At anytime, there might be half a hundred dozen different things on my work bench slash radio desk that can take up my interest for a fleeting moment. It might be a new toy, a new component, or just something shiny.


I was reminded of this today when i picked up part of the Direct Conversion CW rig i have been building for what seems like forever. I had some boards build to house a micro controller and DDS unit and I started to fiddle about with it and noticed that the output was very low.

The DDS should be putting out about 250mv rms at 7mhz, but i was only seeing 50mv rms on the scope. Something was up and i had never noticed what or why before. Pulling things apart and checking things separately showed everything was working right, but when plugged into the board it all went wrong again.

Turns out, I was measuring things at different frequencies and amplitude out of the DDS depends on frequency. Measuring 40mhz in the board and 7mhz out of the board, but being distracted i did not notice my error til much later. So, i have now cleared off the work bench, the only things on it now are stages of the DC receiver and everything else i have been tinkering with has been shelved. Time to get some focus and get this things build already. So tonight, i will build the DDS buffer amp and add the mixer as well.

More to come on that soon. 🙂


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