There are some things that just can not be fixed by messing with the transmitting end of the problem. That's usually because the 'problem' is at the other end, the receiving end. It depends on who made the receiving device (TV), and when, and who knows what else (you'll find that in the interference handbook, by the way). That sort of thingy can be 'fixed' by some judicious and 'non-intrusive' additions to the neighbor's TV, some times, as in a high-pass filter. Another part of that that can't be fixed 'non-intrusively' is by providing adequate shielding to that TV. Or in effect, move the TV further away from the source (can also means moving your antenna too).
Antennas radiate in all directions, even the directional ones. The closer you are to that antenna the more of that "spill-over" signal you will get. The only reasonable way of getting rid of that 'spill-over' is to get further away from it, it's strength drops off pretty quickly, sort of. If possible, try moving things a bit and see what happens. At the distances you normally find a neighbor, that 'moving things' isn't exactly always practical. So, putting up with it is about all you can do.
The 'catch' to all these FCC regulations deals with CB not being a licensed service. Which means that it has no protection from receiving devices that aren't exactly the best in the world, that pick up any stray RF that happens by. Doesn't matter if the interfering signal is the cleanest in the world, or the dirtiest. (See the rules for Part 95 devices, which TVs are.)
One clue about about if your neighbor's TV is the culprit is if your TV gets the same kind of interference. Does it?
And depending on how 'reasonable' your neighbor is (and how generous you are), sometimes it just isn't 'curable', which means that you are out of luck, and into court (ouch!). Been there, done that, you -=<REALLY>=- don't wanna go there even if they find in your favor, NOT fun!
Good luck.
- 'Doc
The reason for that 'non-intrusive' thingy is that if you mess with their TV then you are responsible for the problems encountered there after. If adding something to their TV can cure the problem, don't do it yourself, give the correcting part(s) to them and let -them- do it!
Read that interference book!