Hi Magnus You are right, I could compensate it in the software. I've tried that. The software sets sig=ref=10MHz and measures start-to-stop time t1. Then, it sets sig=ref=5MHz and measures time t2. With t1 & t2, I could get the time difference between the start path and the stop path. Repeat it 1000 times every second and get the RMS value of it. I use the RMS value to compensate the result of the following second, but get much worse ADEV chart.
I've uploaded the verilog code and schematic to http://www.qsl.net/bi7lnq/freqcntv4/code/freqcnt_v4.zip and http://www.qsl.net/bi7lnq/freqcntv4/freqcnt_bi7lnq_v4.pdf. The idea is from http://n1.taur.dk/permanent/*frequency*measurement.pdf _______________________________________________ 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.