If you can assign a tracker at all in broadband, chances are you've already got one or two lines in narrowband, that's why you use narrowband. But there is a variance on this for narrowband use:
If you move your cursor across the narrowband bearing screen about 5 degrees at a time, you might not see any lines but the class filter will come up anyway. When this happens, you can try moving the frequency cursor to match one of the lines on the filter screen and click "assign tracker". Sometimes this will get you your contact before you can see any frequency lines.
I find this works more often with American boats but it also works with the Akula and others. Any edge you can get right?
