I'm curious what kind of TIC they use? Classics like SRS SR620 or newer
like the keysight 53230A? I have two SR620 and a 53220A I use regularly.
Must be nice to have access to Masers. I have an HP5071A cesium and an HP
5061B cesium at home.
Bill
On Wednesday, October 6, 2021 at 9:19:22 AM
Bill,
I went a ways down that rabbit hole in 2006, ending up with a rubidium
Nixie clock. Then it subsided.
These days I can get all the time nut energy needed at my day job. We run
portions of the Event Horizon Telescope, which requires picosecond
correlation accuracy over several continents.
nixiebunny watch out! Once bit by the timenut bug you might be surprised
where it leads:
For me initially some nice OCXO's, then DOCXO, then Cesium and Rubidium
oscillators and frequency standards... oh and then you better have a better
counter to measure it all... hopefully with 10's of ps
I also use TinyGPS++, though a version I've modified for the MSP430 and
other processors - I've also made it "const correct" and added conditional
compilation so that a reduced size version can be built if you don't need
the maths stuff (that drags in a whole bunch of libraries that may waste a
Many ways to skin a cat!
I use the RTC and it's 1Hz output for normal operation. And then at 3am I
use a GPS (which actually is an ESP-01) to connect NTP and send a fake GPS
message which then syncs the RTC.
The only niggle is DST on the RTC and the GPS sides... I operate with a DST
rule and the
I use NTP. I pull time from the RTC until I get a a sync from the internet
- then I switch to the internet and I update the RTC whenever I get an
update from the network. It all uses UTC, which is converted to local time
for display.
On Wednesday, September 29, 2021 at 2:01:32 PM UTC-4
I'm using network time that my Raspberry Pi re-acquires roughly every 20
minutes, with a DS3232 for backup when the internet is down. I need to
tweak the software a bit more to automatically update the DS3232; right now
I have to use my debug utility to manually update it. But this does allow
My NIXIE clocks have an on-board GPS receiver and I set the DS3232 to
generate a 1 PPS output. On power-up I sanity check the internal registers
and if it looks good I
transfer the date and time to the uP memory. I pre-increment the internal
time and at the PPS IRQ I update the display RAM from
