I have a couple of these AD831 mixer boards that I bought off ebay ages ago. Been thinking about building a receiver out of ebay modules just for laughs. So i got them out of the parts trays and fired one up to see if they are even working and functional. Looking at the output on the spec an, it would seem they work plenty fine and are within spec.
Hi Rob, I’m following in your footsteps with the same Chinese AD831 board. I was doing some preliminary checking of mine, and would really appreciating knowing your supply voltage and any conversion gain you observed.
What I think I’m seeing on my rudi Rigol spec analyzer is 5 to 6 db of conversion gain at 9 volts. This seems to show up until I get down to about 4.25 volts, where the gain drops to unity and then falls off below that.
Did you see anything like this? I always suspect my measuring technique when this happens, but I’ve learned to ask 🙂 It looks like an amazing drop in fix for some old otherwise good NE602 rigs.
Thanks, Scott ka9p
5V is what i powered them with. I did not calculate conversion gain, but i remember right, rf was something like 0.001v and the lo was either -10 or -7 dbm. I have never tried to work out conversion gain, so im not sure on that. They are good parts though and i really need to use them in something more than just this test.