Henk, it will be available to every one the challenge will be buying in groups, I definitely do not want to be in the mail order business. Bert In a message dated 10/2/2009 10:11:49 A.M. Eastern Daylight Time, h...@deriesp.demon.nl writes:
Hi Bert, This is amazing and I hope that you can make it available for us to build one. I am very interested. regards, Henk > A couple of months ago I did announce that I plan to build a dual Mixer > based on the NBS design with minor updates and add a counter section. All > with > a cost goal of $ 200. Having all parts in house the goal has been reached > when boards get ordered in quantity ten. Thanks to inputs from Bruce > Griffiths, Corby Dawson and Richard McCorkle I do have prototypes and am > in the > testing phase. Richard has written the code for the processors and the > counter board is assembled along with the simulator to be send this > weekend to > Richard to allow him to test his code. The Dual Mixer will be assembled > and > tested this weekend and will go next week to Corby to see how good it > performs with his Maser and compare to his NBS unit. > What makes this unit different is that it has five counters running at > 100 > MHz giving at 1 Hz a resolution of 1 part E 15. The counters talk through > a > RS 232 interface to a computer. This will not only give Allan Variances > but also show the frequency difference with the same resolution at a 1 Hz > rate or if the offset Osc. is 10 Hz ten times a second. There are also > outputs > for those that want to use their present counters for Allan Variance. > Right now the PC interface is RS 232 but long term I would like to see > USB, > because the counter uses so little power it could be powered by the PC. > Isolation to the Dual Mixer is through high speed Opto couplers. > Long term I would like to encourage some one to design a two line > display > that shows Allan Variance and frequency difference and also records the > information on a USB stick. That would allow total isolation from power > since > it could run on one 12 Volt battery. > What is next. > Once Richard has checked his programs and Corby has checked the Dual Mixer > I will incorporate any changes in the boards order and test one more set > and then make all information available to all. Richard has also > graciously > agreed to make his code available. In the meantime I have two extra boards > and part kits for some that are also willing to make a contribution to > the > project and I am not talking about money but further the project. Once > finished I will also have a few more kits available since with the > exception of > the boards I purchase enough for ten units. The next board order (after > check out) will make it ten. I also have six HP 10811 that have been > checked > to 20 Hz offset making them usable at 10 Hz offset at 5 MHz! > If every thing works as planned, my goal is to have every thing released > by > 1 November. Cross your fingers. > The Dual Mixer is 4.2" by 2.8" fitting into a standard German 72x111x20 > metal box for shielding. the counter is 4.8"x2.2". > Bert Kehren > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.