Topband: WWVB reception

[W2pm at aol.com]

I am amazed that a 15.00 MFJ "Atomic clock" which has a built-in receiver for 
WWVB at 60khz works here in NNJ.  Reception of the 60Khz signal was a bit 
spotty in the summer depending on the location in my house, however since the 
fall the signal is consistent 24 X 7.   

I believe WWVB runs about 20KW but given they are over 1700 miles from here 
and the difficulty my modest 160 station has on receiving 1.8 and below signals 
from that far without fairly elaborate methods - what makes this cheapie MFJ 
device work so well??   Has MFJ invented the ideal low band receive antenna or 
is there something special about propagation that low in frequency?

73 Pete, W2PM