Elecraft K4 Transceiver

A direct-sampling SDR you’ll love to use

Our new K4 harnesses the latest in signal processing while retaining the best aspects of the K3S and P3. The resulting user interface makes the technology transparent, allowing you to focus on working the world.

160-6 meter, all-mode coverage & dual RX

The K4 includes dual receive over 100 kHz to 54 MHz. Since it utilizes direct sampling, there’s no need for crystal filters in the K4 or K4D (see Models, back page). For extreme-signal environments, we offer a dual superhet module (standard in the K4HD).  An internal VHF/UHF module is also planned.

High-resolution mini-pan for each receiver

Our advanced fine-tuning aid, with its resampled bandwidth as narrow as +/- 1 kHz, is displayed separately from the main panadapter.  You can turn it on by tapping either receiver’s S-meter or by tapping on a signal of interest.

Simple operation and setup

The K4 features a large, full-color touch display, combined with a rich set of real controls. Per-VFO transmit metering makes split mode completely foolproof. Band-stacking switches and per-receiver controls are both intuitive and versatile, adapting to operating context.  Usage information on these and other features is just one tap away, thanks to our built-in help system. 

Rich I/O complement

The rear panel includes all the RF, analog and digital I/O you’ll need to complete your station.  All K-line accessories are supported, including amps,  ATUs, and our K-Pod station controller. The HDMI video output supports an external display with its own user-specified format.

Full remote control from multiple devices

The K4 can be 100% remote controlled, via Ethernet, from a second K4 as well as a PC, notebook, or tablet. Panadapter data is included on all remote displays. 

Modular hybrid architecture

The K4 adapts to your needs, with three models to choose from:

• Basic K4 with wide-range dual receive
• K4D with diversity receive
• K4HD with a dual superhet module for exceptional dynamic range

You can upgrade or add options as desired, or as new technology becomes available.  This extensibility applies to software as well. The K4’s powerful, fast-starting CPU provides unlimited expansion opportunities.

Fast signal processing

The RF signal chain in the K4 incorporates parallel hardware processing of data streams, including a dedicated DSP subsystem. This, combined with silent, PIN-diode T/R switching, ensures fast CW break-in. Data and speech-processing delays are also minimized.

Standard DSP features include easy-to-adjust, per-mode RX/TX EQ; clean, punchy RF speech processing; full DVR capabilities; and several built-in data decode/encode modes. Direct-sampling technology results in an ultra-flat passband response for clean RX and TX audio. Since the signal chain is software-defined, the DSP can be field upgraded to add new algorithms and operating modes. 

KAT4 ATU

The KAT4 ATU has a nominally 10:1 matching range. It includes 3 antenna jacks, any one of which can be selected as an input for one or both receivers. 

Internal VHF/UHF module  (future option)

An expansion slot is reserved for a high-performance VHF/UHF module, with output of approximately 15 W. This module will support all modes.

Kit version

A no-soldering kit version of the K4 is planned for later release. Builders will learn about advanced radio technology as they proceed. All modules are pre-aligned and tested.

STANDARD FEATURES

Size:  4.5”H x 13.5”W, 10” D

Weight:  Approx. 10 lbs

Supply Voltage:  12-15 VDC

Current:  ~2 A RX, ~18-23 A TX

Frequency Range:  100 kHz - 54 MHz (VHF/UHF range to be determined*)

Stablility:  +/- 0.25 ppm (TCXO)

Modes: CW, SSB, AM, FM, Data

LCD:  7” color; touch & mouse control

Text modes: CW, PSK31/63, RTTY

KAT4 ATU:  10:1+ range; 3 ant. jacks

RX antenna sources:  Up to 5

A-to-D Converter(s): 16 bits
I/O:  USB-A x3, USB-B (two virtual com ports + audio), RS232 (DE9), Ethernet, HDMI. front/rear mic, front/rear phones, LINE in/out, speakers, PTT in, KEY out, paddle, key,  ACC,12 V out.

CW QSK:  Silent, PIN-diode switched

Other: RX/TX EQ, real-time clock,100% remote control including panadapter data, remote antenna switch control*, custom in-box software apps*