Thanks to all for the info. I will build my own relay interface to use the open gpio and set this in between the rpm and hat with a pass through header.

I am planning to use my Sense HAT along with four relays (on another HAT). The project is to make a portable satellite tracker. I have most of the hardware on hand, RPi, Sense HAT, Pan/Tilt head, and misc support items. Preparing to purchase a relay HAT to drive the Pan/Tilt unit when I realized I'm...

I'm considering trying one out for use with Software Defined Radio... The SDR requires a headset connection AND a line-in/line-out for the radio's front end. The specs look like this may fit the bill for me.