[Elecraft] PLL ref Osclllator range test

[James T. "Jim" Rogers]

Ken wrote:

Am putting my K2 together, and have a question on the Alignment test, Part
II,
PLL Reference Oscillator range test. What I am getting is a high of
12,100.37,  low of 12,081.51
thats about 18.56 Khz, about 3 Khz high by the manual, any suggetions ??

Ken, I just spent some time this afternoon trouble shooting that circuit for
another K2 builder. If the VFO linearization worked and if you measure the
control voltage out of DAC U5, I believe, and it is in specification, I
would say your crystal is just a bit more "rubbery" than some. Try to get
crystal from different manufacturing lots is not easy. Check the control
voltage out of the DAC on pin 7, that will be a true reference because it is
programmed by the MCU.

Ain't this fun!!!???

73,
Jim W4ATK
K2 #4028