[Elecraft] K2 alignment after removing X2 (Logic Check?)

[k6se@juno.com]

Randy, KS4L wrote:

"I've only been sorta paying attention to this thread, but just now
looked in my K2 construction manual, Rev. A and found that the range for
the BFO test is 3.5 kHz to 6 kHz.  When did this change?  Is removal of
one of the xtals still viable for my K2?"
==========
I'm glad you brought this up, because I consider BFO drift in the K2 to
be a more serious problem than PLL Reference oscillator drift.

Like you, I am also highly interested in hearing if anyone has removed
one of the BFO xtals to increase BFO stability and successfully
alleviated the problem of received signals drifting in and out of narrow
CW filter passbands while the temperature changes.  This is the worst
problem with my K2, making it virtually unusable on CW.  My K2 now
gathers dust in a corner of the shack because of this (wide filters don't
afford good enough S/N for receiving weak signals).

I don't know when it changed from the Rev. A manual, but the Rev. C
manual says that the BFO must be able to cover 4912.7 kHz to 4916.3 kHz,
or a range of at least 3.6 kHz.  The manual says, "Typical range is 4 to
6 kHz".

In case BFO range is adequate but the frequencies are shifted too high or
too low, the manual suggests, "If you didn't calibrate the K2's internal
frequency counter, it may not be reading accurately.  If possible, borrow
an accurate counter and re-do the 4 MHz Oscillator Calibration".  I
highly recommend Tom's procedure of zero-beating the 4 MHz oscillator's
5th harmonic with 20 MHz WWV as an even better method calibrating the 4
MHz oscillator.

73, de Earl, K6SE