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Sale price: $499.00


Amateur Radio's first 24-bit USB Audio Interface

micro KEYER III™ is the world first and the only amateur radio USB interface featuring high dynamic range, 24-bit audio processing chain on all signal stages. It is the most powerful single radio All-In-One USB interface and the only USB interface to fully support digital and voice operation including microphone switching in one box.

With a single USB port, micro KEYER III™ works with any Windows-based logging or control program for CW, Voice, FSK and Digital operation (RTTY, FT8, WSJT, PSK31, SSTV, etc.).

micro KEYER III™ includes a CAT, radio control interface that supports all common standards (RS-232, CI-V, Kenwood and Yaesu TTL), a powerful CW memory keyer using genuine K1EL's WinKey, a Digital Voice Keyer for SSB, two channel audio processing for transceivers with dual receivers, automatic microphone selection, and a buffer/sequencer for amplifier or LNA control.

Compared to 16-bit audio interfaces, or to any USB enabled transceiver, including top of the line transceivers from well known manufacturers (as of autumn 2018), unique 24-bit USB audio processing in the micro KEYER III™ provides advantage in higher dynamic range (>105dB), preserving transceiver performance for audio processing on computer (digital modes), otherwise limited by 16-bit USB audio signal chain.

For connection to the transceiver micro KEYER III™ uses the same transceiver specific DB37 cables as used with original MK, MKII or MK2R+. micro KEYER III™ keeps full backward compatibility for native control from logger programs and is compatible with all accessories made for MKII.

Along with completely new audio, microKEYER III™ brings quite a lot of new features too. For more details or check what's new or different compared to previous MKII model, please see below or read the microKEYER III™ manual.



  • Single USB connection to computer

  • Stand alone operation

  • Complete "Computer ↔ Transceiver ↔ Amplifier" galvanic isolation

  • Internal 24-bit USB Audio

  • Standard USB Audio Class device – no custom driver required

  • Superior asynchronous USB audio data transfer

  • Internal low phase noise LO: -145dBc/Hz @1kHz

  • High dynamic range: 110 dB typical, 105 dB minimum

  • Separate and simultaneously operating Line and Microphone USB Audio Inputs

  • Extremely low noise floor: as low as

  • Additional Optical S/PDIF audio input/output ports

  • iLINK port for digital connection to iLINK enabled devices
    (Station Master, Station Master DeLuxe, SMΩRF) for frequency and data exchange
  • Real-Time audio levels monitoring on built-in color OLED display

  • Silent switching of all audio signals without relays

  • DSP for all analog signals, including microphone inputs

Radio control (CAT):

  • Two, managed (CAT protocol controlled) CAT ports for connecting two loggers or control programs at the same time

  • Up to 57600 Baud with handshake support

  • Integrated level converter for CI-V, FIF-232, IF-232, or RS-232 levels

  • Supports most Elecraft, Icom, Kenwood, Ten-Tec, Yaesu and other radios

  • Simplex SDR receiver tracking feature (Kenwood and Icom protocol supported)

Voice (SSB/AM/FM):

  • Two microphone support for headset and hand/desktop mic

  • Fixed or automatic microphone selection

  • Menu driven settings, no jumpers and trimmers

  • Individually adjustable Gain, Bias, Tone Emphasis and ALC supports seamless use of electret and dynamic microphones combinations

  • Individual “Voice” monitor loop-back for “TX Audio recording”

  • Digital Voice Keyer with nine messages per bank, up to 120 seconds each, unlimited number of banks


Digital (FSK/AFSK):

  • 24-bit, high dynamic range, very low distortion analog inputs

  • Dual channel receive capability

  • Ultra low noise floor for optimal decode level

  • Front panel transmit and receive level control knob

  • Separate Data PTT output for digital audio modes operation (AFSK) with microphone muting

  • True analog feel, low latency RTTY tuning indicator (crossed ellipses)

  • UART based, zero jitter FSK output

  • Re-sampled standard 45.0 Baud rate for accurate 45.45 Baud HAM RTTY speed

  • Intelligent diddle stuffing for no random gaps between characters

  • Supports data codes with 5/6/7/8 data bits and 1/1.5/2 stop bits

  • Sample accurate support for audio based P-FSK keying

  • Unique, hot switch protected FSK keying

  • Adjustable FSK keying polarity

  • PS/2 keyboard or keypad support for stand alone FSK transmission with type ahead function

  • Nine (9) user programmable FSK memories



  • Genuine WinKey™ v3 chip

  • Front panel speed knob

  • Selectable side tone for external speaker with "paddle side tone only" function

  • Individual side tone for “TX Audio recording”

  • Sample accurate support for audio based Q-CW keying

  • PS/2 keyboard or keypad support for stand alone CW “memory keyer” with type ahead function

  • Nine (9) user programmable memories

  • Logger independent contest auto-numbering (Field Day style)


  • 1 Watt amplifier for monitor/sidetone

  • Main OLED display

  • Isolated, high voltage optoMOS based PA and LNA keying outputs, no relays

  • CI-V output for controlling CI-V compatible Power Amplifiers or other accessories

  • Serial output for controlling stepper motor based antennas

  • User presets to recall all parameters for different logger or control programs

  • Optimized for future “Remote Control Suite” connection

  • Huge filtering for maximum RFI immunity

  • Metal/Aluminum case, powder coated and silk screened

  • Free, no time limit firmware/software upgrades via Internet