QO-100 (Eshail-2) Satellite transceiver options.

QO-100 (Eshail-2) Satellite transceiver options.

Click on Image to enlarge

SDR Options

And here is a more conventional way

Conventional MIXER upconverter

Link to http://www.giga.co.za

How to Create a Linear Transponder using a RTL Dongle and HackRF with Gnu Radio.

How to Create a Linear Transponder using a RTL Dongle and HackRF with Gnu Radio.

I wanted to test the concept of a linear Transponder and how difficult would it be to build it with conventional components.

Hardware Configuration

Hardware required to build the Transponder.

1. SDR IQ demodulator with rtl dongle (RF In)
2. SDR IQ DSP processing system. Gnu Radio (DSP processing)
3. SDR IQ Modulator. HackRF (RF Out)
4. Background management system. (OBC) for additional telemetry.

Software required for Transponder.

1. SDR IQ demodulator. rtl dongle (RF In)
2. SDR IQ DSP processing system. Gnu Radio (DSP processing)
3. SDR IQ Modulator. HackRF (RF Out)
4. Background management system. (OBC)

Video of working Transponder.

Gnu Radio.

Transponder Block Diagram

RTL SDR Block.

RTL-SDR Source

Low Pass Filter Block.

 

Low Pass Filter Block

AGC Block.

AGC Block

Power Squelch.

Power Squelch

Osmocom Sink. (HackRF)

Osmocom Sink (HackRF)

FFT. (Spectrum View of input)

FFT Spectrum View

REF: Power point Slides at AMSAT SA

Ref:Source code is available on Github Version 4

Setting up my hackrf on ubuntu 17.10

Setting up my hackrf on ubuntu 17.10

sudo apt-get install gcc-arm-none-eabi

sudo apt install cmake
sudo apt install hackrf

if the hackrf command above did not work then follow the following steps


git clone https://github.com/mossmann/libopencm3.git
cd libopencm3/
ls
cd ../hackrf/
ls
git submodule init
git submodule update
cd firmware/libopencm3/
make
sudo synaptic
xhost +
sudo synaptic
make
sudo apt-get install gcc-arm-none-eabi
cd hackrf/firmware/hackrf_usb/build
mkdir build
cd build
cmake ..

hackrf_spiflash -w hackrf_usb.bin

Update firmware
hackrf_spiflash -w hackrf_one_usb.bin
hackrf_info

hackrf_cpldjtag -x hackrf_cpld_default.xsvf
hackrf_info