[Elecraft] KXBC3 clock drift

[VE2PID]

....

Looking at the schematic of the KXBC3, the real time clock seems to be a 
part of chip PIC24F16KA10.
And a reference to that chip says this:

29.3.9     Calibration
The real-time crystal input can be calibrated using the periodic 
auto-adjust feature. When
properly calibrated, the RTCC can provide an error of less than 3 
seconds per month. This is
accomplished by finding the number of error clock pulses and storing the 
value into the lower half
of the RCFGCAL register. The 8-bit signed value loaded into the lower 
half of RCFGCAL is
multiplied by four and will be either added or subtracted from the RTCC 
timer, once every minute.
Refer to the steps below for RTCC calibration

(Reference: http://ww1.microchip.com/downloads/en/DeviceDoc/39696b.pdf )

So I wonder if some calibration could be done via a software mod. My 
KXBC3 clock gain about 15 seconds per week ... far away from 3 seconds 
per month ... ??

73 de Pierre VE2PID KX3 s/n 190