[Elecraft] [P3] XG2 Readings on the P3

[Rick Prather]

I am solidly in the "A little bit of knowledge is a dangerous thing" area here!

I hooked up my XG2 and set up my K3 as called for in the "S" Meter calibration section.  K3 has been calibrated with the XG2 to read S9.
 
With the P3 connected I expected to see something in the range of -72 dbm.  Instead I see -82 dbm.   

Am I expecting too much from the P3 calibration or am I missing something else?

TIA,

Rick
K6LE