ELECRAFT K4 Reference manual

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Introduction to the Elecraft K4
(Preliminary)!
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Rev.!A-7,!Sept.!23,!2020!
Copyright!2020,!Elecraft,!Inc.!
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TABLE!OF!CONTENTS!
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OVERVIEW!...................................................!3!
INSTALLATION!..............................................!4!
REAR!PANEL!CONNECTORS!...........................!5!
POWER!ON/OFF!...........................................!6!
DISPLAY!........................................................!7!
BUILT-IN!OPERATING!MANUAL!.....................!8!
VFO!A!CONTROLS!..........................................!9!
BAND!SELECTION!........................................!10!
MODE!SELECTION!.......................................!11!
VFO!B!CONTROLS!........................................!12!
MULTIFUNCTION!CONTROLS!......................!13!
RECEIVER!CONTROLS!AND!ICONS!................!14!
MAIN!AND!SUB!RECEIVER!CONFIGURATION!15!
PARAMETER!ADJUSTMENTS!.......................!16!
RX!AND!TX!EQ!.............................................!17!
TX!METERING!.............................................!18!
PANADAPTER!SETTINGS!..............................!19!
DISPLAY!AND!PANADAPTER!SELECTION!......!20!
DUAL!PANADAPTERS!..................................!21!
MINI-PAN!TUNING!AID!...............................!22!
TEXT!DECODE/ENCODE!...............................!23!
MENU!........................................................!25!
ANTENNA!SELECTION!.................................!26!
ANTENNA!ICONS!........................................!27!
RX!ANTENNA!CONTROLS!.............................!28!
RX!ANTENNA!SWITCH!CONFIGURATION!......!29!
STATUS!DISPLAY!SETTINGS!.........................!30!
ON-SCREEN!KEYBOARD!...............................!31!
SPECIAL!FUNCTIONS!(FN)!.............................!32!
DX!PREFIX!LIST!............................................!33!
SPOT!AND!AUTO-SPOT!................................!34!
FREQUENCY!MEMORY!STORE!/!RECALL!.......!35!
INTERNAL!CW!KEYER!CONFIGURATION!.......!36!
MICROPHONE!CONFIGURATION!.................!37!
LINE!IN!CONFIGURATION!............................!38!
LINE!OUT!CONFIGURATION!.........................!39!
SPECIFICATIONS!.........................................!40!
MENU!LISTING!............................................!41!
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OVERVIEW!
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This!short-form!manual!is!intended!as!an!introduction!to!the!K4,!providing!the!essential!information!you’ll!need!to!get!on!the!air.!Refer!to!the!Elecraft)K4)Owner’s)
Manual!!for!additional!details!on!all!topics.!!NOTE:!All!text!and!illustrations!are!preliminary!and!subject!to!change.!
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The!Elecraft!K4!is!a!high-performance,!direct-sampling!software-defined!radio!(SDR).!It!covers!the!160!~!6!m!bands,!with!continuous!receive!from!100!kHz!~!54!MHz.!
10!W!and!100!W!models!are!available.!It!can!be!used!with!internal!or!external!transverters!to!cover!bands!above!6!meters.!!
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Among!the!K4's!notable!features:!!Large!color!touch!screen,!as!well!as!support!for!an!external!HDMI!monitor;!extensive,!easy!to!use!controls;!rich!analog!and!digital!
connectivity;!dual!receive!(all!models);!built-in!data!modes,!and!wide-range!automatic!antenna!tuner.!The!K4's!compact!size!and!weight,!combined!with!11-15!VDC!
operation!and!low!current!drain,!make!it!suitable!for!field,!travel,!or!home!station!use.!
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Since!the!K4!is!an!SDR,!Elecraft!can!provide!updates!to!its!signal!processing!algorithms!with!software!changes!rather!than!by!adding!new!hardware.!This!ensures!that!
the!K4!can!take!advantage!of!new!modes,!bands,!or!other!features!in!the!future.!Since!it!uses!direct!sampling,!signals!are!digitized!right!at!the!receiver!inputs,!and!
the!transmitter's!amplifier!chain!is!also!driven!by!a!digitized!signal.!Older!SDR!architectures!digitized!signals!at!a!low!intermediate!frequency!(IF),!resulting!in!poor!
suppressions!of!down-conversion!or!up-conversion!images.!
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There!are!three!models:!the!basic!K4,!with!one!set!of!receive!filters!and!one!analog-to-digital!converter!(ADC);!the!K4D,!which!adds!a!second!set!of!receive!filters!
and!a!second!ADC;!and!the!K4HD,!which!adds!a!superheterodyne!front!end!that!can!be!enabled!when!needed!to!provide!even!greater!dynamic!range.!The!superhet!
module!uses!high-performance,!narrow-band!crystal!filters.!All!K4!models!provide!simultaneous!dual!receive!on!the!same!or!different!bands/modes,!though!the!
additional!receiver!module!in!the!K4D!and!K4HD!(KRX4)!improves!signal!handling!during!dual-receive!operation!on!different!bands.!The!second!receiver!also!permits!
diversity!reception,!i.e.,!the!use!of!different!antennas!for!the!two!receivers!to!counteract!fading!(QSB).!
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A!basic!K4!can!be!upgraded!to!a!K4D!by!installing!the!KRX4!option.!Similarly,!a!K4D!can!be!upgraded!to!a!K4HD!by!installing!a!KHDR4!module.!Other!internal!options!
and!external!accessories!work!with!all!models,!including!a!wide-range!ATU!(KAT4),!MH4!microphone,!SP4!external!speaker!(1!or!2).!!
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INSTALLATION!
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CAUTION:!!Ground!your!K4!properly!before!operation.!For!suggestions,!see!www.arrl.org/grounding.!!
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ESD!and!Lightning!Protection:!!Even!though!the!the!K4!has!extensive!internal!protective!circuitry,!external!protection!against!lightning!strikes!is!strongly!
recommended,!especially!in!lightning-prone!areas.!During!storms!and!when!the!station!is!not!in!use!for!an!extended!period,!disconnect!ALL!equipment!from!the!
radio,!including!antennas,!the!power!supply,!routers!or!hubs,!and!computers.!Ethernet,!USB,!and!RS232!cables!are!a!frequent!source!of!damaging!surge!voltages.!
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Orientation!and!Air!Flow:!!Provide!at!least!1"!of!free!space!above!and!behind!the!K4.!Ventilation!holes!on!the!bottom!and!left!sides!must!also!not!be!blocked.!
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Using!the!Tilt!Stand:!!If!the!K4!is!placed!on!a!desk!or!table,!deployment!of!the!tilt!stand!is!recommended!to!facilitate!interaction!with!the!touch!screen.!This!will!also!
improve!the!display!viewing!angle.!
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Interfacing!to!Station!Equipment:!!The!illustration!on!the!next!page!shows!the!locations!of!all!rear-panel!connectors.!At!minimum!you'll!need!to!connect!a!power!
supply,!antenna,!and!station!ground.!(See!power!supply!and!antenna!recommendations!below.)!An!Ethernet!connection!is!required!for!software!upgrades.!The!K4)
Owner’s)Manual!provides!full!instructions!for!interfacing!to!computers,!amplifiers,!and!other!equipment.!!
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Power!Supply:!!A!power!supply!voltage!of!13.8!to!14.2!V!is!preferred.!Minimum!supply!voltage!is!11.0!V,!while!current!required!is!either!6!A!max!(K4/10)!or!25!A!
max!(K4/100).!The!K4!will!automatically!reduce!power!output!if!the!supply!voltage!is!inadequate!to!maintain!good!IMD!performance.!Use!the!shortest!practical!
length!of!power!cable,!with!heavy!wire!gauge!to!minimize!voltage!drop.!The!supplied!power!cable!includes!fuses!in!both!legs.!
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Antennas:!!If!your!K4!includes!the!KAT4!ATU!option,!you!can!match!a!wide!variety!of!loads!to!the!transceiver!by!tapping!the!ATU!TUNE!switch.!If!not,!you’ll!need!to!
use!matched!antennas!(nominally!50!ohms)!or!an!external!antenna!matching!device.! !

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REAR!PANEL!CONNECTORS!
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ANT1/2/3!! HF-6M!(used!with!KAT4!ATU)!!!ETHERNET!Connect!to!router!or!modem! ! PHONES!Rear!headphones!(in!addition!to!front)!
ANT4!!! Supplied!with!internal!XVTR!option! ! USB!A!(x2)!Type!A!(keyboard,!mouse,!K-Pod)! ! MIC! ! Rear!mic!(in!addition!to!front)!
12!VDC!In!!!!!11-16!V;!6!A!(10W)!/!25!A!(100!W)!!!USB!B!(PC)!Type!B!(for!ctrl/dig.!AF/PTT/KEY/FSK)! RS232!! True!RS232,!for!remote!ctrl,!KEY,!PTT!
12!VDC!Out!! Switched!accessory!supply!!!!HDMI! ! External!HDMI!monitor!!!PTT!IN!! Push-to-talk!line!(foot!switch,!etc.)!
TX!SMPL!In!For!use!with!compatible!amplifiers! ! REF!IN!! 10!MHz!external!reference!input! ! KEY!OUT!For!keying!external!amps,!etc.!
XVTR!IF!XVTR!I/O;!XVTR!IF!IN!doubles!as!RX!ANT!2!LINE!IN/OUT!600!ohms!(nominal),!analog!audio!! PADDLE/KEY!For!CW!paddle!/!hand!key!or!keyer!
RX!ANT!RX!ANT!IN!1,!and!RX!ANT!OUT!(for!filter)!! SPKRS!! 1!or!2!ext.!speakers!(e.g.,!SP4)! ! ACC! ! Accessory!signals!(see!Owner’s!Manual)!!

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POWER!ON/OFF!
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Note:!!In!this!document,!“switch”!refers!to!a!physical!switch,!while!“button”!refers!to!a!labeled!touch!control!on!the!LCD.!Yellow!arrows!are!used!to!indicate!controls!
being!described,!such!as!POWER!switch,!below.!!
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• Tap!the!POWER!switch!to!turn!the!K4!on.!The!logo!screen!will!appear!while!module!self-tests!are!performed.!Tapping!again!turns!power!off.!
• Hold!POWER!for!~2!seconds,!rather!than!tap,!to!enter!standby!mode!(at!any!time)!.!When!the!K4!is!in!standby!mode,!powering!up!is!much!faster,!at!the!expense!
of!non-zero!current!drain.!
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DISPLAY!
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• The!K4!has!a!full!color,!7”!LCD!screen.!Capacitive!touch!capability!allows!convenient,!intuitive!access!to!on-screen!controls.!A!mouse!can!also!be!used.!
• Each!VFO!has!a!large!numeric!display,!mode!indicator,!S-meter,!filter!passband!graphic,!and!full!set!of!receive!icons.!!
• The!main!receiver!is!always!associated!with!the!frequency!of!VFO!A.!When!the!sub!receiver!is!turned!on,!it!is!always!associated!with!VFO!B.!!
• The!RIT/XIT!offset!box!(in!white)!and!transmit!icons!(in!orange)!are!located!between!the!two!VFOs.!!
• Transmit!icons!include!SPLIT!on/off,!VOX,!transmit!antenna!name/number!(in!this!case,!“2:YAGI”),!ATU!in-line,!and!QSK.!
• The!remainder!of!the!display!is!used!for!the!panadapter,!multifunction!control!buttons!(at!left),!and!7!primary!function!buttons!(lower!edge).!
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BUILT-IN!OPERATING!MANUAL!
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• Tap!the!“?”!button!on!the!K4!front!panel!(identified!by!a!yellow!arrow,!below)!to!bring!up!the!built-in!operating!manual.!!
• To!see!information!on!the!controls!most!recently!used,!tap!the!LAST!CTRL!button!one!or!more!times.!!
• Use!the!VFO!A!knob!to!scroll!through!text.!Navigate!using!underlined!links!and!the!forward/back!arrow!buttons.!!
• Tap!the!table!of!contents!or!magnifying!glass!buttons!to!search!by!topic.!!
• A!button!is!provided!to!select!either!the!small!manual!format!(shown!here)!or!a!larger!format—using!the!entire!screen—to!reduce!the!need!for!scrolling.!
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VFO!A!CONTROLS!
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The!VFO!A!knob!controls!the!frequency!of!the!main!receiver.!It!is!also!used!to!adjust!parameters,!scroll!through!menu!entries,!etc.!Switches!near!the!VFO!A!knob!
control!related!functions:!
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• Tap!FREQ!ENT!to!directly!enter!an!operating!frequency.!Hold!SCAN!to!scan!between!VFO!A!and!VFO!B!of!the!last-recalled!frequency!memory.!
• Tap!RATE!to!select!1!or!10!Hz!tuning.!Hold!KHZ!to!select!a!per-mode!coarse!tuning!rate.!
• Tap!SUB!to!turn!on!the!sub!receiver.!Hold!this!switch!to!enter!DIVERSITY!mode.!LEDs!above!the!VFO!A!knob!show!the!status!of!these!settings.!
• To!lock!the!VFO!A!knob,!tap!the!LOCK!A!button.!A!hold!of!this!switch!locks!VFO!B.!!
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BAND!SELECTION!
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• Tap!the!BAND!button!to!change!bands!(see!arrow).!BAND!is!one!of!the!seven!primary!function!buttons.!
• A!band!button!can!be!tapped!multiple!times!to!rotate!through!recently!used!frequencies!and!modes!(also!known!as!band-stacking).!
• The!GEN!CVG!(general!coverage)!button!saves!several!recently!used!VFO!frequencies/modes;!it!is!not!limited!to!ham!bands.!!!
• MEM!nnn!saves!a!few!of!the!most!recently!recalled!frequency!memories!(via!the!RCL!switch).!!
• XVTR!n!is!used!to!access!transverter!bands.!!
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