Saturday, October 16, 2021

Time-sync'ing a PC with a GPS dongle

In preparation for portable operation with my incoming QDX transceiver, I ordered a $12 GPS dongle from Amazon yesterday.

Reviews are almost universally 5-star and, at only $12 and a good refund policy, why not give it a try.

BktTimeSync is a small (and free) 3.7MB program that synchronizes a PC's clock with time signals received by the GPS dongle.

The GPS dongle arrived today. Nothing in the way of documentation was included but I was still able to have it working and maintaining my PC's time within 10 minutes of opening the package, thanks to this video from Troy KF7SEY. 

If you're interested in this device for accurate time while portable, here is the sequence of setting up:

  • Download and install BktTimeSync but don't run it yet
  • Plug in the GPS dongle. Wait while Windows installs the driver and assigns a COM port
  • Initially, a red LED will be illuminated on the dongle. After about two minutes (initially, then 20 seconds) the red LED will blink green once per second, indicating reception of satellites
  • Open BkTimeSync and configure it as shown below, replacing "COM5" with whatever port was assigned


I had no problem getting a lock on GPS satellites indoors. Simple, cheap and it works great.




  1. Nice gadget John. Would it be possible to derive an ultra stable 10 MHz (e.g.) from this device ?73 Ron PA2RF

    1. Hi Ron - that's a good question! These seem to do it with GPS:

      but I don't know what's involved in going from NMEA to a 10MHz sine wave.


  2. John,
    ICOM recently came up with their own solution for the time sync from PC to the radio:
    or from Android OS device to the radio:
    or search for ST-4003A in Google Play

    Also, GPStool for Android OS:
    It allows automatically input GPS location data from Android device to the radio

  3. Hey John— there is a free program called JTSync written by a German ham that will let you sync the time on your computer with no internet or extra equipment needed. It works by listening to FT8 signals. It works perfectly. Great when your are in remote areas. Please spread the word. 73, Chrissy KA5PXK