Re: Erratic tuning with my new uBitx

Ian Lee

You have given the opportunity to add another great feature for uBITX Users.
Thank you.

I do not know about your External Filter. But I know that you are doing a great job to improve your uBITX.
If you have a spare time, please introduce your External Filter. I want to make it.
I do not have much experience with such things, so I do not know if it will be the right answer.

I think there are three ways you can solve your problem.
1.Adjust the Master Calibration.
  If you use uBITX Manager, do not worry.
  Before making any adjustments, uBITX Manager can back up your uBITX information to a file.
  If you have a backup file, your uBITX can be restored at any time.

  I think you can lower your Master Calibration value a little.
  If you let me know the reference frequency (EX: 7.02Mhz, 14.03Mhz ...) you used to measure in the frequency counter, I will give you a calculation.
  If you send me your uBITX backup file, I can look into it more closely.

I'll skip it, Because you measured the 150hz error clearly through the instrument.
2.Adjust BFO
3.using split 

 Also, if you prefer to modify the code rather than the calibration setting, add 'calibration = calibration - 00000' to the end of the initSettings () function.
 Instead of 0000, try increasing the value in small increments.


2018-04-23 1:29 GMT+09:00 Chris Clarke <csclarke@...>:

Hi Ian

I'm compiling, uploading and running v1.070 and I still have one  issue.

I suspect I must have a calibration problem, because in order to achieve a 600Hz CW TX off-set (to match my external 600Hz AF filter) I have had to hard code the call in <ubitx_20>  at line 647

si5351bx_setfreq(2, frequency - sidetone + 150) ;

I have checked the TX frequency with a my frequency counter and it is definitely off-set from RX by nearly 800Hz when <sideTone=600>, and is correctly offset with my addition of 150.

If I just change the value of the variable <sidetone = 450>, the TX offset is then correct but the audio tone frequency is way too low for comfortable listening on RX.

With <sidetone = 600> the audio sounds perfect, however the extra 150Hz TX offset applied by the call <si5351bx_setfreq(2, 600)> takes the received signal outside the passband of my external AF filter.

Can I change/calibrate one of the program parameters/variables to achieve the same end?

I am wary of doing anything via the calibration menu without being sure of not doing something irretrievable. Eg calibrating BFO could have implications I am unaware of, as this is not the simple BFO of which I am familiar from my 1960s analogue receiver days!

The problem was the same with earlier firmware versions (eg v1.061) so am I correct to assume that this is a hardware issue requiring calibration in some form?


Best 73
KD8CEC / Ph.D ian lee
kd8cec@... (my blog)

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