Skip to main content

Let There Be Light

I made a ceiling light fixture for my workshop (it is supposed to be my garage) from scrap wood.  Since LED lights do not get hot, one can do that without danger of burning the house down, but it would be a good idea to incorporate a 250 mA polyfuse in there for peace of mind.


The light of my life.

To hide the ceiling house wires and chocolate block connector, I made a big hole in one block with a hole saw and glued it to another block.  The vertical stick is mortised into the ceiling block - rubbed some wax on it all and there we have a little Tinkertoy Chandelier.  I used bees wax, but good old boot polish will work as well and it comes in multiple shades.

Cantilever Desk Lamp

BTW, the easy/lazy way to make a rectangular mortise hole, is with a drill and a jigsaw.   You just slowly grind the wood away with the saw blade till you have a perfect fit.  A hammer and chisel does not work well on soft wood, no matter how sharp the chisel, while a jigsaw will happily chew up anything!

I made two of the ceiling lights and one desk lamp.  The lamp fixture is invisibly fastened to the end of the stick with a little screw and epoxy glue.  The counterweight more or less balances it, which makes it easier to adjust and stay in place.

Now I had enough of sandpaper and lamps for a while - if I can just stop sneezing!

La voila!



Popular posts from this blog

Parasitic Quadrifilar Helical Antenna

This article was reprinted in OSCAR News, March 2018: If you want to receive Satellite Weather Pictures , then you need a decent antenna, otherwise you will receive more noise than picture. For polar orbit satellites, one needs an antenna with a mushroom shaped radiation pattern .  It needs to have strong gain towards the horizon where the satellites are distant, less gain upwards where they are close and as little as possible downwards, which would be wasted and a source of noise.  Most satellites are spin stabilized and therefore the antenna also needs circular polarization, otherwise the received signal will flutter as the antennas rotate through nulls. The helical antenna, first proposed by Kraus in 1948, is the natural solution to circular polarized satellite communications.  It is a simple twisted wire - there seems to be nothing to it.  Various papers have been published on helix antennas, so the operation is pretty well understood. Therefore,

Weather Satellite Turnstile Antennas for the 2 meter Band

NEC2, 2 m band, 146 MHz, Yagi Turnstile Simulation and Build This article describes a Turnstile Antenna for the 2 meter band, 146 MHz amateur satcom, 137 MHz NOAA and Russian Meteor weather satellites.  Weather satellite reception is described here .  A quadrifilar helical antenna is described here .   Engineering, is the art of making what you need,  from what you can get. Radiation Pattern of the Three Element Yagi-Uda Antenna Once one combine and cross two Yagis, the pattern becomes distinctly twisted. The right hand polarization actually becomes visible in the radiation pattern plot, which I found really cool. Radiation Pattern of Six Element Turnstile Antenna Only a true RF Geek can appreciate the twisted invisible inner beauty of a herring bone antenna... Six Element Turnstile Antenna Essentially, it is three crosses on a stick.  The driven elements are broken in the middle at the drive points.  The other elements can go straight throug

Patch Antenna Design with NEC2

The older free Numerical Electromagnetic Code version 2 (NEC2) from Lawrence Livermore Lab assumes an air dielectric.  This makes it hard (but not impossible) for a radio amateur to experiment with Printed Circuit Board Patch antennas and micro strip lines. Air Spaced Patch Antenna Radiation Pattern You could use the free ASAP simulation program , which handles thin dielectrics, you could shell out a few hundred Dollars for a copy of NEC4 , You could buy GEMACS if you live in the USA, or you could add distributed capacitors to a NEC2 model with LD cards (hook up one capacitor in the middle of each element.), but that is far too much money/trouble for most. More information on driving an array antenna can be found here: l Air Dielectric Patch   The obvious lazy solution is to accept the limitation and make an air dielectric patch antenna. An advantage of using air dielectric, is that the antenn