RF Antenna

No, they don't sell antenna's seperate.

You can get any antenna from say Radio Shack that has a "f" connector on the end.... Or you can try to make one.

For what receiver? The H20 or the R15 are the only ones that would need an antenna. The HR20 has a built in one.

My mother wants one for her R15. Will ANY antenna with an F connector work? I have quite a few lying around.

As has been mentioned on other threads, a short length of RG6 with an F connector attached and the braid and foil stripped back would work, as would a bent paper clip.