Brian Flynn GM8BJF
Yes the references are not terribly accurate. Even if they are reasoonably stable there is no way of setting them on exactly on frequency
If you want accuracy you will need to arranage an external ref. Looks like that is what the on board SMA is for. Like Neil DBN I have not had any issues dealing with Banggood and have
been happy with purchases from them. I have used the little 0.96 and 1.3 inch OLED displays on sig gens I have built up out of these and other chips. They are nice and clear and sharp if on the small side!