The assembly instructions on the HFSignals site are for a disassembled sBitx. But what they are shipping now is the basic kit -- a mostly assembled radio that lacks the display and the Raspberry Pi. The instructions on the site don't apply perfectly; there are things you don't need to do at all, and things you will do differently because parts are already installed. Here is what I found when I put mine together.
0. Opening the case
You're getting a mostly assembled sBitx so you have to detach some things to get at the inside. Unfasten the front panel by removing four M3 screws; two at the top of the front of the radio and two at the bottom of the front. Pull off the front panel. Unfasten the top panel (the one with the speaker) by removing four M3 screws from the top of the radio. Pull off the top panel. Unplug the speaker cable from the digital board.
1. Preparing the digital card
Do the first three steps as written. Those attach the DSI cable to the Pi and install the SD card. The DSI cable comes with the display, not the sBitx. The two ends of the cable are identical; it doesn't matter which way you put it in. (My cable didn't match the one in the pictures; the cable was built the other way around, with the writing on the blue side instead of the silver side. Follow the instructions about the blue and silver sides and ignore the writing.) This cable installs VERTICALLY, sticking up from the Pi. The standoffs are already attached?to the digital board inside the radio, so skip step 4.
2. Installing the main board into enclosure
Everything in this section has already been done. You can skip it.
3. Preparing the front panel
Skip step 1 (install the display back plate); it's already there. Do steps 2 and 3; note that the display goes into the radio with the five pin connector at the top and the ribbon cable at the bottom, as shown in the picture. Skip the rest of this section; it's already done.
4. Installing the front panel
Skip this section for now. You will put on the front panel later.
5. Installing the digital board
The digital card is already plugged into the radio main board and attached to its mounting bracket. So instead of doing what this section says, you're going to plug the Raspberry Pi into the digital card where it is already mounted, rather than taking it out. The order of assembly is changed.
First, plug the Raspberry Pi (which already has the DSI cable attached; you did that earlier) into the digital card. Be careful to get it aligned correctly, with all the pins and sockets meeting each other. When you have it in place, secure the Pi with four M2.5 screws. If the screws don't line up easily you probably don't have the Pi aligned correctly; check again!
Next is the trickiest part of the assembly; attaching the DSI cable to the display. Hold the front panel near the rest of the radio but don't attach it. Release the plastic clamp on the DSI socket. Plug the loose end of the DSI cable into the display board with the silver side facing up. (This cable goes in HORIZONTALLY, flat to the board, unlike how it plugs into the Pi.) IMPORTANT: there will be a half twist in the DSI cable if you have both ends plugged in correctly; this is normal.
Plug the 10 pin encoder cable into the digital card. It will only go in one way. Attach the front panel to the radio, using the four M3 screws you removed earlier.
There is one more cable to connect, the brown and black power cable. The power cable has no connectors at the?other end, only at the end that connect to the digital card. The assembly instructions show the power cable wires simply twisted around the pins on the display, an arrangement I didn't care for at all. Instead, I used two wires that came with the display that have Dupont connectors on each end, the red and black ones, cut them in half, and spliced the ends of one half of those wires to the brown and black cable: black to black, brown to red. Solder each pair of wires together and seal the splices with heat shrink tubing. Connect the two pin connector to the digital card. Connect the loose ends to the display; the red wire goes on the end near the DSI connector (labeled 5V) and the black one goes at the other end (labeled GND). You do not need to connect anything to the other three pins.
6. Closing the enclosure
The side plate is already attached, so you can skip the first step. Plug the speaker back into the digital card. Put the top panel back on the radio and secure it with the four M3 screws you removed earlier.
You're done. Enjoy your new sBitx!
