There are many ways to test HF antennas ranging from simulation to various antenna analyzers and bridges. However, nothing can replace simply using the antenna to see how it works. Just as — supposedly — the bumblebee can’t fly, but it does so anyway, it is possible to load up some bed springs and make contacts. But it used to be difficult — although fun — to gather a lot of empirical data about antenna performance. Now you can do it all with WSPR and [TechMinds] suggests a moderately-priced dedicated WSPR transmitter to do the job. You can see a video about the results of this technique below.
While WSPR is often cited as taking the fun out of ham radio, it is perfect for this application. Connect the transmitter and a few hours later, visit a web page and find out where you’ve been heard by an objective observer. If you had a few of these, you could even examine several antennas at similar times and conditions.
The transmitter has its own GPS so it doesn’t require much configuration. You do need to set the frequencies you want to use and — presumably — the SWR at these frequencies of your antenna will be acceptable. Of course, you also need to set your callsign and transmission schedule. You can manually set the location code if you don’t want to get a GPS setting.
Once set up, you don’t need the computer connected. After some time, you can just visit the WSPR.org web site and view who has been able to hear the little low-power transmitter.
Of course, you don’t need a dedicated beacon do pull this off. Use your normal radio or put together your own beacon. If you want a refresher on WSPR, [Dan Maloney’s] $50 Ham has you covered.