KD8CEC Amateur Radio

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How to Frequency Calibration on EU1KY Antenna Analyzer

Posted: 11 Apr 2019 06:21 AM PDT
http://www.hamskey.com/2019/04/how-t...-on-eu1ky.html

How to Frequency Calibration on EU1KY Antenna AnalyzerI will calibrate the
frequency of AA in two ways.
One is using the instrument and the other is using the SSB radio without
the instrument.To use an AA as a generator to test a radio, you must have a
calibration procedure. Also To use the WSPR, FT8 generator included in
Version 0.40, the frequency should not be too different.
1.How to calibrate using instrumentsFirst, check the XTal frequency on your
AA. Maybe it will be 27Mhz most like me.

In configuration, set Si5351_corr value to 0. Maybe this value will be 0 if
you have not tried setting it yet.
Important here.Does your instrument support XTAL frequency (27Mhz)? Then
set 27Mhz.(No need for a calculator.)
If the accuracy of your instrument is low? If so, set it to the maximum
value that the instrument can receive. (ex : 50Mhz, 70Mhz)
The higher the frequency, the greater the error generation, so the less
precise instrument can be quite accurate calibration.
I set it to 21Mhz to give an example. You can set it to any frequency.

Check the measured value of the instrument. In my case, measured frequency
is 21.003314018MhzCalculate the difference between your AA frequency and
the measured frequency.
Measured Frequency - AA (Generator) FrequencyIn my case : 21003314 -
21000000 = 3314hzI will call this value the error frequency.


In this part, you do not need this calculation part if you used 27Mhz. The
values calculated above can be used as is. If you are bored, you can
calculate it.
If you do not use 27Mhz (XTal Freq), calculate as follows.
(X-tal Frequency / RF Generator Frequency) * error frequency (Calculated
just above, in my case 3324)
Below is an example of my case 27000000 / 21000000) * (21003314 -
21000000) = 4261.8
My calibration value is 4261 (Round)
If you measured the frequency using 27Mhz, you would not need to calculate
it because of the formula below.(27Mhz / 27Mhz) * (error Frequency) = 1 *
(error Frequency) = error Frequency

Enter the calculated calibration value in SI5351_CORR.In Version 0.35 and
later, a + - 200Hz button has been added to allow for faster input.
The two pictures below are in my case.
It can be seen that it is accurately set to less than 1 Hz.However, the
higher the frequency, the greater the error.
Test by increasing or decreasing the frequency by 1Hz.
Video


2.How to calibrate using SSB Transceiver with your cell phoneFirst, check
the XTal frequency on your AA. Maybe it will be 27Mhz most like me.
In configuration, set Si5351_corr value to 0. Maybe this value will be 0 if
you have not tried setting it yet.

Important here.Does your SSB Transceiver support XTAL frequency (27Mhz)?
Then set 27Mhz.(No need for a calculator.)
Or you can use any frequency.The higher the frequency, the greater the
error generation, so the less precise instrument can be quite accurate
calibration.
I set it to Xtal Frequency (27Mhz) to give an example. You can set it to
any frequency.
in RF Generator - Touch Frequency Button - Input Frequency
Now your AA is generating radio waves.
Please use the radio to receive radio waves from AA. USB mode is
recommended. LSB does not matter, but the method of calculation is slightly
different.

When you start to hear the sound, take your cell phone out.
Your phone must have an app that can view Spectrum. It is mostly free.This
app shows the spectrum of notes coming through the microphone.
That kind of app is on both Iphone and Android. It does not matter if you
like what you like.
I use an app called spectroid.
Try adjusting the frequency of the transceiver until the sound from the
transceiver is 1 kHz.




I set it to 1Khz.
Now check the frequency of the radio.In my case : 27.003260 Mhz
Please subtract the frequency of AA from the frequency displayed on the
transceiver.In my case : 27003260 - 27000000 = 3260Add 1000 to the above
value.In my case : 3260 + 1000 = 4260 (error Frequency)
If you were using 27Mhz like me, the following calculation is not
necessary. The error frequency shown above is your calibration vlalue.

If you do not use 27Mhz (XTal Freq), calculate as follows.
(X-tal Frequency / RF Generator Frequency) * error frequency (Calculated
just above, in my case 3324)
Example)If your frequency was 50Mhz, it would have been calculated as
follows. 27000000 / 50000000) * (4260) = 2300 (Your calibration value)
If you measured the frequency using 27Mhz, you would not need to calculate
it because of the formula below.(27Mhz / 27Mhz) * (error Frequency) = 1 *
(error Frequency) = error Frequency


Test by increasing or decreasing the frequency by 1Hz.
Video



3. conclusionI had previously posted the Si5351 calibration method on the
uBITX (QRP
transceiver).http://www.hamskey.com/2018/05/frequ...tx-si5351.html
If use the method of correcting the PLL frequency of DDS, it will be more
accurate calibration. I will fix the firmware for Calibration later if I
need more accurate frequency than AA.But this is quite useful for making or
repairing a transceiver.

Thanks for readingIan KD8CEC