Elecraft • www.elecraft.com • 831-763-4211
Elecraft KXAT2 Automatic Antenna Tuner
Installation Instructions
Revision B, June 26, 2017
E740294
Copyright © 2017, Elecraft, Inc. All Rights Reserved
Introduction
The KXAT2 internal automatic antenna tuner converts a wide range of impedances presented by antennas to a
value close to 50 ohms, non reactive (i.e. low SWR) for the KXAT2 itself. This allows the transmitter in the KX2
to deliver full RF power in transmit and can also improve sensitivity in receive.
Even many non-resonant “random” wire antennas can be used effectively with the KXAT2 installed.
When commanded to tune, the KXAT2 searches for the best match (lowest SWR to the transmitter). Once a
tuning solution has been located, the solution is stored so that retuning requires less than 1 second. One tuning
solution is stored for each band.
The KXAT2 is a single pc board (see below) that fits inside the KX2 enclosure.
If you would like Elecraft to install this modification for you, contact Elecraft technical support at
or call 831-763-4211.
IMPORTANT!
A modification was released shortly after KX2 production began that further reduces
harmonic energy in the transmitter output. If you have an early KX2 that has not been
modified, it is most conveniently done while installing the KXAT2. The necessary parts are
included with this kit. No soldering or special tools are required. Simply follow the steps
that refer to installing the modification where you encounter them in the following
procedure.
ESD-Sensitive! A grounded wrist strap and ESD dissipating mat are recommended
whenever you work inside your K3. Optionally, touch a bare metal ground frequently while
working.
KXAT2 Antenna Tuner Option Circuit Board
