Locked Frequency Cal - WHY?!

K9RX - Gary

Ok ... This is for the designers please:  forgive my questions. WHY do I need to frequency calibrate? I know, I know - it says its needed because it has to be within 1 hz for FT8... but are signal TX frequencies quantified? I.e. If I select 14.074201.6 on the radio (just a number) - is WSJT going to "move it" to 1.0 or 2.0 or ? If not - if whatever I set it at that is what is used then why do I need to calibrate since it is then relative? 

Stated another way - there's nothing "magical" about say 14.074.000 ... if I have a TX bandwidth selected at 2.8Khz starting at 0.1 and someone is at 2.95Khz I can just tune my radio up 200hz and bingo he's in my passband - so once again: why calibrate? 

I seriously thought my Anan running PowerSDR was pretty darn accurate re frequency, I had it within less than 1 Hz at 15Mhz ...  yet when I run the test its off by 10.1Hz at 20Mhz! I ran the test and did a calculation and set the parameters and now I'm at +0.1 at 10Mhz, -0.35 at 15Mhz and +0.1 at 20Mhz (not a straight line so can't do any better) .... but what will be the result of doing this - will I literally see MORE decodes? 



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