Get that sweet, sweet microsecond accuracy via GPS PPS for your NTP server (you are running your own NTP server for your homelab right?) : r/homelab
Frontiers | Time Synchronization for Wireless Sensors Using Low-Cost GPS Module and Arduino
USB GPS Receiver GPS/GLONASS Navigation and Tracking Wiki - DFRobot
USB GPS Module Antenna GLONASSUBX-M8030 Beidou for Arduino Pixhawk Stratux IPEX | eBay
Amazon.com: Stemedu USB GPS Module GLONASS Beidou UBX-M8030-KT GPS Dongle Built-in Ceramic Antenna for Ar-duino Pixhawk Stratux, Better Than VK-162 VK-172 : Electronics
Raspberry Pi 3 Gps Module With L80-39 Gps Chip Usb Port Also For Raspberry Pi 2 Model B B+ Raspberry Pi Zero Free Shipping - Demo Board - AliExpress
Adafruit Ultimate GPS GNSS with USB - 99 channel w/10 Hz updates : ID 4279 : $29.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Adding PPS to a cheap USB GPS stick | Brendan's Radio Blog
PPS over USB
Raspberry PI GPS Module - RobotShop
Mobile Phone Charger Pps | Usb Pd 3.0 Pps Charger | Pd Charger Pps Output - 3port Mini - Aliexpress
GPS-DO expansion board GPS input PPS and 10MHz output port USB PC | eBay
Raspberry Pi GPS Module USB Port – Kuongshun Electronic Shop
GPS-DO expansion board GPS input PPS and 10MHz output port USB PC | eBay
GPS-DO expansion board GPS input PPS and 10MHz output port USB PC | eBay
GPS Time Sync Software for Windows OS – Off Grid Ham Radio OH8STN
GPS Module for Raspberry Pi | 101761 | Raspberry Pi Compatible Hat by www.smart-prototyping.
Amazon.com: Onyehn VK-162 G-Mouse USB GPS Dongle Navigation Module/GPS USB Engine Board External GPS Antenna Remote Mount USB GPS Receiver for Raspberry Pi Support Google Earth Window Linux : Electronics
UART GPS Module With Real-Time Clock
GPS-721U-MRTU | ICP DAS USA Inc - Data Acquisition
TSMX-PPS2 | GPS Receiver Module with PPS Output and Dead Reckoning | Rohde & Schwarz USA, Inc. | AV-iQ