uBITX M1, M2, M3, M4

Michael LeBlanc
 

I don't have a uBITX, but I'm considering building one from scratch. Looking at Farhan's 2017 schematic, he has indicated what looks like a 4-pin header labeled M1, M2, M3, and M4 which are grounded. There is a matching M1 in the audio section, and M2 is also in the audio section. Am I correct in interpreting these as jumpers that can be added or removed? If so, what is the purpose of each jumper?

Final question: are there any builders out there who, in addition to Farhan, of course!) have built the uBITX from scratch and have some words of wisdom to share?

Michael VE1LEB

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