I’ve been playing around with a homebrew weather station again, I dusted off the code I’d had running on a spare Raspberry Pi and added a few features to it. It’s now logging temperature, humidity and air pressure. I plan to add some more external sensors as soon as the parts arrive from eBay.

The graphs below are live data (for as long as I keep the station running)

The code will be on github shortly.

X-Ray Monday

The X-Ray scanners  I use to produce the images for this series of posts are mainly used for producing 3-D data, they are Micro-Tomography scanners, so they don’t produce a large field of view, but thy do provide high resolution.

This means images like the one below can be a little hard to decipher if you don’t know what’s been imaged.


Continue reading X-Ray Monday

VHF Radio Coverage

I’ve just discovered a nice tool for plotting radio transmission coverage. Here’s where I can expect to get a signal too from my home location.

Where 100 watts of 145 MHz RF will get, from my home QTH
Where 100 watts of 145 MHz RF will get from my home QTH

Yellow shows 0.50 μV signal level, Green is the 1.58 μV signal level

This seems to match up quite well with contacts I’ve had on the two-meter band, but with less power actually used. I’ll have to play a bit more and see how it says my station will perform on other bands.

The insides of things are beautiful…

…lets see what they look like.
These days I work with X-Ray systems. I’m just finishing up commissioning and testing of the latest one, so I’m using it to image various things.

This is a compact fluorescent lamp. At full size you can see the coils of tungsten wire in the electrodes in the glass spiral, you can also see some tiny droplets of condensed mercury at the end of the spiral. It;s this mercury that’s essential for the operation of the lamp, but is also what makes them (slightly) hazardous if the glass breaks.
Compact Fluorescent Lamp