If your frequencies of interest can be divided down to to the 1PPS range, the TAPR TICC makes for an excellent frequency counter. The TADD-2 Mini divider handles 1/2.5/5/10 Mhz or with a PIC chip swap 1/5/10/15 MHz. The TICC has around 100 ps of jitter so you can get 1E-10 resolution at 1 second... the TICC noise floor at 1000 seconds is less than 1E-13. I used the TICC to adjust my 5065A and FTS-4060 cesium C-fields. Referenced to a 5071A, the results are better than 0.00002 Hz (the spec'd limit of the devices). Attached is a plot of the FTS-4060 using a 5071A as the reference. Over a 1000 second interval the average frequency is off 0.000002 Hz. Ignore the yellow debug output in the plot... I'm currently working on how to scale and plot the new MTIE (Maximum Time Interval Error) data that Heather can now calculate.

Hi > On Apr 26, 2017, at 2:31 AM, Mark Sims <holrum@hotmail.com> wrote: > > If your frequencies of interest can be divided down to to the 1PPS range, the TAPR TICC makes for an excellent frequency counter. The TADD-2 Mini divider handles 1/2.5/5/10 Mhz or with a PIC chip swap 1/5/10/15 MHz. The TICC has around 100 ps of jitter so you can get 1E-10 resolution at 1 second... the TICC noise floor at 1000 seconds is less than 1E-13. > > I used the TICC to adjust my 5065A and FTS-4060 cesium C-fields. Referenced to a 5071A, the results are better than 0.00002 Hz (the spec'd limit of the devices). > > Attached is a plot of the FTS-4060 using a 5071A as the reference. Over a 1000 second interval the average frequency is off 0.000002 Hz. This gets one off into the area of “how do I build a 9/10/11/12 digit a second counter?”. As everybody has guessed by now, that’s the project I would do rather than a straight counter. TICC, F7, a dirt cheap FPGA card …. Bob > > Ignore the yellow debug output in the plot... I'm currently working on how to scale and plot the new MTIE (Maximum Time Interval Error) data that Heather can now calculate.<ticc.gif>_______________________________________________ > 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.