Frequency Measurement Test -

Mike-VA3MW

Robert Lonn

Bill W2PKY

John KB4DU

Logan KE7AZ

Bill W2PKY

When you do the radio calibration function the -ppb value is applied to the master VFO. The GetERROR API result is the error developed from the truncated tuning word. The -ppb error value does not enter into the calculation for the FMT.

John KB4DU

OK. TNX. Still setting up a process since the 6400 doesn't respond to geterror.

k3Tim

I would not worry about the GetError() to much as the propagation throws the frequency off more than this component.  Granted, averaging the frequency overtime should reduce the error due to propagation but sometimes it seems to have an offset.

In fldigi frequency analysis mode, one can open the floating scope and watch the propagation effects on the frequency, especially with WWV.

Mike-VA3MW

The GetError only works on the 6500, 6600 and 6700.  It will respond with a value on the other models, but the number is a garbage number.  (see page 7 of Ron's document)

Bill W2PKY

Jim KJ3P

Yes...the FCC frequency tolerance for AM stations used to be +/-20 Hz, so station engineers don't usually don't worry about being exactly on frequency.
---jim KJ3P 

Robert Lonn

I use an external 10 MHz GPS clock, so I decided to check it and it was -.9 PPM, , when I went on the internal TCXO it was -1678 PPM!! So with it locked to my GPS Station Clock,, probably good enough for government work!!! :-) "Can You Hear ME Now!"