FLEX-6400 A Real SDR for Every Operator

Both the FLEX-6400™ offers the latest direct sampling SDR technology at an economical price for the general HF/6m operator yet they offer excellent performance for chasing DX and contesting. The FLEX-6400 model is designed for the Ham who wants to operate the radio exclusively as a server from PC, laptop, Maestro, Mac, or iOS clients – whether local or remote.

Both 6400-family models (FLEX-6400 and FLEX-6400M) share the same game changing band awareness, industry leading phase noise performance, brick wall filters, and legendary audio performance to deliver you the most fun across a wide variety of operating styles.

With a PC, laptop, or Mac client you can utilize up to two 7 MHz spectrum/waterfall displays and independent receivers to revolutionize your view of the bands. Its two receivers can be placed simultaneously on any band and mode with instant QSY between VFOs. Digital mode operation is a dream with no sound cards, cables or boxes needed.


FLEX-6400 Feature Highlights

  • Native Remote Operation: Using Maestro, PC, Laptop, iPad or iPhone
  • SDR Architecture: Direct Sampling
  • Reciprocal Mixing Dynamic Range (RMDR): 116dB
  • Independent High Performance Receivers: Two (2)
  • Maximum Panadapter Bandwidth: 7 MHz
  • Radio Control Surfaces: Ergonomic tactile controls with touch screen interface
  • Integrated Display: 8-inch 1920×1200 IPS Display
  • External Display: 1920×1200 WUXGA via HDMI interface
  • Antenna Connectors: SO-239×2, BNC XVTRx1, BNC RX-INx1
  • Wideband Frequency Coverage: 30 kHz – 54 MHz
  • Transmit Frequency Coverage: 160-6m amateur bands, 100W nominal output
  • Transverter IF Frequency Coverage: 100 kHz – 54 MHz
  • Full Duplex Operation: Yes
  • Digital Audio Exchange (DAX) Channels: Two (2)
  • DAX IQ Channels/Bandwidth per Channel (DAXIQ): Two (2)

Receiver Specifications

  • Receiver Architecture: Direct Digital Sampling
  • Spectral Capture Units (digitizers): One (1)
  • Maximum Slice Receivers: Two (2)
  • ADC Resolution: 16-bits
  • ADC Sampling Rate: 122.88 Msps
  • Wideband Frequency Coverage: 30 kHz – 54 MHz
  • DAX IQ Channels / Bandwidth Per Channel: Two (2)
  • DAX Audio Channels: Two (2)
  • Amateur Band Preselector Coverage: 3rd order
  • 1/2 kHz Reciprocal Mixing Dynamic Range (RMDR): 110/116 dB

Spectrum/Waterfall Display Specifications

  • Maximum High Resolution Spectrum Displays: Two (2)
  • Panadapter Bandwidth: 5 kHz – 7 MHz
  • Spectrum Dynamic Range (max zoom): > 145 dB
  • Spectrum Resolution Bandwidth (min): 5.85 Hz
  • Integrated Touch Panel Display Size (diagonal)1: 8″ (20.3 cm)
  • Integrated Display Resolution1: 1920×1200
  • External Display Resolution/Connection1: 1920×1200/HDMI

Transmitter Specifications

  • Transmitter Architecture: Direct Digital Up-conversion
  • Modulation System: Digital Low Power at Carrier Frequency
  • RF Output Power: 1-100W nominal SSB, CW, FM, RTTY, Digital; 1-25W nominal AM
  • Amateur Band Coverage at Rated Power Output: 160m – 6m
  • Transverter IF Output Power: +0 dBm Typical; +10 dBm max
  • Transverter IF Frequency Coverage: 100 kHz – 54 MHz
  • DAX Transmit Channel: Yes
  • Harmonic Suppression: < -60 dBc typical
  • Transmit Bandwidth: Default 100-2900 Hz (Variable 50-10000 Hz)
  • Microphone Connector: Pseudo Balanced 1/8″ TRS
  • Microphone Impedance: 600 Ohms Nominal (200-10kΩ)

Optional Antenna Tuner Specifications

  • Matching Range 80m – 10m: Optional, 8.3 Ohms – 300 Ohms
  • Matching Range 160 and 6m: Optional, 16.7 Ohms – 150 Ohms

General Specifications

  • USB 2.0 Ports (peripheral control): Two (2)
  • Internal 10 MHz Reference Clock Stability: 0.5ppm TCXO (0-50C)
  • Emission Modes: USB, LSB, CW, RTTY2, AM, Synchronous AM, FM, NFM, DFM, FreeDV2
  • Frequency Resolution: 1 Hz min.
  • Antenna Connectors: SO-239×2, BNC XVTRx1, BNC RX-INx1
  • Antenna Impedance (w/o tuner): 50 Ohm Unbalanced


  • Power Supply Requirements: +13.8V DC nominal ±15%
  • Current Drain (Receive/Transmit Max): 1.7A / 23A @ 13.8V


  • Height: 6.74″ (17.1 cm) with feet
  • Width: 14.0″ (35. cm)
  • Depth: 13.25″ (33.7 cm)
  • Operating Temperature: 0 to +50 degrees C; +32 to +122 degrees F


  • Antenna Tuning Unit (ATU); 3:1 SWR
  • GPS Disciplined Oscillator; 5×10-12 over 24 hours
  • MARS/CAP Coverage Filter Bank
  • ThumbDV module for D-Star mode
Specifications subject to change without notice.
 1FLEX-6400M model.
 2RTTY and other digital modes requires 3rd party software over DAX channels.