I got a new AM21 delivered yesterday that I had ordered about 2 days ago, it comes with the extra power cord.
Having received mine today, I can confirm that the DTV OTA tuner package contains ALL of the following:
1. the tuner, either AM21 or AM21N. I have no idea what the differences are, beyond the exterior cosmetics. AM21 is gloss finish and says "AM21 off air tuner" on the front bezel. AM21N is flat black finish and says "off air tuner" on the front bezel.
2. a power cord, so that the tuner can itself plug into 115v without steeling the power cord from the receiver to which it is married.
3. A protective CAP, to be installed on the unused pigtail power cord that is permanently installed into the tuner and normally supplies power to the DTV receiver who's power cord is stolen in (2) above.
per the instruction sheet "All AM21s are being retrofitted to include the electircal cap and a power cord. The AM21N has a power cord included in the pack out. If an electrical cap is not installed, request another AM21/AM21N that has one."
4. an instruction sheet ambiguously and incorrectly describing the way power is distributed between the tuner and the receiver: "The AM21/AM21N typically obtains power (110VAC) from an HD/HD DVR Receiver ..." wow, they got that so backwards...