Recently I bought a PCB, ordered the components, and built myself a NinoTNC N9600A3. Just curious how it would work and perform compared to several old TNCs and the more modern soundcard modem software.
The building instructions are very clear and comprehensive. Anyone with a little bit of soldering skills can easily build one. After building and some basic testing I noticed the firmware was a bit outdated already. Nino is releasing updated versions fast it seems. Therefore I’ve updated the version to the latest version available at the time of building (2.51).
Now it was time to do some testing and comparison for operating on CB (1200bps AFSK only!). It seems to perform very average overall but is slightly performing less with weaker / more noisy signals compared to some old-skool TNCs with a TCM3105 or AM7910. As expected it’s nowhere near the RX decoding results you get with a piece of soundcard modem software like Direwolf (1.5) or UZ7HO’s Soundmodem (1.0.5).
The NinoTNC also seems to suffer a bit due to RF getting into the dsPIC microcontroller. Placing the (optional) inductors didn’t have a satisfying effect and on a regular basis the dsPIC totally ‘stalled’ or the program counter was getting corrupt somehow.
I noticed the PCB design doesn’t have any groundplanes I thought incorrectly the PCB design didn’t have any groundplanes but that doesn’t seem to be the case. Using a metal case, properly connected to the NinoTNC’s ground was my best option to get rid of this problem. I’ve just placed it for testing in a small metal case and didn’t see the dsPIC ‘stall’ a single time again.
It was a nice little project to build and test but I don’t think I’m going to use the NinoTNC a lot. More like another ‘nice to have TNC’ for my collection.