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Balloon Project.

Just wanted to give some feedback regarding the DRA818 module I bought from you. We used it in our high altitude balloon this past saturday hooked up to raspberry pi zero to make a rudimentary sstv came. It worked great! We even got confirmation of perfectly received images in Bloemfontein and Secunda. Unfortunately the actual camera came loose in the payload so most of the images were useless (inside of the payload). But the concept worked great! I used the pi pwm output to generate the sound (through a filter) that was connected to the mic of the dra818 module. PTT was switched with a transistor also from the pi. On the pi I have a bash script that got executed every 5 minutes. It took a picture. Added overlay text, converted to a sound clip with the sstv encoding and then played over the pwm pins. The dra818 module was used at low power setting (think about 400mW?). Also used a diy dipole antenna on the payload (not pictured)

Final prototype:

Next step is to make it smaller and more power efficient, but very happy with the results :)

Anyways, figured you might like some feedback.

Thanks for the shop, have more purchases lined up for payday.

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.

Link to Blog with full details here
Hardware Configuration
Hardware required to build the Transponder.

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

Software required for Transponder.

    SDR IQ demodulator. rtl dongle (RF In)
    SDR IQ DSP processing system. Gnu Radio (DSP processing)
    SDR IQ Modulator. HackRF (RF Out)
    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
Link to Blog with full details here
This projects code is available from Github
This code is working but has lots of place for improvements .(project started 14 Sep 2017) This project will have the files for a Cube Sat Telemetry system Using Raspberry Pi Transmitter Board.

I will be using a External GPS and temperature geometry meter to generate the Telemetry Data. The System will use GPDS and direwolf with Beacon configuration to send System data. The Diarewolf RX will be a RTL dongle withe a sharp Saw or Crystal filter as a front-end. The transmitter and receiver can be configured to be FM repeater as well. Here is a Block diagram of the BACAR Balloon telemetry system.
Link to RF Hat for raspberry pi Alt text
Image of RF transmitter hat 2M band (any frequency from 1 to 500MHZ can be assembled for a band.

Balloon Satellite picture.

More Pictures.

More Pictures

More Pictures
Here is information how to get your Echolink link or Echolink repeater up and running using a Rapberry Pi and Baofeng HT.
Use only low power on Baofeng uv-5r as it could overheat when TX is on two long.

Or you can connect it to Linux Laptop

What hardware do you need.
1) "EASY DIGI" Baufeng UV-5R INTERFACE for laptops, desktops and Raspberry with usb audio. (Easy Digi) Asembled)
2) USB 2.0 To 3d Audio Sound Card Adapter Virtual 5.1 CH.
3)The Raspberry Pi 3 Model B
5) Baofeng power eliminator

Software instelation of svxlink
Download from here
I will add the details how to install and configure the svxlink
Programming ESP8266 ESP-12E NodeMCU Using Arduino IDE

Link to programing details
Configuring my wifi dongle on the Raspberry Pi to connect to my network router.

Configuring my wifi dongle on the Raspberry Pi to connect to my network router.

Generic Wifi dongle used on my Raspberry Pi

I had to get my router details and had to configure the following configuration files.
I wanted to give my Raspberry Pi a spear static IP so I always know what it is on my network.

I edited the following files.


I added the following at the end. I was using WEB encryption and shared key on my router.
Change the details in yellow for your router if you use web encryption with shared key.
use your favorite editor
sudo vi /etc/wpa_supplicant/wpa_supplicant.conf

#Configeration of the file /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
        ssid="MyRouter"  # your router ID
        wep_key0="0123456789123"  # or 13 characters, or a hexkey starting with 0x your key

Save and exit
And the change the following file

Edit the file as follows in the section configuring wlan0
I gave my Raspberry pi a spear static Ip on my network so always now what the ip is and don't use DHCP so I will not know what the Ip will be
use your favorite editor

sudo vi /etc/network/interfaces
auto wlan0
allow-hotplug wlan0
#iface wlan0 inet dhcp
iface wlan0 inet static
address  #Static Ip
netmask # Ip mask of network
gateway # IP gateway of router
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp


And reboot Raspberry Pi  sudo shutdown -r 0

ping your new Ip on Wifi network


And it should now work.
HF Noise monitoring system running from Live Ubuntu Memory stick with fully configured environment.

 HF Noise monitoring system running from Live Ubuntu USB flash drive.

Ubuntu Live Noise Monitoring system with Persistence. 16Gb
I wanted a Preconfigured RF Noise monitoring system that I can run on my Laptop when ever I am not using it for something else.
I made this Ubuntu 16.04 Live memory stick .

This dongle is available from my Shop at

So how dose it work?
Configure your BIOS to boot from USB flash drive and you should then see the following screens.

Just pres enter to continue
If you see the error above just pres Enter  You should then get a screen where you can select how you want to boot your environment Persistent or not.
Select  the Persistent live boot.

Select the Persistent live option.
You could then see a screen for a few seconds looking like this.

Black screen before startup   
This picture is of Ubunto 17.10 The Noise system is on Ubuntu 16.04   

Here is some of the sunscreens of some of the functionality

HF Heat map
 Noise Graphs  (link to a live system)

Posted by Anton Janovsky at 3:41 PM Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest
Labels: Amateur Radio, HF, Interference, Noise, Radio, RF, RFI, South Africa
Thursday, November 2, 2017
How to make a persisnt ubuntu LIve Memeory stick (16GB)
How to make a persistent live Ubuntu USB Memory stick (16GB)

16Gb Flash disk
I wanted to create a boo-table Ubuntu live flash stick that will also keep my last installed applications and not default back to standard when I reboot.

Ubuntu 17.10 Live with all my apps

You need to create two partition fat32 for the Ubuntu instillation from ISO file and a ext4 casper-rw partition for the persistent part. The compleet proses is done with a application called DUS.
Here is the process to install the DUS software
sudo add-apt-repository universe
sudo add-apt-repository ppa:mkusb/ppa
sudo apt-get update
sudo apt-get install mkusb usb-pack-efi
sudo apt-get install mkusb-nox usb-pack-efi

Select the following on the screens.

1) Double-Click on the i option Install(make a boot device):
2) Double-Click on the p option Persistent Live and select the .iso file:
3) Click on the USB drive to make persistent. I want to use my 32 GB one so I mark the radio button:
4) Click Use Defaults to let mkusb choose default:
5) Enter a percentage of the drive to reserve for persistence. Mine is a large (32GB) so I allot only 20% ~ 6GB. The remaining space will be turned into an empty portable drive:
6) Double check very carefully and confirm. You don't want to mess up another drive.

Waite until 'Done' is written go and get some coffie :-)

 Here was my configuration

Cruzer Blade     sdb                                                    14.6G
                 |-sdb4 iso9660 Ubuntu 17.10 amd64         1.4G
                 |-sdb2                                                         1M
                 |-sdb5 ext4    casper-rw                             12.9G
                 |-sdb3 vfat    usbboot                                 244M
                 `-sdb1                                                        1.1M

ref :
HF Noise Monitoring / RF Noise Monitoring system on a Raspberry Pi
« Last post by Anton Janovsky (ZR6AIC) on January 30, 2018, 11:36:00 am »
 RF Noise Monitoring system on a Raspberry Pi
(This system will record RF signals and upload the results to the Server where trending graphs are created)
This system is now also available on Ubuntu live memory stick.
Link to Video
Here link to live system operating at and

This system software is available pre installed on a 16GB SD card from Giga Technology

Raspberry Pi OS with HF monitoring software pre installed

What do I get on the software?

I system that will record 1Mhz band with samples every 2 minutes generating Graphs and Heat-map of the hole 1 to 30Mhz band.

What hardware do I need?

The  100khz to 1.7Ghz HF dongle as in picture below Screenshot of Graph monitoring.

url of link on system http://localhost/hf_noise/graph/1Mhz_Power.php

Link to live system is here

Screen shot of the HF Monitoring system
How does this system work?

Block Diagram of the HF Noise Monitoring system.

How dose the HF Noise Monitoring system work

    The HF noise monitoring system takes a 1Mhz bandwidth samples every 2 minutes using the rtl_power utility and save the measurements in a CVS fie.
    The 2 minute scheduling is done with a Crontab calling a script in the hf_noise directory.
    The RF Samples is taken at a 1Mhz bandwidth from 1M to 30Mhz therefore 29 of  the CVS files is created and gets appended as the measurements is made.
    A Perl script utility is the executed from a cron scedular  to read the 29 CSV files and import there data into a RRD database.
    The RRD database then gets interrogated by another Perl script scheduled by a cronjob to generate the graph Images and and html files and get saved in the Apache web server graph directory witch is the exposed on http://localhost/hf_noise/graph/1Mhz_Power.php
    Link to Live system
    The RRD database will then create the Hourly, Daily,Weekly,Monthly and Yearly averages and   then generates the graphs every 2 minutes according to the parameters passed to Database.
    The generated graphs is then displayed in a php page via a Apache web server with an php plugin on the following url http://localhost/hf_noise/graph/1Mhz_Power.php.
    Trends can then be seen on a graphs over time.
    The heat map is generated by a python script from different CSV files and is saved in the /var/www/hf_noise/images directory and can be accessed on the local web server on the following url http://localhost/hf_noise/images
    Link to live system
    The systems has a static IP by default on Ethernet and on wifi if you have wifi dongle installed. You can change it to your ip

Here is a list of RRD database management tips

    How to backup my RRD db data?
    use rrdtool dump hf_noise.rrd > filename.xml to export the data to XML format.
    How to Restore my RRD db data?
    Transfer the XML dump to the target system. Run rrdtool restore [--range-check|-r] [--force-overwrite|-f] filename.xml filename.rrd to create a new RRD from the XML dump. See rrdrestore for details.
    How to change some of the the RRD db data?
    Use rrdtool dump to export RRD files to XML.
    Open the XML file, find and edit the bad data.
    Restore the RRD file using rrdtool restore.

 How to generate a brand new RRD db?

There is an script in the hf_noise directory called

You can just run this script in the hf_directory sudo ./

Here is the details of the scrip.

    rrdtool create  hf_noise.rrd --start now-2d --step 120 DS:1Mhz_Power:GAUGE:120:-50:10 DS:2Mhz_Power:GAUGE:120:-40:10 DS:3Mhz_Power:GAUGE:120:-50:10 DS:4Mhz_Power:GAUGE:120:-40:10 DS:5Mhz_Power:GAUGE:120:-50:10 DS:6Mhz_Power:GAUGE:120:-40:10 DS:7Mhz_Power:GAUGE:120:-50:10 DS:8Mhz_Power:GAUGE:120:-40:10 DS:9Mhz_Power:GAUGE:120:-50:10 DS:10Mhz_Power:GAUGE:120:-40:10 DS:11Mhz_Power:GAUGE:120:-50:10 DS:12Mhz_Power:GAUGE:120:-40:10 DS:13Mhz_Power:GAUGE:120:-50:10 DS:14Mhz_Power:GAUGE:120:-40:10 DS:15Mhz_Power:GAUGE:120:-50:10 DS:16Mhz_Power:GAUGE:120:-40:10 DS:17Mhz_Power:GAUGE:120:-50:10 DS:18Mhz_Power:GAUGE:120:-40:10 DS:19Mhz_Power:GAUGE:120:-50:10 DS:20Mhz_Power:GAUGE:120:-40:10 DS:21Mhz_Power:GAUGE:120:-50:10 DS:22Mhz_Power:GAUGE:120:-40:10 DS:23Mhz_Power:GAUGE:120:-50:10 DS:24Mhz_Power:GAUGE:120:-40:10 DS:25Mhz_Power:GAUGE:120:-50:10 DS:26Mhz_Power:GAUGE:120:-40:10 DS:27Mhz_Power:GAUGE:120:-50:10 DS:28Mhz_Power:GAUGE:120:-40:10 DS:29Mhz_Power:GAUGE:120:-50:10 DS:30Mhz_Power:GAUGE:120:-40:10 RRA:AVERAGE:0.5:1:864000 RRA:AVERAGE:0.5:60:129600 RRA:AVERAGE:0.5:3600:13392 RRA:AVERAGE:0.5:86400:3660

I have still got my csv files and want to reload it into my rrd database

HF Heat map monitoring System.

Link on local network http://localhost/hf_noise/images

link to live system

Here is  a screenshot of the monitoring page and the green button

 can be used to select the frequency band of interest

Single view

Here is a view of the HF spectrum from 1Mhz to 30Mhz (activity can now be seen for the day)

Here is a view of the heat map that was selected

If you click on the image the the image will zoomed to maximum
Enlarged View

Here is a screenshot of the enlarged view.

So here is an example of the utility that generate the CSV file
Noise Recording

rtl_power -f 24M:1.7G:1M -g 50 -i 20m -1 noise-unmodded.csv

Here is the instillation instruction


Source code avalibe from

Alt text
Instillation Instructions

#Create user hfnoise

sudo adduser hfnoise

sudo usermod -aG sudo hfnoise

#change to hfnoise user with the following command. (dont try to install with other users)

su - hfnoise

#enter your new password

sudo apt-get update

#If you get this error below do the following

#** (appstreamcli:2761): CRITICAL **: Error while moving old database out of the way. AppStream cache update failed.

#then run this command and try again sudo chmod -R a+rX,u+w /var/cache/app-info/xapian/default

#now lets upgrade and get some coffie :-)

sudo upgrade

#We now need to install git to download the noise monitoring application

sudo apt-get install git

sudo apt install cmake

sudo apt-get install libusb-1.0-0-dev

sudo apt install python-setuptools

sudo easy_install pip

sudo pip install image


#for ubuntu 17.10 do the following.


sudo dpkg -i ./imageinfo_0.04-0ubuntu11_amd64.deb

# for Ubuntu 16.04 do the following


sudo dpkg -i ./imageinfo_0.04-0ubuntu10_amd64.deb


#git clone git://

#Please make sure you use this repository as the osmond one dont support direct conversion mode

git clone

cd rtl-sdr/

mkdir build

cd build

cmake ../


sudo make install

sudo ldconfig


sudo vi /etc/modprobe.d/no-rtl.conf

#add the following blacklist dvb_usb_rtl28xxu

blacklist rtl2832

blacklist rtl2830


#we now need to install an application that will allow us to reset the USB port where the rtl dongle is installed if it locks up for some reason (this has append when there is lightning in the aria.So what i do is motor if the csv file get updated if not I reset the usb port with this utility.


git clone

cd usbreset

#lets compile the application

cc usbreset.c -o usbreset

#we now need to establish witch usb port is your rtl dongle installed.

sudo lsusb

#we now need to edit the shell script that monitor the csv file update with your rtl usb port details.

#now look for the device with this name "Realtek Semiconductor Corp. RTL2838 DVB-T" in my case it was "Bus 003 Device 004" to be like E.g sudo /home/hfnoise/usbreset/usbreset /dev/bus/usb/003/004


git clone

cd hf_noise

cd sh

vi or use your editor and

change the line that looks like this "vi /home/anton/Downloads/usbreset/usbreset /dev/bus/usb/"

002/005" with your detail

#pull the noise monitoring system from github

git clone

#install Apache2 server

sudo apt-get install apache2

sudo systemctl start apache2.service

sudo systemctl enable apache2.service

sudo apt install php7.1 libapache2-mod-php7.1

sudo a2enmod php7.1

sudo systemctl restart apache2

cd /var/www/html

sudo mkdir hf_noise

sudo mkdir hf_noise/graph

sudo mkdir hf_noise/images

cd hf_noise/graph

sudo cp -r /home/hfnoise/hf_noise/*.php ./
sudo cp -r /home/hfnoise/hf_noise/*.html ./
sudo cp -r /home/hfnoise/hf_noise/*.png ./
cd /var/www/html/hf_noise/images
sudo cp -r /home/hfnoise/hf_noise/image/*.php ./

sudo cp -r /home/hfnoise/hf_noise/image/*.html ./

sudo cp -r /home/hfnoise/hf_noise/image/*.jpg ./

sudo cp -r  /home/hfnoise/hf_noise/image/thumb ./

#now test if hfnoise webserver work.

firefox http://localhost/hf_noise

#you should see the index page with no pictures.

#We now need to install the heatmap application.

#lets go to home directory and install heatmap


#got hf_noise directory and install heatmap by git from github

cd hf_noise

#Get the heatmap python progrm from github

git clone

cd /home/hfnoise/hf_noise/rtl-sdr-misc/heatmap

#give the application execution writes

chmod 776 *.py

#Now we need to install the perl librareries

#CPAN, the Comprehensive Perl Archive Network, is the primary source for #publishing and fetching the latest modules


sudo apt-get install perl build-essential curl

sudo apt-get install rrdtool

sudo apt-get install librrds-perl

cd /usr/local/bin

sudo wget

sudo chmod +x cpanm


sudo cpanm --self-upgrade --sudo

#sudo apt-get install cpanminus

sudo cpanm Text::Trim

sudo cpanm Text::CSV

sudo cpanm Date::Manip

sudo cpanm Text::Trim

# mite be only trim

sudo cpanm RRD::Simple


cd hf_noise

cd sh

#run then script to generate rrd db

chmod 776


#Ok now connect your HF dongel to your laptop usb port and connect to an antenna.

#Ok now everything should be ready.

#we need to enable the scripts in the crontab (scheduler)

#run the script to setup the scheduler

sudo python ./

#If you want to see how the crontab was setup you can check with this command

sudo crontab -e

#Below is the what you should see

0,5,10,15,20,25,30,35,40,45,50,55 * * * * /home/hfnoise/hf_noise/sh/ 0,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,58 * * * * /home/hfnoise/hf_noise/sh/ 1,6,11,16,21,26,31,36,41,46,51,56 * * * * /home/hfnoise/hf_noise

#save file and now and we are now done.

#The images and history file should now be automatically being created every 5 minutes.

#Make sure you have along wire antenna connected to your HF rtl dongle to hf noise recordings.


#How can I check that data is collected.

#run the command

ls -lrt /home/hfnoise/hf_noise

#you should see somthing lyk this

-rw-r--r-- 1 root    root          0 Nov  8 19:06 hf_monitoring_08-11-2017.cvs

-rw-r--r-- 1 root    root          0 Nov  8 19:06 hf_monitoring_graph_08-11-2017.cvs

You should also see graph images in you browser.

firefox http://localhost/hf_noise/graph/1Mhz_Power.php

File upload to Master Analytics site will be available when it goes alive.

This is how you will setup a Automated NOAA Weather satellite imaging system.
This system is available from Giga Technology
Here is the link to a live system in South Africa
Here is a sample image
This board is now complete and is available from Giga Technology.
This repository will have all the files for the PCB that fits on a Raspberry Pi witch will have a 7 stage low pass filter for the VHF 2m band. (About 60db down for first harmonic)

This board is to be used with the rpitx utility to alow you to transmit on the 2m VHF band. This board will have 7 stage lowpass filter. Here is the filter design details. Alt text Filter similator Diagram Alt text The PCB files is Kicad file format. The circuit diagram

Alt text PCB layout diagram during design Alt text

Changed Connectors transistor and regulator Alt text

3D view of Board

This Board is now avalible from Giga Technology
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