It is possible that you're receiving YVTO. Try listening in SSB to see if you
can pick up an ID, which usually lasts quite a bit longer than WWV's.

73s
Ken Maltz
Jericho, NY
NRD-535D, NRD-220 Collins R-388, Racal RA6790/GM,
ICOM R71A, ICOM R-7100(x3), AOR AR-8000
Panasonic RF-2200, Sony ICF-7600GR,
Hoka Code3 Gold-Pro, 60' long wire, MLB balun