Re: ubitx circuit, wiring, source code on github

Gordon Gibby <ggibby@...>
 

Thanks, jerry --- 


He seems to have two completely different calibration scenarios in the sketches:


1.  Factory calibration, where he turns off all  oscillators except one and has you calibrate via  10MHz synthesized signal, and THEN set were the bfo oscillator is on the skirt of the filter;    (see ubitx_factory alignment file) 


2.  User calibration, accessed through normal usage of the encoder push button, where he seems to work at keeping you tuned into a friend as you fix your frequency display (adjusting internally both oscillators in compensatory ways?) and then separately set the BFO to desired portion of the skirt..

(see ubitx_menu file) 


In the outcome of both techniques, I think  because of the way he calculates local oscillator frequencies, that the displayed frequency setting remains accurate even if you move your choice for the BFO frequency, via the code below:



void setFrequency(unsigned long f){
  uint64_t osc_f;
 
  setTXFilters(f);

  if (isUSB){
    si5351bx_setfreq(2, SECOND_OSC_USB - usbCarrier + f);
    si5351bx_setfreq(1, SECOND_OSC_USB);
  }
  else{
    si5351bx_setfreq(2, SECOND_OSC_LSB + usbCarrier + f);
    si5351bx_setfreq(1, SECOND_OSC_LSB);
  }
  
  frequency = f;
}






From: BITX20@groups.io <BITX20@groups.io> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Sunday, December 31, 2017 1:47 PM
To: BITX20@groups.io
Subject: Re: [BITX20] ubitx circuit, wiring, source code on github
 
Source on github at   https://github.com/afarhan/ubitx
appears to agree with this Dec 6 post from Farhan  https://groups.io/g/BITX20/message/35241
regarding how to calibrate the Si5351 on the uBitx.

But the write up at  http://www.hfsignals.com/index.php/ubitx-tuneup/
appears to agree with this post:  https://groups.io/g/BITX20/message/35235

My guess is that Farhan's github repository is out of date
and does not agree with what is getting shipped.

Jerry, KE7ER

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