[Elecraft] VCO relationship with 4 Mhz ocsillator

[Jean-François Ménard]

Hi,

As a newcomer in amateur radio... I don't know much about electronic... 
But one thing for sure... My K2 works great !!!

I finally found today clear and easy explanation on the Internet of how 
SSB reception works and the relationship between all components in the 
block diagram of a simple one (1) I.F. receiver.

Could someone tell me the short story about the relationship between 
the PLL reference oscillator and the 4 Mhz oscillator from the control 
board ???

I'm asking this question because when I calibrate the PLL reference 
oscillator at TP3 using the internal frequency counter of the K2 and 
also using my external Instek frequency counter also connected at TP3, 
trying to match the K2 PLL frequency on both display.... Well.... I'm 
turning C22 on control board, associated to the 4 Mhz oscillator.... 
and that make the PLL oscillator to change.... Why ?!?!?

I can see the on the control board that the MCU have an output /PLLCS 
that go to the PLL synthetizer.... that must be there, but why ?

This setup seems to be particular to the K2 concept ?!?!? Right, wrong 
!?!?

Thanks for your time...


Sincerly,

===========================
Jean-François Ménard / VA2VYZ
va2vyz at arrl.net

Elecraft K2 #4130

http://homepage.mac.com/jfmenard
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