[Elecraft] K2 TUNE power reduction without ATU installed .

[Michael Carter]

Hi Steve,

There is no documented method to set a lower
TUNE power when a non-Elecraft external ATU
is used or when no external matching unit is
present.  The TUNE button on the K2 keys
the transmitter at the requested TX power
set by the POWER control, e.g. 100 watts,
in the absence of a connected Elecraft
ATU.

To fool the K2 into using a lower TUNE
power setting than the POWER control
displays, one would need to reverse engineer
the AUXBUS protocol to make the K2 think
an Elecraft ATU is connected.  The K2's
MCU would have to communicate with the
spoofing unit in such a way as to make it appear
that the spoofing unit is an Elecraft ATU.
The AUXBUS protocol has not been made
publicly available to the best of my knowledge.

73,
Mike, K8CN