[Elecraft] K2 #2894 complete, need some help tho

[Lyle Johnson]

Hello Andrey!

> The second thing is when i rotate the vfo dial to scan thru the
> frequencies, from time to time i can hear a "pop" and the s-meter
> jumps briefly to S5+ (even with the antenna disconnected). When i
> change the step to and start scaning slowly i can narrow the
> "pop" to a change between certain frequencies (10Hz step), but
> the "pop" occurs only during the change (its not like a signal
> that i am going thru very fast). There are few places wirthin the
> 40 m and 20 m bands where this occurs. ( I still dont have time
> to check the other bands)
> Any help will be appreciated!


The VFO system in the K2 uses a phase locked loop that steps every 5 kHz.
In between the 5 kHz steps, the PLL reference oscillator is pulled to create
the fine tuning steps (10 Hz, 100 Hz, etc.).  When a total of 5 kHz has been
tuned, the PLL is stepped to a different division ratio and the PLL
reference oscillator is stepped back to cpmpensate for the new, 5 KHz
different frequency.

So, every 5 kHz there is a quick "jump" in the K2 VFO.  If you have a signal
in that 5 kHz region, it will be heard as a "pop".  The louder the signal,
the louder the pop.  If AGC is ON, you may see it on the S meter.

73,

Lyle KK7P