This board interfac on one side transmitter and receiver and, on the second hand the Arduino Due. A computer (such as a Raspberry Pi for example) is connect via USB to the Arduino. This provide a complete controler for numerical repeater.
I design this PCB, like some other OM, with components in conventional sizes (DIL integrated circuit, resistors quarter-Watt, …). There is still a quite small component that is the TCXO . To eliminate an CMS component, I chose to install a HCMOS TCXO directly compatible of 3.3V expected voltage of the Arduino. The selected reference is the FOX924B-12 with an announced stability of +/- 2.5 ppm.
I replaced the bulky components (in TO220 housings) with equivalent components in TO92 case. The tests are to be carried out. However, even the largest components can be positioned, as I left the possibility of mounting one or the other versions. The board plugs directly on Arduino Due.