[Chip Chester]

He has a real (nice) Tek waveform/vector scope combo, and as I recall it has looping inputs for A and B. Some of the newer ones were "self terminating", I believe by a little switch within the BNC connector. No looping connection=terminated. Looping connector installed=unterminated. Trouble is, sometimes they didn't actually switch (Sony!) so you had to add a terminator anyway.

But in general, that scope can be configured to show the truth about a composite analog signal. And bars in his first shot look good. I'd wager either misadjusted unit (perhaps curable via menu), bad cable, or his stated suspicions about the device quality are justified.

Chip