Just received from Twitter
KX3: Ultra-compact K3/KX1 hybrid, 160-6 m, 10/100 W, all-mode, 32-bit DSP/SDR, 1.5 lbs.
1.7? x 3.5? x 7.4?
internal battery pack & charger
internal wide-range ATU
new adjustable, attached keyer paddle
…and a K3-like front panel, including the same LCD.
RX-mode current drain ~150 mA. Very efficient on TX, with dual-output-impedance 5W/10W PA.
The optional 100W amp is in an external chassis. The internal amplifier is 10W with switchable impedance matching so it can also operate with maximum efficiency at 5W.
Totally different architecture than the K3, of course. (Wayne N6KR)
The MOSFET 10-W amp stage includes an output transformer with both 1:4 and 1:1 windings. When using low power, or when running from internal batteries, the 1:1 winding is used, which optimizes efficiency at about 5 W, greatly reducing transmit current drain. The 1:4 winding is used when running higher power (using an external supply).