RTTY (?) on top of WWV, 10mHz

[Chanter]

At around 0010Z tonight, April 22, I happened to flick to 10mHz.  I could hear WWV, but atop it was what at first sounded like their two-minutes-past-the-hour tone.  I checked my watch to confirm what I already knew... nope, not 0002.  A little further listening, including a shift to sidebands and back to AM, got me a transmission that sure sounded like either RTTY or some other goofy fax mode.  What's up with that?  Has anyone ever heard this or similar before?  And maybe most importantly, why the heck would someone put an RTTY transmission on top of a known time signal frequency? 

[staticlistener]

I'm hearing it here too, I think I've heard the same thing before on that same frequency.

[Chanter]

The RTTY weirdness seems to be gone as of now, 4/24 by UTC.  Must've been a transient thing.  

Posting to report that much, and to get that nasty number off the post count indicator for this subforum!  667, whew!  

[07code04stalker1776]

At around 0010Z tonight, April 22, I happened to flick to 10mHz.  I could hear WWV, but atop it was what at first sounded like their two-minutes-past-the-hour tone.  I checked my watch to confirm what I already knew... nope, not 0002.  A little further listening, including a shift to sidebands and back to AM, got me a transmission that sure sounded like either RTTY or some other goofy fax mode.  What's up with that?  Has anyone ever heard this or similar before?  And maybe most importantly, why the heck would someone put an RTTY transmission on top of a known time signal frequency? 

One Idea (However I don't believe that this is the case) is that this frequency is a constant TX Frequency, thus a good way to determine if you (as receiver or monitor) are receiving on the correct (or close to correct) RX Target frequency. I feel that for example 4625 "The Buzzer/S28/UVB-76" Has a buzzer that sounds just about close to every second. Every once in awhile on S28 there is a coded message given at a random time and interval. I like to try and think that this could be a cool coded RTTY message, but I doubt it. All I am saying is this could be a Radio Frequency landmark (However I feel not likely), the TX station could over power locally WWV, or the TX and RX station are out of range or in the skip zone of WWV, they could be on the wrong freq, etc. There are a lot of possibilities. I feel that most likely it would be a slightly off frequency RTTY station however I feel that you could be right about it being on frequency. Do you have an audio sample from that time?

[Chanter]

Alas, I don't have any audio from that time.  I'm going to bet it was a one-shot RTTY transmission; either someone fooling around, or a station off its usual frequency.