Yesterday I received my new uBITX v6 full kit and assembled it. After a short function check (could hear some CW and FT8 signals), I installed CEC firmware and Nextion display. Everything worked right out of the box, but later I noticed, that when I tune to CW signals, the audio tone is very high. When I tune the HF for strongest audio signal, the audio tone is around 5khz, and when I change the frequency to get the tone lower, the signal disappears before getting down to the range of 1kHz.
For testing, I tuned to a strong CW station in LSB, USB, CWL and CWU. The highest volume for each mode was approximately:
7029 kHz LSB
7033 kHz CWL
7023 kHz CWU
7025 kHz USB
With SSB modes I can tune the tone frequency down, but also the signal is stronger at higher frequencies than 800Hz.
So far, I didn't do any calibration, and right after uploading the CEC firmware, I downloaded the eeprom data with the ubitx manager software.
Could this be a frequency or bfo calibration issue? Im not sure, because it is mostly a problem in CW modes, and I thought the boards come calibrated from the factory.
Should I go back to the stock fw and display to run the calibration procedure of the V6 firmware with the web spectrum analyzer tool?
Something else to check? I have an HP/Agilent Oscilloscope, but the last calibration of that was 2003, so not sure how accurate the frequency counter of that is.
Thanks for help,