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advocacy

amateur-radio

Echolink on Android

How to use Echolink on Android, a robust Echolink option for those times you forgot to bring your radio.

WSJT-X on Ubuntu

How to operate JT65/JT9/FT8/WSPR powerful weak-signal modes on Linux. Operating strategies described.

Loading WSPR raw audio data

WSPR raw data in the form of audio files is highly useful for radio science analysis. Here’s how to load these files into Python.

Proposed HF TOA experiments

A group is proposing experiments to determine limits on HF skywave direction finding. Let’s put the SDR-IQ to some experimental use!

android

aurora

benchmarking

bibliography

bios

bluetooth

Bluetooth Sound on Linux

Quick setup Bluetooth sound (speaker) on Linux PCs and embedded single-board computers, including the Raspberry Pi.

Bluetooth speaker with FM radio

I consider having an FM radio in a Bluetooth speaker essential, as well as having SD card and 3.5mm input. The Simpowel V8 fulfills these needs for under $40.

SoundBot Bluetooth headphones

Detailed review of Soundbot SB240 and SB220 Bluetooth headphones–noting some problems with modern Bluetooth source devices.

bsd

c-lang

cad

Free 2-D CAD overview

Comparison of AutoCad drop-in compatible popular free 2-D CAD packages DraftSight, QCAD and LibreCAD.

cmake

commentary

Quote of the Day

Quote from Aristotle on how to realize the Earth is a sphere, in ancient times.

computer-vision

crypto

Kraken minimum trade size

Cryptocurrency exchanges typically have minimum trade sizes to avoid excessive transaction volume slowing down the system.

cybersec

digital-rights

docker

ebook

engineering-education

ffmpeg

fortran

Fortran build systems

Brief survey of Fortran build systems, settling on CMake as most powerful vs. ease of use.

Fortran gdb/gdb-ia Debugging

How to debug Fortran code for one accustomed to Matlab/Python debugging. Cheat sheet for gdb or Intel gdb-ia debuggers.

git

Travis CI examples

Quick examples of Travis-CI – a system that runs your self-test on each git push. It can save you from hard to find bugs later.

Completely undo errant git remote push

For any Git remote repo (e.g. Github/Gitlab), you can undo (delete from git history) the last or previous pushes to eliminate huge/numerous/wrong files pushed.

https

idl-gdl

image-processing

Convert PDF to SVG

How to convert PDF to SVG vector graphics for high resolution diagram on a webpage without download.

infosec

julia

labview

latex

How to use LaTeX directives

LaTeX directives allow automatic specification of which compiler to use (e.g. XeTeX) and which document is “root”. Here’s how.

Overleaf v1 with GitHub / GitLab

How to use GitHub / GitLab with Overleaf v1. With Git I could recover a corrupted document from Overleaf post facto. Using Git a priori stops such corruption.

Convert RIS to Bibtex

How to convert RIS citations to .bib BibTeX/LaTeX format quickly. Also how to create PDF from .bib

libreoffice

linux

When is sudo needed?

sudo is not often needed on Linux/Unix computers. In fact, sudo can break installs or goof up the operating system. Here are some guidelines on sudo use.

Force apt to IPv4

Sometimes a remote host or your ISP is temporarily misconfigured with regard to IPv6. You can force apt to use IPv4 as follows.

machine-learning

maker

matlab

AIDA tools

Work with AIDA Tools auroral tomography in modern Matlab versions

Compile Matlab code to run on any PC

How to compile Matlab code to an executable, so that Matlab isn’t needed to run the .m file. The free Matlab Compiler Runtime is needed on the non-Matlab PC.

open-cytometry

open-data

Zenodo data upload speed

My uploads of large datasets to Zenodo (or other such sites) are often restricted by upload speed.

CD-R is NOT for archival purposes

As CD-R writers become commoditized, some people don’t realize CD-R have a short lifetime, and even standard CD’s don’t live forever.

open-source

optics

people-who-scale

People Who Scale

Blog series on people who scale in business and life, helping pick the most robust and reliable business partners.

perl

piradar

python

Mayavi 4.6 easy install

How to easily install QT5-based Mayavi 4.6, a powerful, easy to use 3-D plotting package based on VTK8.

flake8 PEP8 quick start

PEP8 code style greatly helps code readability. flake8 catches unexecuted syntax errors otherwise missed by CI.

Matplotlib date/time examples

Matplotlib can make many types of plots with a time axis. However, sometimes it takes an additional command or two to make the date/time axis work right in ...

Numpy N-D rot90 flip

Numpy 1.12 adds pathlib support throughout, and upgrades rot90 and flip to handle N-D arrays–big improvement.

How to install VisPy OpenGL for Python

VisPy uses PyOpenGL for beautiful, fast 3-D and 2-D plotting from Python and Numpy arrays. Here’s an easy way to setup VisPy–you don’t need a discrete GPU.

How to install Glumpy OpenGL for Python

Glumpy uses PyOpenGL for beautiful, fast 3-D and 2-D plotting from Python and Numpy arrays. Here’s an easy way to setup Glumpy–you don’t need a discrete GPU.

radar

research

Mathematics of Auroral Viewing

When you observe aurora borealis or aurora australis, what you see is a line integral of the optically thin aurora. Here’s the math.

ride-sharing

ridesharing

Ridesharing walk to pickup

Uber Pool Express in Boston require walk to easier pickup locations. Lyft in Washington, D.C. suggests better pickup points.

right-to-repair

ruby

scientific-cameras

scilab

shell

software-defined-radio

RTL2832 ADS-B decoder

How to decode/log/display ADS-B aircraft transponder data with $20 RTL2832 USB receiver & Raspberry Pi.

ssh

travel

No more Amtrak gate dragons

Amtrak is removing gate ticket checks from major stations, and instead scanning tickets once aboard at the station.

Amtrak Dunkin’ Donuts coffee

Dunkin’ Donuts coffee first came to Amtrak Acela in April 2017, and has now expanded to Northeast Regional trains from Richmond, VA to Boston, MA.

virtual-machine

virtual-reality

vnc

wear-os

Wear OS autonomous via Wifi/LTE

How to use Wear OS smartwatches semi-autonomously with non-Android, non-iOS devices. For example Wear OS with BB10 or Windows Mobile device.

wifi

window

windows

Cygwin on Windows 10

Cygwin compliments Windows Subsystem for Linux capabilities. A key Cygwin advantage over WSL is the ability to run as a service.

Using Python3 on ReactOS

At the time of this writing, Python 3.4 is the newest version that can be used with ReactOS, since newer Python version require sufficient Windows NT ≥ 6.0, ...

ImageJ-Win64 won’t start

If ImageJ won’t start on Windows, try the one-time command ImageJ-Win64 –cp jars/javac.jar and thereafter the ImageJ icon should work normally.

wine

WINE serial port links

WINE 2.8 brought a new better way to handle serial port links from Linux to Windows programs.

wireless

Google Fi technical aspects

Google Fi uses three LTE carriers plus VPN WiFi. Here are some practical details on how the Google Fi aggregating MVNO works.

NEXTEL is back?

A trademark-holding company has claimed the “abandoned” Nextel trademark and has licensed it. What’s going on?

USA 2G cellular shutdown

Possible 2G GSM shutdown impacts vis cheap replacement 4G modems. US 2G shutdown targeted for 2019.

How Paging Coasters work

Technical explanation of paging coasters in the 27 MHz and UHF bands, including antennas and interference.

Nextel acquires 900 MHz SMR spectrum

Nextel spent a quarter billion buying 900 MHz Arch Wireless spectrum. FCC authorized 5 MHz more of 800 MHz for CMRS, when will it be our turn to be acquired?

Wireless WAN in the Midwest

Wireless data or wireless WAN (WWAN) is growing rapidly. Going beyond two-way paging and package tracking to email for business.