Simple and Accurate Variable Frequency RF Signal Generator

This generator produces any frequency between 500 kHz and 40 MHz with an accu- racy approaching one part in 109, for example 0.01 Hz at 10 MHz. It uses an Arduino Nano, a GPS receiver with antenna, a digital encoder, a small TFT LCD color display, and the Silicon Labs Si5351A direct digital syn- thesizer (DDS). Together these parts cost me about $150. I will also share some interesting applications for this device.