Thanks, Mike, I will check out the dds-vfo list. Thanks especially to David Minkler for letting me know about Analog Devices "Technical Tutorial on Digital Signal Synthesis" which can be found at: http://www.analog.com/UploadedFiles/Tutorials/450968421DDS_Tutorial_rev12-2-99.pdf It has pretty much exactly the info I wanted. I say once again: This list is great! Sean -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist