David Stinson wrote:

I, too am hearing Sam on 5 MHZ with a strong signal in North Texas.
This is almost certainly a covert "go" signal from our government.
Could be an exercize (most likely).
It's on WWV at 5 mHz because that provides a "BFO" for cheap SW
receivers.

Assuming 'they' is Uncle Sam, I wonder if they got approval from the
NIST or ITU to interfere with WWV? Probably not.