Note
The FLEX-6300 is a software-defined transceiver and the entry-level model in FlexRadio Systems' 6000 Signature Series. It is designed as a simpler and more economical SDR option.
The FLEX-6000 Signature Series scales in performance from the entry-level FLEX-6300 to the top-tier FLEX-6700, with the primary differences centered on receiver capacity, spectral visibility, and hardware integration. Here is a summary of the differences between the three models.
Receiver and Spectral Performance
The FLEX-6300 provides a foundational experience with two slice receivers and two panadapters, allowing for the monitoring of two bands simultaneously with a maximum panadapter bandwidth of 7 MHz. Stepping up to the FLEX-6500 doubles this capacity to four slice receivers and four panadapters, while also increasing the maximum panadapter bandwidth to 14 MHz. The FLEX-6700 represents the peak of the line, utilizing two independent Spectral Capture Units (SCUs) to support eight slice receivers and eight panadapters.
RF Handling and Filtering
A significant hardware distinction lies in how these radios handle busy RF environments. The FLEX-6300 lacks internal amateur band preselectors. In contrast, the FLEX-6500 includes integrated contest-grade preselectors covering 160m through 6m (excluding 60m). The **FLEX-6700** extends this protection even further, providing preselector coverage from 160m all the way through the 2m band. Additionally, the 6700 features a multi-stage pre-amp and increased spectral sensitivity through extra zoom levels.
Frequency Coverage and Accuracy
While all three models cover the standard 160m to 6m amateur bands at 100W, their wideband reception and extended frequency capabilities differ. The FLEX-6300 receives up to 54 MHz, while the FLEX-6500 and FLEX-6700 both reach 72 MHz. Only the FLEX-6700 includes native coverage for the 2m band (135–165 MHz). For frequency stability, both the 6500 and 6700 offer an optional GPSDO for ultimate accuracy, whereas the 6300 relies on its standard TCXO.
Hardware Integration and Connectivity
The physical build and connectivity also evolve across the family. The FLEX-6300 is the most compact unit and offers an optional antenna tuner (ATU), whereas the FLEX-6500 and FLEX-6700 are larger rack-mountable units with the ATU integrated as standard. The higher-end models also provide more robust audio options, including balanced XLR/TRS microphone connectors that are not present on the 6300.
6300 Features
– Software-Defined Architecture: The radio is highly integrated with SmartSDR for Windows software, which runs on a user-supplied PC and is updated several times a year with new features and bug fixes.
– Direct Sampling:** It utilizes an analog-to-digital converter (ADC) that produces 122 million 16-bit samples per second (Msps), sampling the RF spectrum up to 54 MHz.
– Includes a single Signal Capture Unit (SCU).
–Supports up to two panadapter/waterfall displays and two receivers simultaneously.
– Operates in "wide" mode across the spectrum as it does not include preselectors.
– Spectral Visualization: Allows users to visualize a large swath of the spectrum and click on any point to demodulate signals in SSB, CW, AM, or FM modes.
– Digital Processing: Uses a Xilinx Virtex-6 FPGA for high-speed DSP operations and a DaVinci Processor (ARM Cortex-A8) for filtering and signal demodulation.
– Connectivity: Communicates with the PC via an Ethernet connection (minimum 100 Mb/s) and uses custom DAX drivers for two-way digital audio.
Specifications
– Frequency Coverage: Receive: 0.03–54 MHz; Transmit: 160, 80, 60, 40, 30, 20, 17, 15, 12, 10, and 6 meter bands.
– Power Output: 100 W (CW/SSB/FSK/FM); 25 W (AM).
–Modes: SSB, CW, AM, synchronous AM, RTTY, FM.
– Power Requirements: Receive: 1.7 A typical; Transmit: 23 A max at 13.8 V dc ±15%.
– Receiver Noise Floor (MDS): –121 dBm (preamp off), –125 dBm (10 dB preamp), –136 dBm (20 dB preamp).
– Image Rejection: >80 dB.
Optional Accessories
6300-ATU: An optional internal automatic antenna tuner.
FlexControl: A USB tuning knob for users who prefer a physical dial over mouse-based tuning.
