I can hear clearly now, the warble is gone...

More big strides made today on the software development front for the FLEX-1500. The Frequency calibration routines, Spur Reduction and the ability to fine tune the frequency of the radio by manually tweaking the DDS Clock Offset is now working.

My FLEX-1500 was off by about 15 Hz, which generates a noticeable warble in the receive audio when you listen to WWV in DSP mode. Now the warble is gone after running the frequency calibration.

I should note that these changes do not have anything to do with frequency stability, just the accuracy of being on frequency when compared to a reference frequency, like WWV. I should be receiving a Rb frequency standard in the next week and I plan to use it to calibrate and check frequency drift.