This is from the datasheet for the TDA8217 PAL decoder and video processor. This is the "Applicaton Diagram".
The circled item is unfamiliar to me, I asked at my local electronic components distributor and no-one there recognized it either. It looks like an inductor, but seems to be connected to ground maybe?
Best Answer
Note how it says "330ns", a proper inductor would have a value in Henries.
My guess is that this is an Analog delay line like this:
Note how it has 3 connections of which one is ground which is connected to the tube and the shield.
I actually came across one of these many many years ago, probably in some video equipment I scrapped for parts. At the time didn't realize it was a delay line.
The "330 ns" and a search for "delay line" led me to the Wikipedia page. The delay line in the picture has 450 ns delay so 330 ns looks like that could be achieved with a similar component.
Sidenote: there are also Piezo electrical delay lines (see an example here) used in analog video equipment and I have seen lots of these and most have a 64us delay time which relates to the old PAL television standard (64 us is one horizontal line of the image). But 64 us is much larger than 330 ns so I knew that these were different types.