FLEX-8400 SDR Transceiver


1st delivery in August 2024.

The FLEX-8400 offers the latest direct sampling SDR technology at an economical price for the general HF/6m operator, yet it offers great performance for chasing DX and contesting.

Available in August 2024, contact us to pre-order your new FlexRadio!

3,145.48 $3,536.21 $

  • EUR: 2,890.00 € - 3,249.00 €
  • SEK: 32 718 kr - 36 782 kr

The FLEX-8400™ allows use of up to two 7 MHz spectrum waterfall displays and independent receivers to revolutionise your view of the bands. Its two receivers can be placed simultaneously on any band and mode with instant QSY between VFOs. Digital mode and remote operation are a dream.

Supporting Adaptive Predistortion

The FLEX-8400™ is designed for the ham who is looking to operate the radio from a PC, laptop, Maestro™, Mac or iOS client — either local or remote. You get 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. The FLEX-8400 puts leading-edge technology is in your hands.

FlexRadio’s industry-leading SmartSDR™ software offers compatibility across the entire FLEX-8000 Signature Series family to deliver continuous leveraged software enhancement. And you can use the latest SmartLink™ technology to access your radio virtually anywhere from any SmartSDR compatible client with only a login and password — even your iPhone.

FLEX-8400 Features

  • 100W PEP HF-6m operation
  • All modes/all bands
  • Integrated Remote Operation with a Maestro™, iPad®, iPhone® or PC/Laptop
  • 2 Independent Band / Mode Receivers
  • Full Duplex Cross-Band Operation
  • Receive-Only Port
  • Transverter Port
  • Direct Sampling SDR 122.88 Msps – 16 bit
  • 115 dB 2kHz RMDR
  • >155 dB Dynamic Range
  • Integrated Automatic Antenna Tuner
  • 10 MHz Reference Input
  • Integrated GNSS receiver with antenna maintains radio frequency with no adjustments
  • Optional GPSDO Option for ultra high frequency precision and accuracy
  • Optional MARS/CAP/SHARES TX Expansion Module

Plug & Play Remote*

  • No complex setup required
  • Operate anywhere, any time
  • Use a Maestro, Mac, iPad, iPhone or Laptop
  • Across the country or across the world

Anywhere, Anytime, From Any Of These Devices

With SmartLink and a FLEX-6400 you can operate your radio from almost anywhere! Just take an iPhone, iPad, Laptop, or Maestro with you and instantly connect to your radio using an Internet connection.

Best in Class Performance

  • 115db RMDR
  • No listening fatigue
  • Ultra-Low Phase Noise
  • Full Break-in QSK CW
  • Brick Wall Filters
  • Stunning transmit audio

Backed by an Amazing Suite of Software

  • SmartSDR for Windows
  • SmartSDR for Mac
  • SmartSDR for iOS
  • SmartSDR CAT
  • DAX

*SmartLink Remote Requires SmartSDR V2.x License or Later. Requires an Internet connection.

FLEX-8400 Specifications


  • Independent Band/Mode Receivers (Max): 2
  • 1/2 kHz Reciprocal Mixing Dynamic Range (RMDR): 110/115 dB
  • ADC Bits/Sampling Rate: 16/122.88 Msps
  • Frequency Coverage: 30 kHz-54 MHz
  • Amateur Band Preselectors: 3rd Order
  • Cable-less Digital Audio (DAX/DAX IQ) Channels: 2/2
  • Receive Only Ports (Base/Including XVTR Port): 1/2
  • Full Duplex RX/TX Operation

Spectrum / Waterfall Display

  • Spectrum/Waterfall Displays (Max): 2
  • Spectrum/Waterfall BW (Min/Max): 5 kHz–7MHz
  • Spectrum Dynamic Range (Max Zoom): >145 dB
  • Spectrum Resolution Bandwidth (Min)5.85 Hz


  • 160m-6m Transmitter Output: 1-100W(25W AM)
  • Harmonic Suppression (Typ): < -60 dBc
  • Transverter Ports: 1
  • Transverter Frequency Coverage/Power: 100 kHz – 54 MHz/0 to +10 dBm
  • Integrated Automatic Antenna Tuner Range: 3:1 SWR
  • Optional Continuous MARS/CAP Coverage with Extended Transmit Filter
  • Integrated Adaptive Pre-distortion


  • Integrated Remote Operation (SmartLink)
  • Maestro, PC, Mac, iPhone, & iPad Client Options
  • Integrated 12-channel GNSS Receiver, TTFF (COLD) <35s: GPS, Galileo, GLOSNASS, QZSS, SBAS
  • Frequency Stability (0C – 50C): 0.001ppm (GNSS), 0.5ppm (TCXO)
  • Optional GPS Disciplined Oscillator Optional 5 x 10-12 Over 24 Hours
  • External 10MHz Reference Input
  • Power Supply Requirements 13.8 VCDC +/- 15% (14 VDC Nominal)
  • Dimensions 6.74″H (17.1 cm) x 14″W (35.6 cm) x 13.25″D (33.7 cm)

1. RTTY and other digital modes use 3rd party software over DAX channels

FLEX-8400 Whats in the Box

  • FLEX-8400 Transceiver
  • FHM-3 Hand Mic
  • DC Power Cable
  • Ethernet Cable
  • Quick Start Guide

Want to know even more?

Preliminary information. Some features subject to change without notice. Some features may be in future firmware releases.

SKU: FLEX-8400 Categories: , Tag:
Weight 6.4 kg
Dimensions 46 × 44.5 × 29.5 cm


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