HW-101 Direct Digital Synthesis Project
Why DDS For The Old Rig?
The old HW-101 had worked a lot of DX and had served us well. Its electronics were actually in fair shape but the old VFO gears and bearing had worn to the extent that it did not tune smoothly and would jump a few hundred Hertz on its own. Therefore it had not been used in several years. N4YG hates things that do not work properly and decided to take the DDS approach. The Analog Devices 9835 DDS chip was selected because it satisfied all the requirements for a local oscillator tuning from 5.500 MHz to 5.000 MHz (Yes, it tunes backward).
The project was very successful. A forum presentation was made on the project at the 2005 Huntsville Hamfest. Click on the link above to see the slides from the presentation. If you would like to have an opportunity to construct one of these units for your old HW-101, N4YG would appreciate an email.