Afedri SDR-Net Features

● 100 kHz to 35.00MHz continuous frequency range
● Direct sampling
● DDC - Digital Down-Conversion
● 12- bit 80 MSPS A/D conversion
● Up to 1.85MHz recording and processing bandwidth
● Waterfall display functions, when used with appropriate software
● Recording and playback, when used with appropriate software
● Sensitivity -  MDS -136 dBm at 500Hz bandwidth
● USB 2.0 (Full Speed) interface
● LAN interface for remote access
● Compatible with: Linrad, Winrad, HDSDR, Studio1,  SDR Console
SDR-radio, CuteSDR, SdrDX, Quisk, PowerSDR_mrx
● Powered from USB or external power supply 7-10VDC for AFEDRI SDR-Net rev.3.0
● Dimensions 120mm deep x 78mm wide x 27mm high
● Low cost - $259

AFEDRi SDR-Net v.2.3a HamRadioScience review

AFEDRI SDR-Net rev.2.3a Youtube video, HamRadioScience review

Youtube video: AFEDRI SDR-Net + SDR Console ( (thanks to Mauro).

Youtube video: AFEDRI SDR-Net + SDR Console + DRM (thanks to Mauro)

Youtube video: AFEDRI SDR-Net + CW Skimmer + IC-746pro integration for QRP QSO. (thanks to Vasiliy K3IT)

AFEDRI SDR-Net is a direct sampling Software Defined Receiver (see picture below)  it has ability to send it's received I/Q stream trough two different interfaces:

- Network (LAN)

 - USB

The first versions of the AFEDRI SDR receivers supported only a USB interface

AFEDRI SDR-Net has the following specification:

Frequency Coverage:

0.1MHz-35MHz:  Short Wave only, standard  configuration

0.1MHz-35MHz & 35MHz-1700MHz:  VHF/SHF  configuration

Per user request the special SDR revision can be assembled that is able to work  in aliased mode (40Mhz-80Mhz or 80Mhz-120Mhz) , in this revision the 30MHz LPF is not assembled and external Band Pass Filters (BPF) have to be added by user.

Noise Figure: ~11dB (for 1MHz-35Mhz range and maximum gain 35dB)*

*input VGA (Variable Gain Amplifier) has variable Gain from -10dB up to +35dB

MDS: -136 dBm at 500Hz bandwidth

Output data format: two 16-bit I/Q channels (audio stereo stream emulation)

Maximum Receiving Bandwidth:

BW = up to 2300kHz (for 2500k samples/s sample rate) -  using Network connection (for AFEDRI SDR-Net Rev.5.0 )

BW = up to 1850kHz (for 2000k samples/s sample rate) -  using Network connection (for AFEDRI SDR-Net Rev.3.0 and up)

BW = up to 1225kHz (for 1333k samples/s sample rate) -  using Network connection (for AFEDRI SDR-Net Rev.2.0 up to 2.3)

BW = up to 460kHz (for 500k samples/s sample rate) -  using Network connection (for AFEDRI SDR-Net Rev. 0.0 and 1.0)

BW = up to 230kHz (for 250k samples/s sample rate) -  using USB connection

RF ADC sampling rate: 80.000MHz


Power Supply Voltage Requirements:

5V (supplied from the PC's USB bus or from external) or  from external power supply able to provide 5VDC +/-0.2V).

7.0-10V DC to the DC power connector.

Power Supply Current Requirements:

- 370mA from USB

- 440mA form external 7.5V power supply (revisions 5.0 short reception) 


- 600mA form external 7.5V power supply (revisions 5.0 VHF/SHF band reception ) 


AFEDRI SDR-Net rev2.1 in Box

AFEDRI SDR-Net (Rev. 5.0) - short wave only, default configuration


The AFEDRI SDR-Net is designed to be connected to Personal Computer (PC) by two alternative interfaces:

1. Ethernet Network connection.

This can now provide up to 2500kHz sample rate for Rev.3.0

2. Full Speed USB

This interface is identical to the one in earlier AFEDRI SDR versions. It sends  to PC two quadrature channels I/Q with sample rate up to 250k samples per second 16-bit each channel

You can download following audio files recorded in Winrad:

- I/Q with 1333.333 ksamples/s sample rate - Network


- I/Q with 500 ksamples/s sample rate - Network

- I/Q with 444 ksamples/s sample rate - Network

- I/Q with 250 ksamples/s sample rate 14Mhz band - USB

- I/Q with 250 ksamples/s sample rate 7Mhz band - USB


From PC point of view, the SDR-Net can be used alternatively as:

1. Network device using two IP protocols: TCP and UDP.

- TCP protocol is used to control the SDR parameters.

- UDP protocol is used to send received I/Q stream from SDR to PC

2. Or exactly like the earlier AFEDRI SDR - USB Composite Device, that contains two USB functions:

All the USB functionality of the AFEDRI SDR-Net is identical to the earlier AFEDRI SDR, the only difference being in USB Audio Device realisation - it this case it uses a non standard  sample rates, for audio, that is result of an integer division of main clock frequency 80.0Mhz.

For more information about USB functionality of the device please read AFEDRI SDR description.

Listed below are the new feature that have been added with network interface.

When the AFEDRI SDR-Net is connected to a PC using network interface, it is compatible with the following PC SDR software:  Linrad, Winrad, HDSDR, Studio1, SDR Console (SDR Radio), CuteSDRSdrDX,  Quisk, ghpsdr3/QtRadio, PowerSDR_mrx

In addition to this there is software plugin - SDR Network Control Box plugin , that can be used with Winrad, HDSDRStudio1, this allows control of the AFEDRI SDR parameters (frequency, RF gain/attenuation etc...) and reception of the UDP I/Q data stream.

The SDR Network Control Box software can be used as stand alone application  and/or as plug-in for Winrad/HDSDR software (under Windows). This enables the SDR's frequency to be displayed and changed directly from Winrad GUI (please check my Download page).

When working together with Linrad or SDR-Radio software - no additional software or plug-ins are required - you need only to configure this software as you would for using with it with an SDR-IP receiver.

AFEDRI SDR-Net can be used together with MAP65-IQ software when working with Linrad or SDR-Radio software.

SDR Ntetwork Control Box screen-shot.

The SDR Control software was written using Qt Cross-platform application framework from Nokia, so both Windows and Linux software versions can be compiled and have similar Graphical User Interface (GUI) under both operating systems .




AFEDRI SDR-Net is based on same AFEDRI8201 integrated circuit, like AFEDRI SDR of previous revisions, so you can get more information from AFEDRI SDR description page:

Please see the picture below:

There is short block diagram description:

LPF - Low Pass Filter, in default configuration is using as anti-aliasing filter for from DC to ~28MHz (or any frequency located below Nyquist limit).

Can be easily replaced by band-pass filter (BPF) for desired band in under-sampling acquisition mode when received signal is lying over Nyquist frequency (for example 50MHz, 70MHz band, 108MHz). I tested undersampling mode with this receiver on WFM band (88-108MHz), there is some degradation in sensitivity, so it will be better to add external low noise amplifier (LNA) for DX SWL on WFM band.

VGA - Variable Gain Amplifier, it is built using AD8369 IC from Analog Devices, and adjusted in in this design to give amplification/attenuation of input signal from -10dB up to 35dB.

RF Switch - is used in VHF/SHF SDR versions to switch analog  signal path between HF VGA and VHF Front End.

VHF/SHF Front End - Analog Font End chip for VHF/SHF band, based on R820T2 chip (like in RTL dongles)

HPF - High Pass filter for VHF/SHF bands R820T2 front End chip

TCXO - Thermal Compensated Crystal +/- 0.5ppm Oscillator, used as reference oscillator for R820T2 Front End chip

VHF/SHF Power Switch - used to switch on or off 3.3V voltage for R820T2 Front End (when VHF/SHF band is enabled)

DDC Front End - i.e Analog Front End is built on AFEDRI8201PBF integrated circuit, it is heart of SDR, that providing Input RF signal ADC sampling, mixing and digital filtering, base-band signal data is outputs through specific serial interface, that very similar to I2S but not 100% compatible, for example used in my design CPU, need external help from CPLD, to accept data incoming data. More information about you can find in datasheet. Please pay attention that this device is not recommended  by Texas Instruments for new design, but there is many way to achieve this integrated cuicuits from different sources. And I am sure HAM radio society can use it in their applications.   For example I have some quantity of AFEDRI8201PBF in my stock.

FPGA - main function of this device to convert AFEDRI8201 base-band (output data) serial protocol to Serial or Parallel data transfer protocol, that can be received by used in design CPU.

CPU - it ARM Cortex-M3 architecture microprocessor - STM32F207VC (or STM32F207VC), from ST Microelectronics, it controls Analog Frond End by additional SPI control channel, receive processed base-band data from Front End and transfer it to PC using Network interface or USB link and software USB Audio Device and HID device emulation.

Ethernet (RMII PHY) - Ethernet physical layer transceiver, working as interface between LAN (network) and CPU

Power Supply - Whole receiver is supplied from 5V voltage of USB line, and there is three voltages +1.8V -digital, 3.3- digital and 3.3V analog, that generated from single supply voltage.

External Power Supply - Is used as alternative power supply from external DC source, like battery or transceiver power supply, it is  switched DC/DC power supply the SDR. Can work from external sources that gives DC voltage in range 7.5V-15V

Power Switch - automatically switches between USB or external voltage source.

Optional LCD - there is optional parallel LCD interface exists in SDR, LCD is not supported by current firmware yet, cause I am not sure do someone really need it, but can be easily implemented in the future on user request.

The full AFEDRI SDR-Net schematic  can be found on my Download page.


The mechanical size of the AFEDRI SDR-Net PCB is same like for AFEDRI SDR: 120x73mm. It was designed for installing in one two of aluminum  boxes  manufactured by Hammond the manufacturer part number of boxes is:

Second one has biggest height.

AFEDRI SDR-Net rev. 2 in 1455J1201 box

There is lot of files on my download page, software sources and  firmware for your attention.

You can visit also Yahoo AFEDRI SDR user group

Any question? Please ask me by email. alex(*)

- to really send me email - please replace (*) by @ :-) , and please put in email subject

Please check it periodically for latest version.

Further information will be later.