First: DO NOT put anything else on that RCVR/AMP key yet. Good call on that.
Next: With jp1 you could download the entire contents of the remote as it now is and very easily change the device. But you don't have that, so...

Your next impulse was correct, you can control the Technics with the SAT key. It's called a Device Mover function, and is documented in your "manual" (you know, that cheesy little piece of paper they put in there.
Jim