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Showing posts from July, 2017

Olde Skool Antenna Design with NEC2 on OpenBSD

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 files.  I learned

Cube Satellites

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. This opportunity has been used by many universities and radio amateur groups: A few months ago, the American University in Sharjah also launched a cubesat called NAYIF-1: .  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 real-time: http://da