TAPR QRPi: QRP Raspberry Pi WSRP transmitter – 100 mW output on 20m

I finally got my TAPR QRPi shield on a Raspberry Pi 2, setup with WsprryPi software to transmit WSPR (Weak Signal Propagation Reporting) signals, and the results from just 100 mW output on the 20m Amateur Radio band are nothing but amazing. Here’s a screenshot from the WSRPnet.org site this evening over the past couple of hours showing stations that have received my 100 mW signal to a roughly cut dipole wire antenna (zipcord electrical wire split into two) for 20 meters plugged directly into the TAPR QRPi board:

When I got my first spot from VA7MM in Vancouver I was pretty happy with that. 744 miles on 100 mW is pretty good going. But then in the following couple of hours spots from stations even further afield started popping up on the map, including K9AN in Illinois, that’s 1784 miles from here in Davis, California, on just 100 mW. That’s absolutely incredible! (thanks to everyone that spotted my signal!)

This is my second attempt to get this working. My first attempt on a Raspberry Pi 1 Model B didn’t get any spots over a several hours period one weekend, so I wondered if something was not working right on the original Pi model (remembering I’d read somewhere what the WsprryPi software was updated to run on the 2 and 3 recently). This afternoon I installed WsprryPi and the QRPi board on a RPI 2, and the reports started rolling in!

My antenna is just a wire dipole, strung between two bushes in the back yard at roughly 5ft above ground, with the broadside aiming roughly north/south.

Update: it’s 7:30pm local and my signal is being received almost all the way over on the East coast!

Booting Raspbian Jessie to a shell prompt

Raspbian Wheezy on the Raspberry Pi used to boot to a shell by default, but on Jessie, the default is to boot in graphical mode to the desktop. You can easily change this with raspi-config, either from the desktop menu using the gui app or raspi-config from the command line. Step by step instructions in this post.