zBitx case mods

I felt the need for a fan, unfortunately (I don't like fan noise! better use efficient electronics and a proper heatsink!) and happened to have a 40mm one lying around. This is not optimal, but it's something; and it can be modified for something else later. A 12V fan of course runs a little slower and quieter on 8.5V. So here we have replacements for both side panels, with holes; and on the right side, I superglued the fan shroud to the hole above the BNC connector.

Later, I switched to a 30mm fan, and managed to install it with header pins so that it runs whenever the radio has power, and is removable if I need to make further changes. I happened to have some M2 (?) brass standoffs that fit perfectly in the fan's mounting holes.

The scad file imports `zBitx_HFSignals_final - edited.stl` from https://github.com/afarhan/zbitx