on the Sr3300T spektrum rx...a question

[Arct1k]

Yup I was right....

From the manual

Power the receiver through any port that is not
a 3.3V Telemetry port. The amber LED will flash
continuously, indicating the receiver is in bind mode.

WARNING: Do not power the SR3300T
through the LAP, TEMP, or RPM Port the
receiver will be damaged

So it goes I wouldn't draw power either and you'd only get 3.3v