Aeronetworks sro - Airborne Linux

I am an ex Army Signals officer and also built military HF radio equipment for a period of about ten years - man pack, ground and airborne, so when I saw the new BitX40 radio kit, I just had to get a couple to play with. These kits are made in India, are good quality surface mount, built up tested and aligned.  For the princely sum of $59, one can get two or three and have fun: http://www.hfsigs.com/ Bread and Circuses Here is my breadboard setup.  Yup, it is a real olde skool bread cutting board.  Wood is a good insulator and some blue ticky-tacky keeps things down: BitX40 7 MHz SSB HF Radio The BitX40 is an analogue radio, with a digital synthesizer tuner - so it is a throwback to some time before the dinosaurs, circa 1985 - nice and simple. The default setup is for the 40 meter band, but one can tune it for any HF band, by using switches and coils.  They are so cheap, one could get multiple radios and configure each for a different band of inter...

I had a look at radio amateur Slow Scan TV and noticed that it is analogue, so I wondered whether I can create a digital version using gstreamer. Here is an example script that will play one video frame every ten seconds.  This could very well form the basis for a digital SSTV system. The first part of the script are commented tests that show how I worked my way up to the super slow method that uses the videorate plugin to drop most of the frames. Note that due to the long time between SSTV frames, everything will always be different, so motion jpeg will likely work better than h.264 compression. #! /bin/bash echo Slow Scan TV example with a laptop PC camera and gstreamer # Install all the plugins including v4l2src: # dnf install gst*plugin* # Play the laptop PC camera the simplest possible way using the system defaults: # gst-launch-0.10 v4l2src device=/dev/video0 ! autovideosink # Play the camera and scale it smaller at 30 frames per second # gst-launch-0.10 v4l2src dev...

The Numerical Electromagnetics Code (NEC) is a powerful and efficient program for the analysis of the electromagnetic properties of antennas and other objects. It is a Method of Moments type of successive approximation program and dates back to the time of the dinosaurs.  In theory,  practise and theory are the same,  but in practice not. To measure, is to know! NEC was developed on a CDC 7700 in the mid 1970s to early 80s at Lawrence Livermore by Burke and Poggio for the US Navy and it was paid for by the friendly US tax payers - free for use by anyone now. Dipole Antenna Example CDC - Control Data Corporation, became Computing Devices Canada, which became General Dynamics Canada - I worked there through all the name changes - but you don't need to go hunt in a museum for a CDC 7700 to run NEC - an Intel PC will do.   The NEC documentation amusingly still refers to stacks of punch cards, but these have been replaced with simple text fi...

For a few years, it has been possible to launch tiny educational satellites - for free - to fill up some of the unused payload space on big rockets.  http://www.asc-csa.gc.ca/eng/satellites/cubesat/default.asp This opportunity has been used by many universities and radio amateur groups: http://www.asc-csa.gc.ca/eng/sciences/canadian-cubesat-project.asp A few months ago, the American University in Sharjah also launched a cubesat called NAYIF-1: http://www.arrl.org/news/nayif-1-cubesat-to-have-funcube-transponder .  It has been passing overhead many times and I was a bit miffed that I did not know about it before the launch, had no idea how to connect to it and to my knowledge, the radio amateur law in the UAE did not allow foreigners to operate.  The NAYIF-1 satellite is a CubeSat-5, which is a little different from the CubeSat-1.   Here is the AmSat data warehouse for the NAYIF-1 (EO-88), which shows all the pertinent information on the satellite in re...

A hobby project needs to be simple, so that I can sit down, stare at the circuit for a few seconds and carry on without having to read a manual and consult six data sheets, because then it feels like work.  Consequently, I found that thermionic valves make ideal hobby toys, since the circuitry necessarily has to be simple.  One can use a double handful of ICs and transistors in a hair brained design, but with tubes, two or three are the practical limit and this forces one to think carefully about what one wants to do and keep it elegant. Here is my olde skool guitar amplifier: http://www.aeronetworks.ca/2015/02/cool-amplifier.html It works a treat. There is nothing quite like the mystical glow of a Nixie Tube.  The Nixie is a special kind of neon lamp.  The Neon glows in space surrounding the almost invisibly thin cathode wires.  The wire itself is cold - it is the gas around it that glows and the glowing area is much wider than the wires. A Nixi...

It is a big Microsoft security waste of time, again and again... The quality of computer software bears no relationship to its price.   In fact, the best software tends to be free. I usually tell friends and family that I don't do Windows .  They then assume that I am one of those weird Mac users.  They are correct of course - I am weird and I use a Mac too - amongst many other types of machines, including those most annoying Windows machines... Long ago, I used to tell people that they can use Microsoft software: It is rather buggy, but it is cheap.   Nowadays however, it is still buggy and very expensive, especially so when you factor in the maintenance cost. If you are one of those weird people who insists on wasting money on expensive bad quality software , then you should immediately read this: https://www.theregister.co.uk/2017/05/13/wannacrypt_ransomware_worm/ and this: https://blogs.technet.microsoft.com/msrc/2017/05/12/custom...

Engineers will recognize that this post is about stock trading, others may wonder what is a stochastic system . Market price data is a time series of mostly random data, a stochastic system .  So a Day Trader is a Stochastic Systems Analyst - now doesn't that sound fancy! Investopedia Simulator   The one thing I learned over the years is that if you want to make money from trading stocks or futures, then you need to have a simple and well defined system, with easy to calculate entry and exit criteria, otherwise you will eventually lose your shirt. As the late Douglas Adams, the famous galactic economist of Bistromatics fame said:    When it is infinitely improbable that something will ever happen,  it will happen almost immediately. Price data is mostly random.  In retrospect it seems to follow a trend and engineers and computer programmers get duped into thinking that they can easily devise a system to do automated trading based on historical ...