[Elecraft] PLL/BFO Stability Mod

[Lyle Johnson]

> ...the d is normal.  Exactly what it means, I am not sure,

The "d" is fully explained in the Version 2 firmware manual, page 4, VFO Cal
section, item 5.  It is also in the Rev D manual (for units above serial
number 3000) on page 60.

> I also get the little 5KHz 'glitches' but they are very
> mild and are not present everywhere. I've never found them a concern.

If there is a signal present in the passband as the VCO steps at the 5 kHz
points (not necessarily at the xxxx5.00 kHz or xxxx0.00 dial readings) you
will hear a slight "pop."  The loudness of it depends on the strength of the
signal as the VCO steps through it, your filter bandwidth at that time, etc.

My K2 had this problem even with no signal present.  I put up with it for a
long time, assuming it was normal behavior.  Last October, I did the PLL
mod, change to one crystal, etc.  I didn't then have a crystal with enough
"pull" so I re-installed the old crystals - and the symptom went away!  I
concluded that, in spite of appearances, there must have been a soldering
problem (or the old crystal just needed to get good and hot?).

I have since performed the PLL mod with the correct crystal and the K2 works
properly.

If you are having the symptoms I was having, and your soldering is good, I'd
suspect the crystal in the PLL reference oscillator circuit.

73,

Lyle KK7P