additionally needed material:
Insert the side parts of the tinplate housing into the covers and assemble them on a trial basis:
Using a hot soldering iron, solder the side panels (only the side panels, not the lid) so that a sturdy frame is formed.
Insert the circuit board on a trial basis. The frame has a small protrusion on the inside, where the tinplate parts lie lie on top of each other. Use a file to file off the PCB at these two places so that it fits well into the tinplate frame. It is not soldered, just put it in on a trial basis. Now you can take the measurements for the connector cutouts. Cut (e.g. with a Dremel) or file three slots with 10 mm height and 6 mm width.
Using the hole plan, drill six 2.5 mm diameter holes (about 8 mm deep, or clearance hole) in the aluminum plate or heat sink, then cut M3 threads. A drop of oil can greatly extend the life of the tap. Figure 5 shows the dimensions of the board. Attention: these are the dimensions of the PCB. If you measure the tinplate housing, you have to add its wall thickness and gap dimensions if necessary! It is best to place the board loosely in the tinplate frame for measuring.
As described above for the tinplate case, file off the corners of the PCB so that it fits into the tinplate frame.
In these pictures an aluminum plate 57 × 78 mm and 20 mm thick was used. The UpConverter is placed on the pre-drilled holes and fixed with the spacer sleeves and M3 screws. The thermal pad is 3.15 mm thick, and the spacer sleeves are 3 mm thick. This compresses the pad by 0.15 mm and provides a good heat conductive connection. If you use the 2mm pad or a stack of 2 pads, you have to use different lengths of the spacer sleeves. It is also important that the screws are tightened evenly and that the board does not bend in the process. Otherwise damage to the SMD components may occur. These are much more sensitive in this respect compared to wired components.
Important. Do not use 3 mm washers, they might touch the tracks! Plastic washers or 3 mm sections of brass tubes are best suited. Now the tinplate frame is put on until it rests on the heat sink. Then it is soldered to the edge of the board. For the 12 V supply, you can install a banana jack, or a multi-pin connector (e.g. Sub-D 9-pin) if you also want to feed out PTT and the serial output. But this is not absolutely necessary, because in most cases you can connect the PTT with a jumper firmly to ground:
After connecting the 12 V supply line and possibly plugging jumpers for frequency selection, the lid of the tinplate housing can be put on. Finally, a label is glued on. The lid is not soldered, because you may have to make settings on the board (e.g. jumpers).