Hello everyone, this is the first time I actually make a modest n00b contribution to time-nuts, so please be kind with me 😊 I will appreciate any comments, criticism and suggestions. Aside from GPSDO and Rubidium Oscillators, I am also quite interested in radio clock receivers. So I found the EVERSET ES100 WWVB receiver on Amazon, ordered it, and wrote some code for it. I’ve only had this for a couple days, barely enough time to hack together a few lines of python code which I use as a test program. Once I work out all the kinks and add all the functionality I think is needed, I’ll then go ahead and write an SHM based refclock for NTP, in C code of course. GITHUB link: https://github.com/fiorenzo1963/es100-wwvb-refclock I hope it’s okay to post partial work (in the spirt of open source “release early, release often”. The receiver is fairly inexpensive, and I’m using a Raspberry PI 3 which I had lying around. I’ve only had this running for a few hours, so I can only show every preliminary data. Phase error is measured against the local oscillator, disciplined via NTP against 3 local GPSDO servers. I’ve oriented the dual antennas at 45 degrees of each other, with their intersection roughly pointing to Fort Collins. First results: - These logs have been taken from 2019-11-15T11:09:18Z to 2019-11-15T22:35:49Z - RX statistics indicate a successful RX rate of 44% RX_OK_ANT1 1 /* RX count on ANT_1 */ RX_OK_ANT2 113 /* RX count on ANT_2 */ IRQ_NO_DATA 145 /* RX unsuccessful, WWVB retrying (currently simply timed-out) */ - Phase (aka offset) error statistics compared against a local GPS-disciplined stratum-1 clock - Average ~ -10 milliseconds - Most samples are within +40/-60 milliseconds - All samples are within +60/-120 milliseconds - Phase (aka offset) error plot, with moving average (note that RX errors are ignored here) [image: alt text] <https://raw.githubusercontent.com/fiorenzo1963/es100-wwvb-refclock/master/images/wwvb_offset_error_20191115.jpg> Hope you enjoy, Cheers, -- Fio Cattaneo Universal AC, can Entropy be reversed? -- "THERE IS AS YET INSUFFICIENT DATA FOR A MEANINGFUL ANSWER."