[Elecraft] K3 AM mode

[Mark Bayern]

It appears the firmware now does AM. From the latest firmware release notes:

----

Current K3 Firmware Revisions

Last Release: Dec 14, 2007

MCU:  V 1.49            DSP:  V 1.46

    *

      Noise Reduction significantly improved. Also, NR can be used
with narrow filters in CW mode.
    *

      AM mode added. (6 kHz Filter required.)

      NOTE: Power control temporarily works as follows: when you set
power to 100 W in AM mode, it means 100 W *peak power*, and 25 W
*carrier power*.  Also, the bar graph shows peak power in AM mode.
This will be corrected later so the display and bar graph both show
carrier power.
    *

      Manual notch frequency defaults to 2 kHz (originally 200 Hz).

See 'Release Notes'  in the K3 Update Utility for a complete revision history.