Case for the QRP-Kits 41 dB Step Attenuator

thingiverse

Pacific Antenna/QRP-Kits (qrpkits.com) offers a compact 41 dB step attenuator kit capable of handling small amounts of transmitter power, as detailed on their website. However, I discovered no available cover for the kit. My tendency to drop metallic objects onto open electronics occasionally prompted me to take control and learn basic 3D CAD drawing skills to design one myself. Using Fusion 360, with assistance from a friend, we started with simple projects, but this step attenuator case is my first solo design from start to finish. To print the case top and cover without supports, ensure the flat surface faces downwards. This will result in stronger prints and minimize support removal difficulties. I recommend printing at medium to high resolution for optimal strength. Be sure to carefully tap the 4-40 by 1/2 inch self-tapping screws into place using 1/2 inch long machine screws. Additionally, consider enlarging the corner holes on the PC board to accommodate the 4-40 screws if necessary. If done properly, this will not affect performance. It's also crucial to trim all protruding pins from the bottom of the board to ensure a snug fit between the case top and bottom. The tolerances are quite tight to prevent board movement once assembled. The Fusion 360 files for the design have been included, allowing anyone to customize it according to their needs.