RP-SMA is a "reverse polarity" SMA connector. It's not going to play well with your scanner without an adapter.
And as the others said, it'll "work", but not work well, unless you really want to listen in on 2.4GHz and 5.8GHz.
I wouldn't pay for one, but if you've got one laying around and the correct adapter, you could certainly give it a try. There really are better antennas out there.