I found by accident that the Uniden BCD396XT and the SDS-100 both go down to 25.0 Mhz. and subsequently can recieve WWV very clear using my discone! I'm sure there are other Uniden's also. My Whistler TRX-1 also works. I remember they added 25 Mhz. to the list of WWV transmitters a few years back. I never thought of trying it in the scanners.