This is for rpi001.Graphs.

Hardware:

Type.	Description.	Sponsor	Webshop
CPU	Pi 4 4 GB Rev 1.1 c03111 (Sony, UK)	None	None
PSU	Cheap USB PSU	None	None
GPS	NEO-6M-0-001	None	None
PCB	Dual Side Prototype PCB V3.00	None	None
Antenna	Cheap active outdoor antenna	None	None

Here is the current time sync status +/- 1 msec. total on the graph.

Due to it is GPS sync
Here is the time sync status 5.0k = 0.005 ms on the graph.

I have made a start image of the linux installation i plan to use. - Guide and image is found under Guides > GPS Sync NTP Server.

The box is on a fibre connection from waoo. Located at my home.
Upstream 300 Mb/s
Downstream 300 Mb/s

2019-09-01 Boot of my new setup, and switch the trafic to this setup.