[Lowfer] 950 kHz time signal?

[Dexter McIntyre W4DEX]

While turning across the AM BC band I heard a CW "RR" signal on 950 kHz 
mixed with multiple BC stations.  Listening to the frequency for a while 
I determined the RR followed a brief tone dead on the top of each 
minute  along with a time tick each second.   This was received on a 
R-75 receiver so I switched to a SDR-IQ and heard the same signal.  The 
signal fades in and out like normal MF QSB.  Here's a screen capture 
showing the tone and the CW RR:

https://dl.dropbox.com/u/15095569/w4dex/950khz.jpg

? 

Dex