presentation refers to tables from the proceedings article - click here

Presentation from Dayton Hamvention 2008 includes first detail of Issue 2 PCB's - click here.


Issue 2 PCB Documentation click here.

For DFS Issue 1 documentation see here. This page includes design guides and worksheets, filter and frequency schema information, construction notes, Technical manual and bill of materials etc.

For availability of PCB's, boxes and part kits click here.

Page created 17 Oct 2007

Page last updated 27 May 2008