ws there is no NIH here, please share how you do it for $ 10, I always like to learn, and I have not been a member that long. Is there a link to a specific design? Thanks Bert In a message dated 5/11/2010 1:47:15 P.M. Eastern Daylight Time, warrensjmail-...@yahoo.com writes:
For the Really cheap time nuts, It sounds like Bert Kehren has done a great Job building a Dual Mixer tester. There are other simpler, less standard ways to get good data for Allan Variance and small frequency differences. My VERY simple $10.00 analog tight PLL Tester BB (Previoulsy posted) pretty much accomplishes the same goals as his, and it can do 1e-13 in a second, and 1e-11 in 10ms (limited of course by the single reference Oscillator used) A simple test that most can do at home, and still challenges the best high end testers out there is Tom's the swinging Oscillator test. http://www.leapsecond.com/pages/10811-g/ (The results from my PLL tester is attached) ws ****************** ----- Original Message ----- From: <ewkeh...@aol.com> To: <time-nuts@febo.com> Sent: Tuesday, May 11, 2010 7:02 AM Subject: [time-nuts] Dual Mixer > The Dual Mixer project is nearing completion. > Let me refresh every ones memory as to my goals. > a) Total cost less than $ 200 > b) 1 E-13 with a one second offset > c) use parts attainable by every one > d) easy to assemble only a few surface mount parts > e) a five channel counter that yields 1 E 15 resolution and interfaces > directly to a PC via RS232 or USB > f) A counter that also gives you instant frequency difference at the > sample rate, not only Allan Variance > g) Modular so one can use only the Dual Mixer > h) Modular so one can use multiple units to do simultaneous comparison > of > more than two oscillators. > i) Isolation between D/M and counter so that the counter can be powered > by the PC USB port > > I am happy to report that all goals have been accomplished, attached is a > picture of the D/M, limitation of the file size does not allow me to > attach > an actual board picture, but if you contact me direct I will send you > one, > the final board is actually nicer since the first layout had to > accommodate > several variances. > > The D/M part leans heavy on the original NIST unit with a few > substitutions > and recommendations from Bob Camp. Also beside Opto Couplers SN65LVDS1's > have been included for those that want to use other counting methods. > Selection of filter capacitors allow the use at other offset frequencies > such as > 10 and 100 Hz. The D/M fits in a standard 74 X 111 X 20 mm Euro case and > the counter can be stacked below or next to it using the Opto Isolators > as > the inter connect. The SYPD-1's fit right on the board but connections > are > included to use the HP 10514 A. As a matter of fact removing the HP mixer > board from its housing fits it nicely on the board and every thing is > still > inside the housing. > The counter will handle 1 an 10 Hz offset with a 1 E 14 resolution at 10 > Hz. Thanks to Richard Mc Corkle we have great drawings and code, available > to > every one. > Code, drawings, list of material and PC board layouts and its file, will > be available to every one once the project is completed. > I need help in the following areas > a) help me create a nice set of drawings that are computer generated > something I am not able to do > b) create the computer program that takes the output of the counter board > and allows Allan Variance plots, frequency difference and dual temperature > readings and plots using RS232 and USB. > c) an independent test by a third party. > As I said previously, I am not getting in the business of supplying parts > but will work with people that will help achieve the three points listed > above. Presently I have boards on order and will have two uncommitted > board > sets and probably also component kits. > Please contact me directly. > Again thank you Corby Dawson, Richard Mc Corkle and Bob Camp. > Bert Kehren Miami > > _______________________________________________ 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.
