[time-nuts] uBlox F9T testing - best settings?

[Anders Wallin]

Hi all, we are testing an uBlox F9T (RCB-F9T timing-board) for the past few
days. Small uBlox puck antenna in a not-so-great location.
I get an ADEV of 3e-8/tau long-term (see pictures or blog)

Through the UART there are lots and lots of settings to tweak with the
uBlox software - I am wondering if anyone figured out optimal settings for
stationary operation and best stability when the pulse1/pulse2 outputs are
configured for 1PPS and 10 MHz. Is it using just GPS (or multi-GNSS?), dual
or single-frequency, as the default setting?

Also, it seems that on 10MHz there is dithering (8ns granularity?) - is
there any simple way to generate a round-number out of the uBlox, and use a
(simple) multiply/divide to get dithering-free 10MHz?

we made a carrier-board for the RCB-F9T with an USB/UART conversion and
buffered dual BNC outputs for pulse1/pulse2 - this might be published
later...

Further down the road, if the F9T really can do dual-frequency
observations, and either the receiver clock 1PPS measured (TICC?) against
an external 1PPS, or the entire receiver clocked from external 10M/1PPS -
and dual-frequency RINEX generated from this - then there seems to be an
obvious opportunity for making a low-cost dual-frequency time-transfer
setup? Or am I missing something?
PPP with F9T seems to be possible:
https://gpsd.gitlab.io/gpsd/ppp-howto.html

thanks,
Anders
board https://www.u-blox.com/en/product/rcb-f9t-timing-board
antenna https://www.u-blox.com/en/product/ann-mb-series
blog http://www.anderswallin.net/2019/09/ublox-f9t-test/

[image: uBlox_oadev_tdev.png]
[image: uBlox_F9T_timeseries.png]
-------------- next part --------------
A non-text attachment was scrubbed...
Name: uBlox_F9T_timeseries.png
Type: image/png
Size: 90786 bytes
Desc: not available
URL: <http://febo.com/pipermail/time-nuts_lists.febo.com/attachments/20190921/50b40261/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: uBlox_oadev_tdev.png
Type: image/png
Size: 76151 bytes
Desc: not available
URL: <http://febo.com/pipermail/time-nuts_lists.febo.com/attachments/20190921/50b40261/attachment-0001.png>