[Elecraft] VCO relationship with 4 Mhz ocsillator

[Jean-François Ménard]

Sorry to bother you....

I read in my ARRL handbook about PLL... and now I understand that the 
PLL must have a fixed, precised, reference to phase lock it's loop.... 
the 4 Mhz oscillator clock...

I will find the place to put my scope probe to see the 4 Mhz oscillator 
also... just for my understanding.

Thanks and sorry again for your time.

Le 04-11-25, à 19:49, Jean-François Ménard a écrit :

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

Elecraft K2 #4130

http://homepage.mac.com/jfmenard
===========================