How to delete rows, if a column has a non-duplicate. LibreOffice Calc

Hello, I have a spreadsheet of a lot of repeaters (ham radio) I would like to be able to find the same repeaters for two different locations.

What I would like to do in LibreOffice Calc is for it to find NON duplicates in column B, and if it does find a non-duplicate to delete the row that contained that information. . If it is at all possible it would be nice to delete the row itself so there is no gaps between the entries.
*The non-duplicate that I would like it to find is the name of the repeater so it is not constant

Repeater names are not entirely consistent in my neck of the woods; you might also want to sort the list by frequency, then step through the list and make comparisons to look for possible deletes. 73s & best regards.