20 week breakout

Data elements inside a function (high, in this case) also need the time frame modifier. The scan engine always assumes you mean "daily" unless you say differently.

Also, to be consistent, you want a weekly volume number as well (so you might want to jack up the number, depending on what you are looking for).

[weekly volume > 300]
and [weekly high > weekly max(20,weekly high)]

Now that I look at the logic and not just the syntax...

You get no results because the condition cannot be true - if this week's high is the max, it can't be greater than the max, only equal. If another week's high is the max, this weeks' high can't be greater (or this week's high WOULD BE the max).

So, you need to compare this week's high to the 1 week ago max high - like this:

and [weekly high > 1 week ago weekly max(20,weekly high)]

One way to do that would be to test for a channel break after the channel has been flat for some number of weeks. For instance

and [weekly high x weekly Upper Price Chan(20)]
and [1 week ago weekly Upper Price Chan(20) = 10 weeks ago weekly Upper Price Chan(20)]

You could change "weekly high" to "weekly close". You could change "10 weeks ago" to some other number (less than 20).

The upper price channel represents the highest price in the last 20 weeks - but that is not necessarily 20 weeks ago. The highest price in twenty weeks might have occurred last week or five weeks ago or fifteen or 20 weeks ago. Using "10 weeks ago" insures the highest price in the last 20 weeks was at least 10 weeks ago - maybe more. If you play with that number you can see what length of straight channel gets the kind of results you want to work with.