WSPR it's a protocol, developed by K1JT Joe, designed for probing potential propagation paths with low power transmissions. Normal transmissions carry a station callsign, maidenhead grid locator, and transmitter power in dBm.

This App, used in combination with an hamradio transmitter, allow you to send a signal that, if received by someone, will be reported on wsprnet.org.

This is also great tool for checking your antenna system or comparing two radio,

Inside the App you will also find the connection schema, under "Help" menu, for radio with VOX and PTT!

Have fun! 73!