Elecraft KX3 Owner's Manual - Manual (Page 5)

5
Avoid using bulky connectors or adapters
that could put excessive stress on side-panel
jacks. Lightweight cables, preferably with right-
angle plugs, are strongly recommended.
Headphones and Speakers
The 3.5-mm PHONES jack, on the left side panel,
accommodates mono or stereo headphones. You
can also plug in one or two amplified (or powered)
external speakers here. Mono or stereo plugs can be
used. Stereo allows the use of audio effects,
providing an enhanced listening experience (pg.
29).
The KX3 includes a small built-in speaker for use
in quiet operating environments. Plugging in
headphones disables the speaker and its amplifier.
(This is an easy way to extend battery life.)
Mobile installations: The interior of most vehicles
is too noisy for use with the KX3’s built-in speaker.
One or two amplified mobile speakers can be
plugged into the PHONES jack, or you can connect
this jack to your car stereo’s AUX input. Another
alternative is to use a device that retransmits the
KX3’s audio output in the FM broadcast band.
Microphone
The MIC jack is compatible with the Elecraft MH3
hand mic, which provides PTT as well as VFO
UP/DN buttons. For the MH3, set the MIC BIAS
menu entry to
O N , and MIC BTN to P TT U P .D N .
MH3 Mic Pinout
Sleeve: Shield
Ring2: Logic ground
Ring1: PTT/UP/DN
Tip: Mic audio
Using other microphones and headsets: The KX3
is compatible with many headset-mics that have
separate 3.5-mm plugs for mic audio and receive
audio. You can also use some “mini” mics intended
to plug directly into a laptop computer. Refer to the
MIC BIAS and MIC BTN menu entries to set up
the KX3 for use with your mic or headset.
Computer/Control Port (ACC1)
The 3.5-mm stereo ACC1 jack allows firmware
updates, configuration, and remote control of the
KX3 via a computer. The jack can be connected to
a computer’s USB port via the Elecraft model
KXUSB cable, or to an RS232 port via the model
KXSER cable. (The jack’s tip connection is RX
data from the computer. Ring is TX data to the PC.)
Elecraft provides two KX3 configuration programs:
KX3 Utility is required for KX3 configuration and
firmware updates (pg. 25). It also provides a
CW/data terminal function.
Our K3 Memory PC application can be used with
the KX3 to set up frequency memories more easily
than with the radio’s memory-store function.
Many logging, contesting, and control programs are
available from third parties. If the KX3 is not
specifically supported by a given program, try
selecting Elecraft K3 or K2.
Keyline Out and GPIO (ACC2)
The 2.5-mm stereo ACC2 jack provides a keyline
output (ring contact) and a general-purpose 3-volt
logic signal (tip contact).
The keyline output goes low during transmit, and
can be used for transmit/receive switching of linear
amplifiers and transverters. For keyline voltage and
current limits, see Specifications.
The general-purpose signal, GPIO, can be set up for
various equipment control functions. For example,
it can send band-change information to Elecraft
XV-series transverters. See the ACC2 IO menu
entry for a full list of uses for this signal, as well as
hardware interface requirements.
Quadrature Outputs (RX I/Q)
The 2.5-mm RX I/Q jack provides quadrature
outputs from the receive mixer (I=in-phase;
Q=quadrature, or 90 degrees out of phase). These
outputs can be used with the Elecraft PX3
Panadapter, as well as with computer-based
software-defined radio (SDR) programs, to extend
the capabilities of the KX3. See SDR Applications
(pg. 26).