FlexRadio 6400

FlexRadio 6400



The FLEX-6400 is a 100W HF transceiver for the shortwave bands from 160 to 10m, plus the 6m band. Two completely independent receivers are available, an important prerequisite to work DX in split mode or to observe other bands and modes during a contest. Full duplex crossband operation is also possible.

The receivers are designed as direct sampling SDR receivers. A sampling rate of 122.8 MHz is used, the AD converter has a word size of 16 bits. This results in an excellent RMDR value of 115 dB (at 2 kHz distance). As a visible result of this high-end digital technology, the user has a spectrum width of up to 7 MHz, more than sufficient to observe several amateur radio bands simultaneously. The frequency range of the receiver is from 30 kHz to 54 MHz, the transmitter is limited to the amateur radio bands. The preselector with 3-pole band filters provides a very good large signal selectivity. A low-noise oscillator contributes significantly to the good receiver data. For exceptionally high requirements a 10 MHz reference clock input is available, which can be driven by an optional GPSDO. For friends of VHF bands, a transverter output and an RX input are available, enabling operation on higher bands with an external transverter.

The transmitter of the FLEX-6400 offers 100W transmit power (PEP, 25W AM), the suppression of unwanted by-products is better than 60dBc. The transverter output can be set from 0 to +10 dBm. The transmitter is limited to the amateur radio bands provided in the respective region. An optional antenna tuner can automatically correct mismatches up to 3:1 SWR (ATU option).

As with all FlexRadio transceivers, the main focus is on easy to handle remote control. The FLEX-6400 can be operated with any Windows PC, iPhone or iPad. In addition, the Maestro console is available which can access the transceiver via WLAN or wired Ethernet. The ‘SmartSDR’ software in version 3 offers a special feature: The ‘multiFlex’ function offers the possibility to use a transceiver of the 6000 series with a second user at the same time. This makes ‘Multi-Op/Single-Radio’ operation very easy, even over long distances.

The control panel is equipped with a brillant touch screen with 1920×1200 pixels resolution. A wide range of functions can be accessed via this screen, such as frequency setting or selecting the operating mode. The traditional controls are intentionally placed at large distances on the front panel for easy and clear operation even in hectic contest situations. The fact that almost all of these buttons have only one function contributes to the very clear and easy to learn operation of Flexradio transceivers.

Remote Operations

Every FlexRadio model – with or without front panel – can be easily remote controlled. The following options are available:

  • SmartSDR Software on Windows-PC
  • SmartSDR for IOS on iPhone or iPad
  • Maestro Console

This remote control can be done via the local network in a building, but also via the Internet from a great distance. No matter where you are – you can still work that rare DX station from your own station when you are sitting in the hotel! With the latest version V3 of the SmartSDR software it is even possible to operate a transceiver with two remote operators at the same time. Any mix of the above mentioned devices can be used – a PC, iPhone/iPad or the Maestro console.


Included in shipment

  • FlexRadio 6400 (without ATU)
  • FHM-2 Microphone
  • DC Cable Powerpole, other side open
  • RJ-45 Ethernet Cable
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