The Micro-40S is a single board SSB Transceiver by Indra Ekoputro YD1JJJ.  I didn’t buy one of these thankfully, but a friend brought one for some TLC.  These things are supplied rather badly, ready built and working.  The one that came to me had a short circuit IRF510 output PA MOSFET.  An easy fix but what current to set the PA standing bias to?  There was no information in the sparse documentation and YD1JJJ did not reply to any e-mails.  In the end I started at 50mA then increased the bias whilst transmitting in to a dummy load, until the signal was clean at just below the specified output.

Blekok Micro-40S

The Micro-40S was realigned as part of the process, as the bandpass filters were a mile out.  But the Blekok receiver seemed deaf and sounded dreadful.  The bandwidth of the ladder filter is way too narrow for SSB and the receiver IS INDEED DEAF.  I found comments from other owners which confirmed this and even some similarly dreadful sounding YouTube videos.

I’m sure you could work out how to fix the design flaws in this design, but why would you when there are much better ones out there?

If I was you, I’d avoid this project and go with something way better such as an ILER-40 (or one of the other ILER range) or one of the BitX projects from VU3SUA