Shortly after joining time-nuts on Corby's recommendation I announced that I wanted to build a complete Dual Mixer for less than $ 200. Richard McCorkle offered to help me with the code for the counters. After completion we started talking about GPSDO's which I had previously worked with Brooks Shera on. We did an extensive methodical review of the system and discovered serious problems with the the AD1861 when used in a filter application. We tested many D/As and switched to the LTC1655. Explored dithering. During that work a German friend that I work with on a different subject made me aware of the FE5680. At the price I bought a couple and was surprised at its performance. Though they had been in Europe for a couple of years I had not seen any thing on time-nuts. I published my observations. At the same time we started work on a digital controller Richard the code and the rest of us testing and analysis. A year in to the program I discovered the FE 405 on ebay and bought 4 for the team. Early on I noticed outstanding performance that was later confirmed by Tom. Focus was shifted to the 405. After many iterations we now have a Universal GPSDO based on which PIC we insert. Works on the FE405, Skip's 5650 and the 5680 that every body bought out of China. Some time nuts have run units for over a year and I feel comfortable to have Cash build, test and sell the units soon. Units he build are presently being tested. We are also assembling a documentation package that will be on his web site. Depending what the interest is there also will be an auxiliary board for the 405 with a divider and output filter for 5 MHz, DC/DC converter, regulators and a PIC for display purposes. This board will not be assembled but comes with two MC output transformers since small purchase will not be economical. All other parts will be readily available. An analog temperature control board, board only will also be available. All boards a 5 X 5 cm and stack able. There was talk about a digital fan control hope some one will step up to the plate. Hope this answers your question. Bert Kehren In a message dated 12/12/2015 11:00:46 A.M. Eastern Standard Time, [email protected] writes:
Bert, For those of us who are not familiar with your work, but who have purchased one of Skip's FE 405s, could you summarize what work you and your group have done on the "FE 405/5680/5650"? You say "Cash Olsen will be responsible for the sale of assembled and tested units." What assembled and tested units are you referring to? Many thanks. Jim Robbins N1JR Can be directly emailed at call @arrl.net _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
