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old calibrating uBITX

 

Hi everyone, I built a uBitx v5 (so 11.059 filter) from scratch only receiver. I know it's an obsolete and trite topic, but I wanted to ask you if there is a good method to calibrate its VFO and perform the calibration. I've read a lot of things, but I can't do it optimally.
I have calibrated the frequencies output from the raduino via software. But the receiver I just can't understand the logic.
I hope to receive some safe suggestions, to then transfer it to a container.
Also, the VFO calibration and calibration, must be done on an amateur radio frequency or on a commercial one (also much debated)?
Thanks and 73 by Antonio IU7SUX
 

 

Hi Antonio,
?
What software are you using for the Nano?? That can influence the calibration method.
?
Since it is receive only, zero beating is the best solution that I know of.? Any known CW, AM, or FM source in the receive area can work.? Tune the radio to the signal source frequency (I use a known, accurate signal generator) and follow the general steps of:
1 - Adjust the BFO to receive the low-frequency audio tones by positioning the plateau to the left of the 300 to 3,000 Hz range
2 - Calibrate the Master frequency using the zero beat method
3 - Readjust the BO to center the audio plateau between 300 and 3,000 Hz.
?
Here is a v6 video to do the calibration:
?
The steps to turn on the BFO and Calibration functions in the Nano depend on the software you use.
?
The BFO tuning page from HFSignals is no longer functional.? I use a PC based audio spectrum analyzer to set the BFO:
or
?
73
Evan
AC9TU
?
 



On Sun, May 25, 2025 at 10:03?AM Evan Hand via <elhandjr=[email protected]> wrote:
Hi Antonio,
?
What software are you using for the Nano?? That can influence the calibration method.
?
Since it is receive only, zero beating is the best solution that I know of.? Any known CW, AM, or FM source in the receive area can work.? Tune the radio to the signal source frequency (I use a known, accurate signal generator) and follow the general steps of:
1 - Adjust the BFO to receive the low-frequency audio tones by positioning the plateau to the left of the 300 to 3,000 Hz range
2 - Calibrate the Master frequency using the zero beat method
3 - Readjust the BO to center the audio plateau between 300 and 3,000 Hz.
?
Here is a v6 video to do the calibration:
?
The steps to turn on the BFO and Calibration functions in the Nano depend on the software you use.
?
The BFO tuning page from HFSignals is no longer functional.? I use a PC based audio spectrum analyzer to set the BFO:
or
?
73
Evan
AC9TU
?
 

Evan thanks for the reply. I am using the K8CEC fw v.1.21 on 20x4 display.
The generator you are using, do you put it in AM modulation or pure sine wave?
Anyway I found the site https://itshamradio.com/bfo-tuning-aid-ubitx/, where there is the same app as Faharan
73 IU7SUX
 

I use the single frequency sine wave.?
 

Very good, well done!
I save the page for future use.
73
 

Ok i try this, becouse in my lab I don't have an antenna.

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