Half finished  This article like many Wikipedia seems to be pretty good technically at least in some ways but there seems to be a lot missing What this article really needs is a proper TV engineer to write at least a section for it I could be persuaded to do this but I would have to do a lot of research first and I havent touched the subject for about ten years  But there needs to be a section about comb filters in television systems and other analogue electronics  Anyway in analogue TV the comb filter isnt a small peripheral component of the system its actually pretty much the heart of the whole decoder As I remember It is the comb filter that breaks the signal up into components and it does a kind of magic that allows a very simple circuit to do a very complex task In fact I seem to remember that it is use of comb filters that made the whole analogue TV system possible  I also suspect that the description of comb filters based and focused on delays is only partially correct or complete it is more of a simplified scientific rather than an engineers explanation has a lot of math and may actually confuse people Yes comb filters can or do use delays but the essence of the filter is that it is recursive a repeated element  another name for them I have heard is recursive filters  Also I dont think the shape of the waveform is the place the filter got its name from its circuit diagram actually looks like a comb or matrix made of resistors but I think the name came from a more abstract level  the filter orders in a certain way it was originally concieved as like a comb  it just happens that the waveform looks the same because that is what it does   The delay based version of the circuit is only one type and there are others In fact I seem to remember reading somewhere that comb filters are considered a universal type this means that combs can be made to perform almost any function and also that almost any given circuit type can be made to work as a comb This was probably from an early book on cybernetics or feedback computation or AI my own main subject area   The final thing not mentioned is the inventor of the comb filter who I think may be someone like Norbert Werner or one of his friends but this is purely a guess