Mean-squared detector on AD834. Scheme figure 3 an-212.

My layout is assembled on a board made of double-sided textolite. Moreover, the lower layer is a common chain. At the top, the components are located and the rest of the circuits are located. The data sheet for the DIP enclosure says:

"The IC socket is mounted on a ground plane with a clear area in the rectangle formed by the pins. This is important because significant transformer action can arise if the pins pass through individual holes in the board; it can cause an oscillation at 1.3 GHz in improperly constructed test jigs. "

I use a chip in a SOIC enclosure. Maybe you should remove the foil in the lower layer under the chip?

The diagram shows that the input signal is applied to the input X in negative polarity, as opposed to the input Y. why in this case, the output is positive, because 1 * -1 = -1?