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GPS Track Profile Analysis using Perl
In this post I show a small example on how one can easily evaluate GPX track files using Perl and Gnuplot. The idea in brief: Read in GPX track infile.gpx and extract the velocity distribution. In a first approximation I have fitted gaussian distributions… …
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Repair the Power Supply of an Apple TimeCapsule
In the first generation of Time Capsules there was a quality problem with the capacitors in the switching power supply: a lot of them broke due to heat problems after about 17 months There is an excellent instruction on how to repair the device. Nevertheless the information which capacitors to use is missing. In this post I present a short instruction including more detailled information on the capacitors. …
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Network Properties Simulation Using qdisc
If you ever want to simulate bad transmission conditions (packet loss, latency, bandwidth, …) in a network: there is a module built-in to the linux kernel named qdisc. More information can be found on tldp.org. …
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Thoughts on Accu Cells
Recently, new technologies in Accu Cells have emerged, such as the widely known A123 LiPo cells. In particular, for outdoor qrp activities it is suggested to use these cells due to their superior capacity/weight ratio. However, these cells are more difficult to handle: charger, load balancing during loading cycle, low voltage damages, form factor and voltage of the single cells prevent usage in other common devices. Furthermore, the Ready-to-Use NiMh cells, i.e. Eneloop, have overcome the issues with excessive self-discharge. …
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Creating an Envelope from Commandline Using LaTeX
This small piece of code will create an envelope from commandline… …
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Make an Image with Email Address
This is a small piece of code to create an image from your Email address: …
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Scan PDF from Commandline
In the following I show a small piece of code to scan PDF files from commandline: …
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Using SSH as VPN
One of the not so commonly known features of SSH is: you may use it for a poor man’s VPN. …
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Installing the AirPort Utility 5.6 in OSX Mountain Lion
Some of the older AirPort devices will not work with current versions of the AirPort Utility and old versions cannot be installed on OSX Mountain Lion (yet). The old version can be installed manually in parallel to the new version: …
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QRP Propagation Simulation: One Day on All Ham Bands
Below a series of images for the band conditions today using the parameters of my QRP station. …