You can buy an inexpensive hockey puck GPS receiver for about $30. It comes with a short cord and USB plug. It appears to the computer as a COM port and delivers the GPS data as an RS-232 bitstream at 4800 or 9600 baud, depending on the model. At this price point, you don’t get the 1 pulse-per-second output, but you do get reasonably accurate lat/long coordinates and GPS time accurate to a fraction of a second.
I know of two uses for these receivers. One is to pair the GPS receiver with a software program called NMEATime from VisualGPS. NMEATime runs in the background and keeps the PC’s clock synchronized to GPS time. This is very handy for running FT-8, or for operating in a contest where you want contacts to be recorded in the log at the right time. NMEATime version 2 is shareware, with a free trial download and a $20 fee for continued use. An earlier version of the program is free, and works quite well.
The second killer app for a cheap GPS receiver is a feature that is built into Winlink Express. Winlink has a tool that allows you to send a service message to the Common Message Server (CMS) containing your current GPS coordinates and a brief text message. Your position is shown on a map at the Winlink website a few seconds later, and there are various tracking features available for advanced users. Winlink also automatically forwards the message to aprs.fi, so you can use Winlink to drop “bread crumbs” on the APRS map even if your radio isn’t equipped with APRS.
If you have a GPS receiver, you tell Winlink Express which COM port and baud rate to use, and the software takes the lat/long coordinates directly from the GPS. If you don’t have a GPS receiver connected (or can’t “see” the sky from your operating position), you can enter the lat/long into Winlink Express manually to drop a bread crumb. Look for this feature in the Winlink Express menu under Settings .. GPS / Position Reports.
The GPS receiver I use is GlobalSat BU-353-S4. It is widely available, and there are many similar units available on Amazon, eBay, and many other fine retailers. I make no claim that this model is the best or least expensive option out there. I only know that it works with both NMEATime and Winlink Express (but not at the same time!). It works in my basement as long as I have the receiver near a window or wood wall.
I recently purchased a second BU-353 for use with my go-kit laptop. To my surprise, it didn’t work when I initially plugged it in. Click here to learn how I solved the problem.