The HamHUD II+ project has been re-kindled. The proto-type is being built and tested by Dale Seaburg KG5LT and James Ewen VE6SRV. A few others are lending a hand in on the schematic and code as well. This new version is a enhancement of the current HamHUD II. A new modem board is being developed to be stacked right on the back of the board stack. Below is a link for the modem board schematic in Adobe .pdf format.
To view the schematic, just click on it. To save it, right-click on the link and choose "Save Target As...".
Below is a simple diagram of what the board stack should look like once the modem board is added. The three sections or layers are stacked on each other using insulated spacers. Although there is some talk about using metal spacers to carry the ground from layer to layer.