On Chroma Dots and how to determine if they are present

[VintagePC]

OK, here's the effect I'm seeing (that background is a saturated blue in colour).
Also... looking at the text in the first image... is my picture tube under-focused (i.e. focal point behind the phosphor face)? The scanlines seem to expand to a larger "blip" when the brightness is turned up.

(clickable for full-size)



And another with a "real" image - visible on the hand/glove



It's a little fuzzy since my camera doesn't like the TV screen and wants to use the flash but I won't let it.

I'm pretty sure this isn't audio carrier as I experimented with tuning off-channel and I can see what old_tv_nut is talking about - especially on channels with just speech since there are naturally periods of silence and the effect will come and go with the sound.

Looks a decent match for what Bob posted earlier but not as pronounced, so if anything I suspect either IF alignment is a bit off, or the bandwidth is just barely wide enough to let some of that effect bleed through.