[Elecraft] K2: Is there an ideal power supply voltage?

[Andrew Moore]

While the K2 is capable of operating from a range of input voltages, is
there an ideal power supply voltage it prefers to see for best receiver
performance? If so, what is that voltage (as indicated on the K2 LCD when
"DISPLAY" is pressed twice)?

Would the K2's receiver performance benefit from a realignment (filters/BFO,
IF, 4.0 MHz oscillator, etc.) after the power supply voltage is change? (as
impractical as that may be in real life)

Thanks,
--Andrew, NV1B