I have a 3105 in a box, but no manual, and another type of box and a little different display, but says 3105 on outside, too.
The ability to do pictures back then seems limited, but there is a description on page three. A nice photo with positions listed would be less confusing.
Remember that the output of the anemometer is an AC voltage, so you can measure that if you can't figure this out otherwise. And the battery sends a voltage (which you calibrate with the potentiometer as explained) to get full scale reading. As the battery ages you recalibrate.
I know one that my brother had on his farm back in mid 1960s had a multicolored ribbon cable and the one I have is a gray cable with no easy to identify markings.
[ You are not allowed to view attachments ]
[ You are not allowed to view attachments ]