[Elecraft] K2 A to B Kit - Frequency Stability Test

[Brian McCarthy]

I really tried to find these in the archives, but I am stumped.

In the frequency stability test one is directed to tune to about 7182 
KHz , activate the built-in frequency counter, and then check TP1 (VCO) 
and TP3 (PLL reference osc.), "and make sure they indicate the same 
frequency..." To what level of precision is considered equal? To put it 
another way, my K2 (s/n 711) has about 0.03 to 0.04 KHz difference 
between the two across the approximate range. That's not exactly equal, 
but it is roughly equal. What is "equal" in this case so that I can 
determine the range correctly?

Yes, my real job deals with precision into microns.

On a related topic. I have an HP Z3801A GPS disiplined clock with a 
10MHz reference output. It seems a natural to feed that output into the 
frequency counter probe for the adjustment of C22. I forget the output 
voltage of the HP (1 volt?), but I will look it up...What is the 
advisable voltage input limit of the K2 frequency counter probe?

Thank you,
Brian
NX9O