ELECRAFT K3 User manual

ELECRAFTK3
HIGH-PERFORMANCE
160 –6 METER TRANSCEIVER
OWNER’SMANUAL
Revision D1, July 27, 2008
Copyright © 2008, Elecraft, Inc.
All Rights Reserved

2
Contents
A Noteto K3 Owners.......................................3
Key to Symbols and Text Styles.......................3
Quick-Start Guide.............................................4
Introduction.......................................................7
K3 Features.....................................................7
Specifications..................................................8
Customer Service and Support........................10
Front Panel......................................................11
ControlGroups..............................................11
Display.........................................................12
LEDs............................................................13
Front Panel Connectors..................................13
Primary Controls...........................................13
Multi-Function Controls.................................14
VFO Tuning Controls....................................14
Keypad.........................................................15
Memory Controls..........................................16
Message Record/Play Controls.......................16
RIT and XIT Controls....................................16
Rear Panel.......................................................17
Connector Groups..........................................17
KIO3 Module................................................18
Basic Operation..............................................21
Receiver Setup..............................................23
Reducing Interference and Noise....................25
Transmitter Setup..........................................26
Voice Modes (SSB, AM, FM)........................28
CW Mode.....................................................30
Data Modes...................................................31
Advanced OperatingFeatures.........................33
Text Decode And Display..............................33
CW-to-DATA...............................................34
Tuning Aids: CWT and SPOT........................34
Audio Effects (AFX)......................................35
Dual Passband CW Filtering...........................35
Receive Audio Equalization (EQ)...................35
Transmit Audio Equalization (EQ)..................35
SPLIT and Cross-Mode Operation..................36
Extended Single Sideband (ESSB)..................36
General-Coverage Receive.............................36
VFO B AlternateDisplays..............................36
Alarm and Auto Power-On.............................36
Using the Sub Receiver..................................37
Receive Antenna In/Out.................................38
Buffered I.F. Output...................................... 38
Using Transverters........................................ 38
Scanning...................................................... 39
Main and Sub Receiver Antenna Routing......40
Basic K3 (no KAT3 or KXV3) ...................... 40
K3 with KXV3 RF I/O Module...................... 40
K3 with KAT3 ATU..................................... 41
K3 with KAT3 and KXV3............................. 42
Remote Control of the K3..............................43
Options...........................................................44
Firmware Upgrades........................................44
Configuration.................................................45
Crystal Filter Setup....................................... 45
Option Module Enables................................. 46
Miscellaneous Setup...................................... 46
VFO A Knob Friction Adjustment................. 47
VFO B Knob Friction Adjustment.................. 47
Real Time Clock Battery Replacement........... 47
Calibration Procedures...................................48
Synthesizer................................................... 48
Wattmeter..................................................... 48
Transmitter Gain........................................... 48
ReferenceOscillator......................................49
Front Panel Temperature Sensor.................... 50
PATemperature Sensor................................. 50
S-Meter........................................................ 50
Menu Functions..............................................51
MAIN Menu................................................. 51
CONFIG Menu............................................. 52
Troubleshooting.............................................59
Parameter Initialization................................. 61
Module Troubleshooting............................... 62
Theory Of Operation......................................66
RF BOARD.................................................. 66
KANT3 and KAT3....................................... 68
KIO3............................................................ 68
Front Panel and DSP..................................... 68
KREF3......................................................... 69
KSYN3 ........................................................ 70
K3 Block Diagram........................................ 71
AppendixA: Crystal Filter Installation..........72
Index...............................................................76

3
A Note to K3 Owners
On behalf of our entire design team, we’d like to thank you for choosing the Elecraft K3 transceiver.
The K3—like its predecessor, the K2—reflects our desire to go beyond what other high-performance
transceivers have offered. It isn’t just a home-station rig; at about 8 to 9pounds, it can accompany you
wherever you go, whether it’s out to your back porch or halfway around the world. And it’s the only
rig in its class that you can build yourself. Above all, we want the K3 to be ready for any operating
situation you encounter, and be more enjoyable to use than any transceiver you’ve ever owned.
In addition to this manual, you’ll find much more information on the K3 on our web site, including
operatingtips, answers to frequently asked questions, and information on firmware upgrades.
73,
Wayne, N6KR
Eric, WA6HHQ
Key to Symbols and Text Styles
Important –read carefully
Operating tip
LSB
. .
LCD icon or characters
LED
Enter keypad function
XMIT
TUNE
Tap switch function (labeled on a switch)
Hold switch function (labeled below a switch;hold for 1/2 sec. to activate)
SQL
PWR
MON
Rotary control without integral switch
Tap switch function of rotary control (labeled above a knob)
Hold switch function of rotary control (labeled below a knob; hold for 1/2 sec.)
MAIN:VOX GN Typical MAIN menu entry
CONFIG:KAT3 Typical CONFIG menu entry

4
Quick-Start Guide
To get started using your K3 right away, please readthispage andthe two that follow, trying each of the
controls. The text uses braces to referto numbered elements in the front- and rear-panel illustrations below. For
example, {1}refers to 1, the mic jack. Later sectionsprovide greater detail on all aspectsof K3 operation.
The first thing you needto know about the K3 isthat most switches have two functions. Tap (press
briefly) to activatethe function labeled on a switch. Hold to activatethe function labeled below the switch. In
the text, tap functions are shown like this: MENU . An example of a hold function is CONFIG . Additional
typographical conventions are shown on the previous page.
Try tapping MENU {8}. This brings up the MAIN menu. Rotating VFO B {19} selects menu entries, while
rotating VFO A {22} changestheir parameters. Tap MENU againto exit the menu.

5
Connections Connect a power supplyto the DC input jack {26}(see Specifications, pg. 8).
On the K3/100, a circuit breaker is provided on the fan panel for the 100-W stage {30}
.
You can power an accessory device from the switched DC output jack {38}(0.5 A max).
Connect an antenna to ANT1 {29}. If you have an ATU installed (pg. 22), you can connect
a second antenna to ANT2 {28}. Ifthe KXV3 is installed, you can connect a separate RX
antenna to RX ANT IN {34}. The AUX RF connector {27} is optional; see pg. 17.
The Basics Press POWER {5}to turn on the K3. If there are any error indications, refer to pg. 63.
TAP and HOLD Functions: Tapping briefly activatesthe function labeled on
a switch.
Holding for about 1/2 second activatesthe function labeled below a switch.
Tap either end of BAND {7}to select a band, andtap MODE {6}to select the mode. Set
the AF gain using AF {2}. Set RF to max. SUB controls are discussed on pg. 37.
The large knob {22} controls VFO A (upper display, {10}). The medium knob {19}
controls VFO B (lower display, {11}). VFO A is main RX/TX except in SPLIT (pg. 36).
CMP /PWR is one of four multifunction controls {24}. Each hastwo primary
functions, indicated by green LEDs. The knob has a built-in switch; tap it to select either
CMP (compression level) or PWR (power output). Holdthe knob in to access its
secondary function, MONitor level. Tap again to restore the primary function.
Filter
Controls
Rotate the SHIFT/ LOCUT and HICUT/ WIDTH controls {23}to adjust the filter
passband. Crystal filters FL1-FL5 are automatically selected as you change the
bandwidth. Tap either knobto alternate between shift/width and hicut/locut.
Hold SHIFT/ LOCUT to NORM
alize the bandwidth (e.g., 400 Hz CW, 2.8 kHz SSB).
Hold HICUT/ WIDTH to alternate between two filter setups, Iand II (per-mode).
Tap XFIL {13} to select crystalfilters manually; this also removes any passband shift.
Voice Modes
{1}
Hold METER {8}to see CMP /ALC levels. Whiletalking, set MIC {25} for 4-7 bars
of ALC, and CMP for the desired compression. Then return to SWR /PWR (pg. 28).
Optional: Hold TEST {6} for TX TESTmode; allows off-air TX adjustments (pg. 13).
Hold CMP / PWR {24}to set speech MONitor level;tap to returnto CMP /PWR.
Hold VOX {7}to select PTT or VOX. Hold SPEED/ MIC to set VOX DELAY.
Details: VOX, pg. 29; TX EQ, pg. 35; MIC SEL, pg. 51; SSB/AM/FM, pg. 28.
CWMode
{36}
SPEED {25} setsthe CW keyer speed. Holdthisknobto set semi-break-in DELAY
.
Hold QSK {7}to select full break-in (QSK icon on) or semi-break-in. (Pg. 30.)
Hold PITCH {18}to set sidetone pitch. Hold CMP / PWR to set sidetone MON level.
Tap CWT {18} for tuning aid {9} (pg. 34). With CWT on, SPOT auto-tunes(pg. 30).
To select CW text decode/display mode, hold TEXT DEC {18}; rotate VFO B (pg. 30).
CW keying is convertedto DATA in FSK D and PSK D modes (below and pg. 34).
Hold DUAL PB {13}to turn CW dual-passband filter (pg. 30).
Data Modes
{31}
Tap MODE {6} untilyou see the DATA icon turn on (see Data Modes, pg. 31).
Hold DATA MD {18}. Use VFO B to select from: DATA A (PSK31 & other
soundcard-based modes), AFSK A (soundcard-based RTTY), FSK D (RTTY via data
input or keyer), or PSK D (PSK via data input or keyer). VFO A selects data baud rate
for internal encoder/decoder, if applicable. DUAL PB turnson RTTY filter (DTF, pg. 32).
Hold PITCH {18}to select mark tone and shift (for encoder/decoder and RTTYfilter).
Hold TEXT DEC {18}to set up text decode. CWT shows tuning aid (pg. 34).

6
VFOs
and RIT/XIT
RATE {21} selects10 or 50 Hz VFO/RIT tuning. See VFO menu entries, pg. 52.
FINE {21} selects 1-Hz steps. COARSE selects large steps (MAIN menu, VFO CRS).
Tap FREQ ENT {21}to enter frequency in MHz using numeric keypad & decimal point.
Tap return ( ) to complete the entry, or tap FREQ ENT again to cancel. (Pg. 15.)
Hold SCAN to start/stop scanning. SCAN must be preceded by a memory recall (pg. 39).
The RIT and XIT offset knob {17}has LEDsthat show -/0/+ offset (pg.16). Tap CLR
{16}to zerothe offset. Hold CLR for >2 sec. to add the offset to VFO A, then zero it.
Transmit,
ATU, and
Antenna
Controls
The TX LED {4} indicatesthat the K3 is intransmit mode. The ∆fLED turns on if the
RX andTX frequencies are unequal (SPLIT,RIT/XIT, cross-mode, etc.). (Pg. 13.)
XMIT {8} is equivalent to PTT {35}.TUNE puts out full CW power in any mode.
ATU TUNE {8} initiates antenna matching (pg. 22). ATU enables or bypasss the ATU.
ANT selects ANT1 or ANT2.RX ANT selects main or RX antenna (KXV3).
NB, NR,
and Notch Tap NB {12}to enable DSP and I.F. noise blanking. Hold LEVEL to set DSP NB level
(VFO A) and I.F. NB level (VFO B). Fully CCW is OFF in both cases. (Pg. 25.)
Tap NR {12}to turn on noise reduction. Hold ADJ to tailor noise reduction for the
present band conditions (pg. 25).
Tap NTCH {12} once to select auto-notch (NTCH icon), and a secondtime to select
manual notch (adds icon). Hold MAN to adjust manualnotch frequency. (Pg. 25.)
SPLIT,
BSET,
and SUB
Hold SPLIT {13}to enter split mode (RXon VFO A, TX on VFO B). If VFOs A and B
are on different frequencies in SPLIT mode, the Delta-F LED (∆f) willturn on (pg. 13).
Hold BSET {13}to adjust VFO B / sub RX settings independently of VFO A (pg. 37).
Tap SUB {20} to turn on the sub receiver (pg. 37). VFO B controls its frequency.
Hold SUB {20} to link the two VFOs (VFO A is then the master). This allows diversity
receive with main and sub if two different antennas are used (pg. 37).
Memories,
Messages, and
DVR
To store a frequency memory, tap V M {14}, then:tap M1 -M4 {15} to save a per-band
quick memory; or tap 0-9to save a general-purpose quick memory; or rotate VFO A to
select from memories 0-99, thentap V M again to save. Tap M V to recall. (Pg. 16.)
REC and M1 -M4 {15} are also used to record & play voice/CW/DATA messages. The
KDVR3 option is required for voice messages and AF REC /AF PLAY (pg. 29).
Menus MENU &CONFIG {8} access the MAIN and CONFIG menus. VFO B selects entries;
VFO A changes parameters. In general, CONFIG menu entries are used less often.
Tapping DISP {8} within menus shows information about each entry on VFO B (pg51).
Up to 10 menu entries can be assignedto programmable function switches. PF1 and PF2
{16} are dedicated programmable functions. Any of M1 -M4 {15} can be used as Tap
and/or Hold programmable functions if they’re not being used for message play (pg 51).
Other
Features
RX andTX EQ (MAIN menu) provide 8 bands of receive/transmit equalization (pg. 35).
Tap AFX {18}to enable the selected audio effect (see CONFIG:AFX MD, pg. 51).
Tap DISP {8} and use VFO B to show time, supply voltage, etc. on VFO B (pg. 36).
The ALARM function (MAIN:ALARM menu entry) can be used to remind you about a
contest, net, or QSO schedule, and can eventurn the K3 on at alarm time (pg. 36).
The KIO3 module provides a rich set of AF {33} and digital {32} I/O (pg. 17).

7
Introduction
This comprehensive manual covers all the features
and capabilities ofthe Elecraft K3transceiver. We
recommend that you begin with the Quick-Start
Guide (pg. 4).The Front Panel (pg. 11) and Rear
Panel (pg. 17) sections are for general reference,
while Basic Operation (pg. 21) and Advanced
Operation (pg. 33) fill in the details.
Your K3, including any installed crystal filters
and option modules, should already be configured.
Anytime you add new filtersor options, refer to
Configuration (pg. 45).
K3 Features
The K3 offers a number of advanced featuresthat
simplify operation and enhance versatility. These
are listed below. Referto the indicatedpages for
further details.
Receiver
Up to five crystalroofing filters with
bandwidths as narrow as 200 Hz (pg. 23)
High-performance, fully independent sub
receiver, also with up to five crystalfilters,
allows true diversity receive withtwo
antennas (pg. 37)
Variable-bandwidth crystal filtersthat track
DSP filter settings
Narrow ham-band front-endfilters, plus
wider band-pass filters for general-coverage
receive (pg. 44)
DSP
32-bit I.F. DSP for advanced signal
processing, including full stereo and other
binaural effects (pg. 35)
Passband tuning and programmable
DSP/crystal filter presets(pg. 14)
8-bandtransmit and receive EQ (graphic
equalization) (pg. 35)
Dual-passband effects for use in
contest/pileup conditions (pg. 30)
Versatile digital voice recorder (DVR) for
incoming/outgoing audio streams (pg. 29)
CW and Digital Modes
Built-in digital-mode demodulation with
text displayed on the K3’s LCD (CW,
RTTY, PSK31) (pg. 33)
Internal CW-to-RTTY or CW-to-PSK31
text decode/encode for casual digital-mode
QSOs without a computer (pg. 34)
CW text can be decoded and displayed as
you send –great for improving CW skills
(pg. 33)
Automatic CW/data signal spotting and
manual fine-tuning display (pg. 30)
User Interface
Dual VFOs with independent modes,
bands, and filter settings (pg. 14)
100 memories with alphanumeric labels,
plus 4 quick-memoriesper band (pg. 16)
Dedicated message play controls for use in
CW, data, and voice modes (pg. 30)
Real-time clock/calendar with
programmable alarm times and automatic
power-on (pg. 36)
Utility displays show voltage, current drain,
RIT/XIT offset, front panel temperature,
PA heatsink temperature, etc. (pg. 36)
Instructionsfor menu entriesavailable with
one switch tap
Connectivity
Enhanced, high-speed remote control
interface with many new commands and
direct DSP access
Firmware upgradeable via the Internet (pg.
44)
Isolated PC audio input and stereo outputs
(pg. 17)
Front and rear mic andheadphone jacks
Full stereo audio drivestwo speakers
Optional RX antenna in/out,transverter
in/out, and bufferedIF outputs (KXV3)

8
Specifications
Some specificationsapply only if the corresponding option modules are installed (see Options, pg. 44).
GENERAL
Frequency Range Main and Sub Receivers, 500 kHz - 30 MHz and 48-54 MHz. Transmitter: Amateur
bands between 1.8 and 54 MHz; transmit limits vary by country.
Tuning Step Sizes 1, 10, 20, and 50 Hz; user-configurable coarse tuning steps (per-mode). Direct keypad
frequency entry in either MHz or kHz
Memories 100 general purpose, plus 4 “quick memories”per band
Frequency Stability +/- 5 ppm (0-50 C)TCXO standard; +/- 1 ppm TCXO optional
Antenna Jacks 50 ohms nominal. One SO-239 supplied (2nd SO-239 jack supplied with KAT3 ATU).
BNC jacks for RX antenna in/out and transverter in/out (KXV3 Option).
Modes USB, LSB, AM, FM, CW, and DATA. In DATA mode: FSK D(Direct), AFSK A
(Audio), PSK D (Direct) and DATA A (Audio; PSK, etc.). Built in PSK, RTTY, and
CW text decode/display.
VFOs Dual VFOs (A and B) with separate weighted tuning knobs
Remote Control Port EIA-232 standard DE-9F; USB adapter option. Full control ofall radio functions
Audio I/O Line-level isolated TX/RX audio interface (stereo outputs); front (1/4”) and rear (1/8”)
stereo headphone jacks; stereo speaker jack
Low Level Transverter
Interface 0 dBm typ.; BNC connectors (KXV3 Option)
Buffered IF output BNC connector (KXV3 Option); see pg. 38 for interface recommendations
Other I/O Key/Keyer/Computer, Paddle, PTT In, and KEY Out. Band information output via
binary interface and AUXBUS on ACC connector.
Real-Time Clock/Calendar Accuracy: Approx. +/- 20 ppm (+/- 2 seconds/day). U.S. and E.U. date formats.
Battery: 3 V coin cell (see pg. 47 for replacement instructions).
Supply Voltage
/Current 13.8 V nominal (11 V min, 15 V max). 17-22 A typical in TX for K3/100, 3-4 A typical in TX for K3/10. 0.9A typical RX(less sub receiver).
Recommended supply: 13.8VDC @ 25A, continuous duty for K3/100; 13.8VDC @
6A for K3/10. For best results, use thesupplied 5 foot (1.53 m) power cable.
Accessory DC output Switched, 0.5 A max; 13 V no-load, 12 V max load (@ Vsupply = 13.8 V)
Weight (K3/100) Approx. 8.5 lbs. (3.8 kg). With KRX3 sub receiver option, 9.5 lbs. (4.3 kg).
Size Enclosure only, 4.0 x 10.7 x 10.0 in., HWD (10.2 x 27.2 x 25.4 cm); with projections,
4.4 x 11.1 x 11.8 in. (11.2 x 28.2 x 30.0 cm)

9
RECEIVER (Main and Sub)*
Sensitivity (MDS) -136 dBm (typ.), preamp on, 500 Hz b/w. Reduced sensitivity near 8.2 MHz (first
I.F.). 6 m MDS with PR6 option: -143 to -144 dBm (typ.).
KBPF3 option required for full general-coverage receive, including broadcast band
(0.5 to 1.7 MHz). Note: Sensitivity gradually decreases below 1.8 MHz due to high-
pass response ofT-R switch. This protects thePIN diodes.
IMD3 Dynamic Range > 100 dB typical at 5, 10, and 20 kHz spacing.
Blocking Dynamic Range 140 dB typical at 5, 10, and 20 kHz spacing
Image and I.F. Rejection > 70 dB
Audio Output 2.5 W per channel into 4 ohms; typ. 10% THD @ 1 kHz, 2 W
S-Meter Nom. S9 = 50 µV, preamp on; user-adjustable
Noise Blanker Adjustable, multi-threshold/multi-width hardware blanker plus DSP blanker
Receive AF graphic EQ +/- 16 dB/octave, 8 bands
Filter Controls IF Shift/Width & Lo/High Cut with automatic crystal filter selection
*Dynamic range measurements based on 400-Hz, 8-pole filter. Other available filters have very similar performance; see
www.elecraft.com for full list. Receive specifications are guaranteed only within ham bands.
TRANSMITTER *
Output Power K3/100: 0.1 W –100 W typ. (reduced power in AM mode).
K3/10 (or K3/100 with PA bypassed): 0.1 W –12 W, HF-10 m; 8W max on 6 m.
XVTR OUT (KXV3 option): 0.1 to 1.5 mW (-10 to +1.8 dBm).
Duty Cycle CW and SSB modes, 100% 10-min. 100W key-down at 25 C ambient
True RF Speech Processor Adjustable compression
Transmit AF graphicEQ +/- 16 dB/octave, 8 bands
SSB TX Bandwidth 4 kHz max (> 2.8 kHz requires 6 kHz AM filter)
SSB TX Monitor Post-DSP filtering/processing
VOX DSP-controlled, adjustable threshold, delay, and anti-VOX
Full and Semi CWBreak-In Adjustable delay; diode T/R Switching
SSB Carrier Suppression > 50 dB
Harmonic and Spurious
Outputs > 50 dB below carrier @ 100W (> 60 dB on 6 meters)
CW Offset/Sidetone 300-800 Hz, adjustable (filter center frequency tracks sidetone pitch)
Mic Front panel 8 pin mic connector; rear panel 3.5 mm mic connector. Switchable DC
bias voltage available for electret mics (see MAIN:MIC SEL menu entry)
* Transmit specifications are guaranteedonly within ham bands.

10
Customer Service and Support
Technical Assistance
You can send e-mailto [e-mail] and we will respond quickly –typically the same day
Mondaythrough Friday. If youneed replacement parts, send an e-mailto [e-mail]. Telephone
assistance is available from 9 A.M. to 5 P.M.Pacific time (weekdaysonly) at 831-662-8345. Please use e-mail
ratherthan calling when possible since this gives us a written record of the details of your problem and allows us
to handle a larger number of requests each day.
Repair / Alignment Service
If necessary, you may return your Elecraft product to us for repair or alignment. (Note: We offer unlimited email
and phone support, so pleasetry that route first as we can usually help you findthe problem quickly.)
IMPORTANT: You must contact Elecraft before mailing your productto obtain authorization forthe
return, what address to ship it to and current information on repair fees and turn aroundtimes. (Frequently we
can determine the cause of your problem and save you the trouble of shipping it back to us.) Our repair location
is different from our factory location in Aptos. We will give youthe address to ship your kit to at the time of
repair authorization. Packages shipped to Aptos withoutauthorization will incuran additional shipping charge
for reshipment from Aptos to our repair depot.
Elecraft 1-Year Limited Warranty
This warranty is effective as of the date of first consumer purchase. It covers both our kits and fully
assembled products. For kits, before requesting warranty service, you should fully complete the assembly,
carefully following all instructions in the manual.
What is covered: During the first year after date of purchase (or if shipped from factory, date product is
shipped to customer), Elecraft will replace defective or missing parts free of charge (post-paid). We will
also correct any malfunction to kits or assembled units caused by defective parts and materials. Purchaser
pays inbound shipping to us for warranty repair, we pay shipping to return the repaired equipment to you
by UPSground service or equivalent to the continental USA and Canada. Alaska, Hawaii and outside U.S.
and Canada actual return shipping cost paid by owner.
What is not covered: This warranty does not cover correction of kit assembly errors. It also does not
cover misalignment; repair of damage caused by misuse, negligence, or builder modifications; or any
performance malfunctions involving non-Elecraft accessory equipment. The use of acid-core solder, water-
soluble flux solder, or any corrosive or conductive flux or solvent will void this warranty in its entirety.
Also not covered is reimbursement for loss of use, inconvenience, customer assembly or alignment time,
or cost of unauthorized service.
Limitation of incidental or consequential damages: This warranty does not extend to non-Elecraft
equipment or components used in conjunction with our products. Any such repair or replacement is the
responsibility of the customer. Elecraft will not be liable for any special, indirect, incidental or
consequentialdamages, including but not limited to any loss ofbusinessor profits.