Your First HF Radio Should Make FT8 Feel Effortless

The FLEX-8400 gives new hams a wide open window into HF, direct sampling SDR performance built in, at a price that makes getting started make sense. No sound cards. No cable chase. No guessing.

Made for the Mode Everyone’s Talking About

FT8 has become the way most new hams make their first contacts. It doesn’t require Morse code skill, and it works even when conditions are marginal. Because the FLEX-8400 is a direct sampling SDR, digital modes run straight through the radio’s own audio path, no external sound card, no extra cables, no levels to fuss with. Open SmartSDR, click a signal on the waterfall, and you’re decoding. Your first FT8 contact can happen the same day the radio arrives.

And it’s just as capable everywhere else you’ll want to operate. Legendary FlexRadio transmit audio and 115 dB RMDR keep SSB clean and readable, full break in QSK CW and ultra low phase noise give CW operators the fast, quiet keying they expect, RTTY runs through the same clean digital path with brick wall filtering for crowded contest bands, and if you want to try RADE, the newest digital voice mode from the FreeDV project, this radio’s clean receiver and native digital audio path make it a great platform for that too.

What this means in practice

See the whole band at once on the waterfall display, so you can spot activity visually instead of scanning blind

Click directly on a signal to tune to it, no dial spinning required

The radio’s clean receiver front end (115 dB RMDR) means a strong nearby station won’t bury the weak one you’re trying to work or decode, on any mode

Digital modes run straight through the radio’s own audio path, so there’s nothing extra to buy or plug in

New to the hobby? You don’t need a wall of boxes or a technician’s toolkit to get this radio on the air.

Plug in power, connect Ethernet, load SmartSDR (it’s free), and you’re transmitting. SmartSDR is the software that becomes your radio’s front panel, it shows you the band, your signal, and every control, right on your screen. There’s no separate hardware interface to learn first.

Performance That Grows With You

Direct Sampling SDR (122.88 Msps, 16 bit): The radio digitizes the entire HF band at once rather than tuning to one frequency at a time, which is what gives you the full band waterfall view

115 dB RMDR (Reciprocal Mixing Dynamic Range): In plain terms, this is what keeps a loud station down the band from drowning out a weak one you’re trying to work, especially useful during contests or crowded FT8 windows

Brick wall filters: Sharp digital filtering that lets you isolate one signal cleanly, even in a packed band, without static bleeding in from next door

Two independent receivers: Listen to two bands or modes at once, useful once you start chasing DX or checking a second band while you work FT8 on the first

100W output, all modes, all HF bands plus 6m: Room to grow into SSB, CW, and contesting whenever you’re ready, without needing new hardware

Operate from Anywhere!

With SmartLink, your shack goes wherever you go. Log in from a laptop, iPad, iPhone, or the Maestro control console and your radio responds like you’re sitting in front of it, whether you’re across town or across the world. No port forwarding, no network setup, just a login and a connection.

(StarLink and CGNAT ISPs may require customization – talk to your ISP)

*Mac OSX SmartSDR and iOS SmartSDR clients are provided by third-party vendors

  • Comes with the latest SmartSDR v4 Basic firmware
  • 100W PEP HF-6m operation
  • All modes/all bands
  • Integrated Remote Operation with Maestro, PC/Laptop, Mac, IPad® or iPhone®
  • 2 Independent Band / Mode Receivers
  • Full Duplex Cross-Band Operation
  • Transverter Port
  • Receive-Only Port
  • Direct Sampling SDR 122.88Msps – 16 bit
  • 115 dB 2kHz RMDR
  • >155 dB Dynamic Range
  • Optional Antenna Tuner
  • 10 MHz Reference Input
  • Integrated GPSDO Option for ultra high frequency precision and accuracy
  • Optional MARS/CAP/SHARES TX Expansion Module

Specs

  • Weight: 240 oz
  • Width: 18 in
  • Depth: 19 in
  • Height: 12 in

Receiver:

  • Independent Band/Mode Receivers (Max): 2
  • ½ 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): ½
  • Full Duplex RX/TX Operation

Transmitter

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

General

  • Modes1 SSB, CW, AM, SAM, FM, RTTY, DIGITAL
  • Integrated Remote Operation (SmartLink)
  • Maestro, PC, Mac, iPhone® and iPad® Client Options
  • Frequency Stability (0⁰C – 50⁰C) 0.5ppm (TCXO)
  • Optional GPS Disciplined Oscillator (5 x 10-12 Over 24 Hours)
  • External 10MHz Reference Input
  • Power Supply Requirements 13.8 VDC +/- 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.

Plug & Play Remote1

  • 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-8400 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 Mac2
  • SmartSDR for iOS2
  • SmartSDR CAT
  • DAX

1. SmartLink Remote Requires SmartSDR V2.x License or Later. Requires an Internet connection.
2. SmartSDR for Mac and SmartSDR for iOS are optional, 3rd party software for pay options.

FlexRadio does not charge your credit card until your order ships, but we do pre-authorize the full purchase price at the time you place your on-line order.

Due to the price class of a FLEX-8400, your order may exceed your credit card’s daily transaction limit resulting in your order not being completed. In these cases, you may either contact your credit card company and negotiate a different daily purchase limit -OR- you can call the FlexRadio Sales department at 512-535-4713 ext 1 to place your order over the phone where we will not pre-authorize order payment until time of shipment.