Years ago I built most of a Sierra on a FAR Circuits board, substituting an FCC-2 DDS for the oscillator and pre-mixer. I did this to showcase the capabilities of the then-new FCC-2, designed by my friend Bob Okas (now SK). The FCC-2 worked very well on 80 and 40 meters, but the spurs were less than 40 dB down on 30 and 20. I put the project aside mainly because I didn¡¯t know how to tame the second harmonic, only 37 dB down on 40, and worse on 80. Well, 15 years later I¡¯m pretty sure the second harmonic can be tamed within the confines of the plug-in module and I¡¯ll look forward to getting to it one of these days. If anybody has had better luck with second harmonic suppression, please let me know how you did it. The photo shows my Sierra with the FCC-2 inside a brass shield. The boards are stacked to make the front panel more compact.
