The Arduino Uno DDS VFO HF signal generator project is designed as a test equipment project for home construction of test equipment used for ham radio. Designed with a frequency setting range of 20KHz to hopefully 75MHz, but spectral performance may be poor. Audio tones from 1Hz to 20KHz have been provided. The software provides “UK” band plan selection and a general coverage mode for odd frequency requirements.  The manual for the signal generator outlines the data port connections, for the DDS VFO unit, the 16 * 2 line display and also the Rotary encoder to dial change the displayed frequency. The manual is a “pdf document”.

The Arduino Uno DDS software for this project is used with the radio ham licence, and may be modified by the operator of the radio ham licence for their individual private needs. The DDS clock frequency in the arduino code will need to be changed to 180MHz for the AD9851, from the current program code setting used for the AD9850 of 125MHz in the test program code.

Arduino Uno controlled AD9851 DDS VFO HF signal generator for VLF 136KHz to 4m band. By Alastair GW0AJU

The signal generator could be used as a signal source for an “Antenna analyser” project. The a black art of Antenna reactance loading for impedance matching, has been for many years of radio communications an awkward subject to follow. The attached webpage entitled “Antenna Lumped Components” to this website, will hopefully help explain some of the principles for an antenna analyser project. The project could use the two remaining analogue ports of the Arduino Uno. This could then follow on to an Arduino Auto ATU project”.