Table of Contents

AGC and Smeter mods

If you look at the ubit.net website or on the Groups.io of uBitx, you will find a dozen of AGC mod, and at least the same number of Smeter builds.

I've made a choice for this solution and the idea is to build one PCB for those 2 different functions, to add to the uBitx.

AGC by VK2ETA

When you start to look in details with the uBitx, it appears that the lack of AGC is very annoying for the ears. So, even I still haven't received my uBitx, I think it's a good idea to prepare this mod right a way.

So, this project is based on the VK2ETA AGC mod, with this schematic :

It is quite simple, based on a MAX9814 (the same board I use for the mic amplifier). No fancy components, so I think it will not too difficult to build.

Smeter by KD8CEC

As I plan to use the CEC firmware instead of the stock one, I think it's a good bet to test the Smeter by KD8CEC, which is the developper of this firmware. I think it'll make easy to setup on this page.

The schematic is very simple too :

PCB design

Now the idea is to put those 2 circuits on the same PCB and make it. I'm not a pro with PCB design as this one is my really first one.

I've made some projects with strips board, but the idea here is to design a PCB to engrave with my CNC using the english method of making PCBs.

I use Kicad for the design, which is free and after 2 or 3 hours looking at tutorials on Youtube, is not too difficult to use.

Here is the design of the 2 circuits :

And the PCB to engrave :

Engraving

The next step is to engrave the copper board.

For this, we need a GCODE to feed the CNC router. I've used FlatCam, which is really easy to use.

In fact, you can export the PCB design in Gerber file format in Kicad and then import it in Flatcam, configure your tool and you'll have a good GCODE to process.

Flatcam view :

Mounting components

Testing

Files

All the files are available in the DropBox folder of the whole project