ARRL Frequency Measurement Test - Nov 8 0200 Z (that is Thursday Night ET)

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Hey all

If you have never tried it, the ARRL Frequency Measurement Test is on the evening of November 7th, Thursday night.     http://fmt.arrl.org/

It would be awesome to have a whole bunch of Flexers submit their measurements.

Years ago, I was able to do sub-hertz measurements with nothing more than a 6300 and using the FreqCal part of WSJTx.  https://www.physics.princeton.edu/pulsar/K1JT/wsjtx-doc/wsjtx-main-2.0.1.html

If you have a GPSDO or a 10Mhz reference OSC, you have an amazing piece of test equipment and should have no issue reporting less than 1hz of the exact frequency.  The procedure is well discussed here:  https://community.flexradio.com/flexradio/topics/arrl-fmt-tonight-getting-the-most-accurate-frequency

Now is the time to practice on WWV and some AM Broadcast stations and ask questions about how to make it work.  

This is the schedule.

0200Z-0520Z Nov 8, Submit Measurements by 0200Z, Nov 11

K5CM 40m (near 7064 kHz)
0200Z Call up for 3 minutes
0203Z Key down for 2 minutes
0205Z End of run

K5CM 80m (near 3598 kHz)
0215Z Call up for 3 minutes
0218Z Key down for 2 minutes
0220Z End of run

K5CM 40m (near 7064 kHz)
0500Z Call up for 3 minutes
0503Z Key down for 2 minutes
0505Z End of run

K5CM 80m (near 3598 kHz)
0515Z Call up for 3 minutes
0518Z Key down for 2 minutes


0520Z End of FMT
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Michael Walker, Employee

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Posted 6 months ago

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Logan, KE7AZ

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Spectrum Lab is also a good tool. It can record lots of data for subsequent analysis. Plus you can run multiple instances with multiple slices. It does require some setup so practice early.
Logan, KE7AZ
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Michael Walker, Employee

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Logan

Do you have any basic steps that someone could follow who might want to try to use Spectrum Lab and what data they would record?

Would it be as simple to record the carrier with a 1khz offset so that at a later point, you can measure the tone?

Mike
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Logan, KE7AZ

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Here is a link to an excellent presentation that shows how to setup
Spectrum Lab and Flidigi.  It has step by step screenshots that show
exactly what fields need to be addressed.

www.ve2azx.net/technical/FreqCal.pdf

Regarding your question, Spectrum Lab has a data export function in the File menu
  
        File->Export calculated data (continually) 

This feature creates a text file of data that you have selected from the full spectrum. Unlike Flidigi, Spectrum Lab does not delete the export file when changes are made, it just appends to the existing file.

The text file can be loaded into Excel and the "text to column" function used to put the data into columns. The data is delimited by blanks.  From here you can do your analysis.

When you click this item, it brings up a screen that allows you specify what is contained in each column of a text file.
 
Here is a screenshot of an export file format that I have used.

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Logan, KE7AZ

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My response got truncated...  Here is the rest, hopefully.


This setup captures the strongest frequencies of a WWV signal: the carrier, 100Hz tone and the 500Hz tone.  The Flex is tuned to 10.000.000.  It also captures two test signals at 10.000.505 and 10.000.510.

For the FMT, I plan to put a slice/Spectrum Lab pair at each of the FMT frequencies minus 100 Hz.  That would put the nominal carrier at 100 Hz in the spectrum with the actual test signal, nearby.  WWV is a good signal to experiment with.

Good Luck with the FMT
Logan, KE7AZ
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Michael Walker, Employee

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Today, I was playing around and I can now see that my radio is only, wait for it:

R1|0|-19.073486,-9.536743

That is 19 milliHertz off frequency

I think I can live with that.  

I am using an external 10Mhz frequency reference.  

Now, to start practising with WSJTx and Spectrum Lab.

Mike