I downloaded Arduino Projects for Amateur Radio by Dr. Jack Purdum, W8TEE, and Dennis Kidder, W6DQ a few months ago. It’s a really good book with some actually useful projects in it. If you’re new to Arduino, I might suggest starting with Simon Monk’s Programming Arduino: Getting Started with Sketches, but if you’ve got the basics down, the Purdum and Kidder book is great. One of the projects detailed in the book is a direct digital synthesizer VFO controlled by an Arduino and tuned with a rotary encoder. I thought this was an interesting project, but was unsure how to actually use it.
Imagine my delight when the March issue of QST came out and featured an article on building a complete QRP CW radio by Purdum, Kidder, and Farrukh Zia, K2ZIA. The project uses the DDS VFO circuit from the book, and along with a forty-9er QRP transceiver kit. The article describes modifications to the transceiver kit to replace the fixed frequency crystal oscillator with the VFO. The authors have even created at PCB and basic parts kit for the VFO that you can order from Mr. Zia via PayPal.
I started collecting the various parts necessary: Arduino Nano, Forty-9er kit, AD9850 DDS, rotary encoders, and the VFO PCB/parts kit. I also had to collect a few odds and ends for the Forty-9er modifications: 22μH inductor, 150pf capacitor, Zener diode, and some header pins. I had everything I needed to put the modified transceiver kit together over the weekend. So far everything has gone to plan. Once the VFO kit arrives, I’ll get to work putting the rest of the rig together. I’m anxious and a little nervous to see if it works.
I set a goal this year to activate at least one National Park for the ARRL National Parks On The Air with QRP CW. I’m hopeful that this project will enable me to meet that goal.