Flex6500 GPSDO and FLDIGI are killer FMT app.

Andrew VK5CV

The title says it all. With the Flex 6500 and FLDIGI frequency analysis mode I can measure frequency to 2 decimal places! Andrew de VK5CV/VK5ZUC.

Robert -- N5IKD

Can you illustrate this with a screenshot?

Andrew VK5CV

Robert, 13MHz TCXO in frequency counter. Andrew

Sergey R5AU

Well Andrew, FLDIGI freq = RF Freq + Audio freq from waterfall

Bob N7ZO

Although the RF sampling rate is very accurate with the GPSDO, do we know that the effective sampling rate of the 6000's DAX output audio is as accurate?

If everything inside the 6500 or 6700 is clocked from the same master oscillator this is probably true, but I can imagine designs where output audio resampling occurs using another (and less accurate) clock domain.

I ask because I am also interested in FMT without having to use external hardware.

Bob N7ZO

Another issue I just noticed from another thread.  Tim reports "The specifications of the FLEX-6000 is to report frequency in 1 Hz increments."  What is the actual accuracy of the synthesized frequency?  It is unlikely that the frequencies lie right on the integer boundaries.

Sergey R5AU

Hi Bob, in the installation package of the MIxw32 - > http://mixw.net/, exist small apps for checking sample rate of audio device (48kHz supported),
sorry screenshot on rus:

Andrew VK5CV

Sergey

I have been running Check SR for a while.

-30ppm and -20ppm input and output so 50ppm all up

On the 10MHz GPSDO output I get 999999.94.

6parts per 10E9 total

GPS SSDR 5 e-11 estimate on the setup screen

thus DAX ( and FLDIGI?)  60pp10E6

Good enough for an ionospheric path.

Andrew

Andrew VK5CV

Sergey R5AU

Hi Andrew, you is right, this radio support reception from universe :-)
my GPSDO estimation on setup screen depends on time of the day  from e-10 to e-12 :

Andrew VK5CV

And FLDIGI lets me add a 60 ppm correction.