AFE822x SDR-VHFx2 (Dual Channel)

AFE822x SDR-VHFx2 ( Dual Channel ) Features

● Synchronized (diversity) or separated (independent) Dual Channel reception mode
● 100 kHz to 35.00MHz and 35MHz to 1450MHz continuous frequency range
● 2-x Direct sampling receivers
● Digital down-conversion
● Dual 12- bit 76.8 MSPS A/D conversion
● Up to 1100kHz recording and processing bandwidth for each channel in dual channel mode or 2.2MHz in single channel mode
● Waterfall display functions, when used with appropriate software
● Recording and playback, when used with appropriate software
● USB 2.0  interface (Full Speed)
● LAN (network) interface for remote access
● Compatible with: Linrad, MAP65, Winrad, HDSDR, SDR Console
SDR-radio, CuteSDR, Studio1, SdrDX, Quisk, PowerSDR_mrx
● Powered from USB or  7-10VDC from External Power Supply
● Box dimensions are 127mm x 78mm  x 27mm (lenght x wide x height)
● Price -  399$ (boxed only)

AFE822x SDR-VHFx2  is a Dual Channel direct sampling Software Defined Receiver  it is composed by AFE822x SDR-Net rev.3.0 + VHFx2 extension board, that allows to have extended reception frequency range.

All main SDR parameters and properties are exactly equal to parameters of AFE822x SDR-Net rev.3.0 plus, in addition to HF frequencies range, possibility to receive signal in VHF/SHF bands.

AFE822x SDR-VHFx2  Dual Channel receiver has the following specification:

Frequency Coverage:

0.1MHz-35MHz (on HF antenna input) and

35MHz-1450MHz (on VHF antenna input)

Dual channel coherent signal is warranted in the next frequency ranges:

0.1MHz-35MHz, 35MHz-450MHz, 1295MHz-1297MHz.

*the coherency also is possible on some frequencies outside listed above limits.

Noise Figure: ~11dB (in 1MHz-30Mhz range and maximum gain 35dB)

~9dB on (on 50MHz band and maximum  LNA+Mix. gain)

~7.3dB on (on 70MHz band and maximum LNA+Mix. gain)

~5.6dB on (in 144MHz-438MHz range and maximum  LNA+Mix. gain)

~12dB on (on 1296MHz band and maximum LNA+Mix. gain)

Output data format:

 1. four 16-bit I/Q channels (in dual channel mode)

 2. two 16-bit I/Q channels (in single channel mode)

Maximum Receiving Bandwidth:

BW = up to 1100kHz for each channel (for 1200 ksamples/s sample rate) -  using Network connection in Dual Channel mode

BW = up to 2100kHz (for 2400k samples/s sample rate) -  using Network connection in single Channel mode

BW = up to 110kHz (for 125k samples/s sample rate) -  using USB connection and Dual Channel Mode

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

 

*Notes: The real sample rate value can be little bit different from the numbers printed above and depends mostly on Main Clock value

 RF ADC sampling rate: 76.800MHz

 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).

 7-10V DC to the DC power connector.

Power Supply Current Requirements:

~ 550mA (when tuned to HF bands)

~ 850mA (when tuned to VHF/SHF bands)

from USB or external 7.5V power supply. Mini-USB Y-cable is used to get power from USB line.

 

 

AFE8220 SDR-VHFx2  is based on the AFE822x SDR-Net plus VHFx2 extension board (see picture below):

VHFx2  rev.1.0 extension board

 

AFE822x SDR-VHFx2  rev.3.1 Dual Channel ( no box, AFE822x + VHFx2 stacked PCBs)

 

 

AFE822x SDR-VHFx2 (Dual Channel) rev.3.1 in 1455J1201 box

 

 Exactly like AFE822x SDR-Net rev.3.0 the AFE822x SDR-VHFx2 is designed to be connected to Personal Computer (PC) by two alternative interfaces:

1. Ethernet Network connection.

2. Full Speed USB

For more information about AFE822x SDR-VHFx2 functionality,  please read AFE822x-Net description.

 

When the AFE822x SDR-VHFx2 is connected to a PC using network interface, it is compatible with the following PC SDR software:

In addition there is software plugin - SDR Network Control Box plugin , that can be used with Winrad, HDSDR  this allows control of the AFE822x SDR-Net/AFE822x SDR-VHFx2  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 for SDR configuration and/or as plug-in for Winrad/HDSDRsoftware (under Windows).

 

The block Diagram of AFE822x SDR-VHFx2  can be found on the picture below:

There is short structure diagram description:

AFE822x SDR-Net related blocks:

LPF - Low Pass Filter, in default configuration is using as anti-aliasing filter for from DC to ~35MHz.

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.

Direct Sampling Receiver Front End - i.e Analog Front End is built on AFE8220 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.   

CPLD - main function of this device to adopt AFE8220 integrated circuit base-band (output data) serial protocol to  communication protocol that is supported by microprocessor.

CPU - it ARM Cortex-M4 architecture microprocessor - STM32F427VC , from ST Microelectronics, it controls DDC chip by dedicated SPI interface and VHF/SHF front ends by two I2C lines, also receives 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  linear power supply, can work from external sources that gives DC voltage in range 7VDC-10VDC

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

VHFx2 extension board related blocks:


RF switch - high frequency SPSD UltraCMOS RF switch (couple of switches are located on the AFE822x SDR-Net PCB and all others on the VHFx2 extension board).

Calibration source - calibration signal circuits used for automatic or manual coherency calibration.

HPF - couple of high pass filters, with corner frequency 35MHz

Reject Filter - Reject filters used to attenuate signals from Broadcast FM stations in the frequency range 80MHz-108MHz 

VHF/SHF Front End - two VHF/SHF based on R820T2 chip used as down converter that feeds signals to DDC stages.

TCXO - high stability Thermal Compensated Crystal oscillator, used as reference signal for VHF/SHF front end embedded pll.

VHF/SHF Power supply - linear low drop out 3.3VDC stabilizer.

 

The mechanical size of the AFE822x SDR-VHFx2 are same as for AFE822x SDR-Net i.e. designed for installing two stacked PCB into aluminum  box  manufactured by Hammond:

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

You can visit also groups.io AFEDRI SDR user group

Any question? Please ask me by email. alex(*)4z5lv.net or alex(*)afedri-sdr.com

- 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.

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