Dual-mode SDR transceiver: stand-alone and PC-based
FDM-DUO is an SDR transceiver that can operate stand-alone like a traditional radio or connected to a computer, unlocking the possibilities offered by SDR technologies.
Stand-alone RX specifications
- Frequency range: 10 kHz – 54 MHz.
- Direct-sampling receiver operating at 122.88 MHz, ADC: LTC2165 16 bit.
- DDC (Digital Down Converter) implemented with Xilinx Spartan 6 FPGA.
- Stand-alone demodulator filters implemented with ARM STM32F4 microcontroller with FPU.
- Demodulation: CW, CWR, LSB, USB, AM, narrow FM.
- Selectable LSB and USB filters: from 1600 Hz to 3100 Hz in 100 Hz increments plus values of 4000 Hz, 5000 Hz and 6000 Hz.
- Selectable AM filters from 2500 Hz to 6000 Hz in 500 Hz steps.
- Selectable CW filters: 2600 Hz, 1500 Hz, 1000 Hz, 500 Hz, 300 Hz and 100 Hz plus 4 CW peak filters applied after the 100 Hz filter to obtain an overall filter bandwidth of 20 Hz.
- Selectable FM filters: narrow, wide and data.
- Pitch setting: up to 1 kHz in 10 Hz steps.
- RIT function.
- Three audio volumes: main, auxiliary and sidetone.
- Squelch: 10 selectable positions.
- Gain control: automatic (AGC) and manual, with adjustable threshold.
- Noise reduction: 10 selectable positions.
- Noise blanker: 10 selectable positions.
- Automatic notch: 2 selectable positions.
Stand-alone TX specifications
- Supports bands from 160 m to 6 m.
- Modulation and filtering implemented with ARM STM32F4 and DDS AD9957 with 368.64 MHz clock.
- Modulations: CW, LSB, USB, AM, narrow FM.
- Microphone input (ADC 48 kHz @ 16 bit) with selectable gain (+/- 12 dB). Selectable TX bandwidth. Adjustable compression gain.
- Key and paddle input for CW operation, supports Iambic A and B, adjustable CW speed for paddle, adjustable CW delay.
- Unfiltered 0 dBm output on SMA connector (can be used as test equipment or as a digital RF generator).
- Up to 5 W output power on all bands plus maximum selection (for example 8 W at 14 MHz).
- PTT output for driving external amplifiers.
Main features
- VFO A and VFO B, with dedicated frequency, step and mode.
- 200 memories with dedicated frequency, step, mode and alphanumeric label.
- QuickMem function: up to 20 recallable memories for band selection (memories 180 to 199).
- QuickStep function: allows the step to be changed quickly without modifying the step of the VFO or of the selected memory.
- Tune function to facilitate antenna tuning with the external antenna tuner.
- VFO A = VFO B function.
- VFO to MEM (save) and MEM to VFO (load previous save) functions.
- Stand-alone split function, VFO A for RX and VFO B for TX.
- 2 customizable keys (F4 and F5) with various functions: CW message sending, split management, tuning knob lock, CW/CWR selection.
- 2 frequency entry modes: by step or digit by digit.
- Built-in CW decoder.
- Color LCD programmable with RGB values for the various operating modes (RX, TX, PC remote control, …).
- All programmable components (ARM RX, ARM TX, FPGA Flash, user interface microcontroller and USB controller) are upgradable.
General specifications
- Antenna connectors: RTX SO-239, RX SO-239.
- USB CAT control interface with FTDI controller, also handles RTS and DTR signals for transmitting.
- Proprietary EXTIO interface for connecting accessories.
- 10 MHz reference input on SMA connector.
- Power supply: 2.1 mm jack, voltage 13.8 Vdc.
- RX consumption: typical 500 mA @ 13.8 Vdc.
- TX consumption: <2.2 A @ 13.8 Vdc (5 W output).
- Dimensions: width 180 mm, depth 155 mm including knob and connectors (enclosure only 130 mm), height 70 mm.
- Weight: 1.2 kg, shipping package 2.2 kg.
Operating specifications with the FDM-SW2 software
- Up to 4 simultaneous virtual receivers in single-channel mode.
- Up to 8 simultaneous virtual receivers in dual-channel mode.
- Dedicated audio channel for each virtual receiver.
- Dedicated CAT channel for each virtual receiver.
- Supports connection with external programs using virtual serial ports and virtual audio cables.
- USB IQ streaming selectable in two main modes: stand-alone, 192 ksps single channel and 192 ksps double channel; remote, 384 ksps, 768 ksps, 1536 ksps, 3072 ksps, 6144 ksps in single-channel mode and 384 ksps in dual-channel mode.
- Remote split operation, VFO A for RX and VFO B for TX. TX frequency and TX mode are managed by FDM-SW2.
- File playback function. CW message sending function. Advanced transmit function with equalization, VOX, compressor and filter capabilities.
- CW Skimmer integration management (DX spot display and tuning capability).
- Direct digital modulation via the FDM-DUO USB sound card based on a CMedia chipset digitally interfaced with an ARM microcontroller.
