Een vriend stuurde mij op een chatkanaal de volgende pagina toe:

http://www.kempelektroniks.com/General/Tweaks.aspx

Ik dacht eerst bij een Nederlandstalige parodie op een doorgeschoten hifispecialist te zijn gekomen, maar naar enig gescroll kwam ik erachter dat alles op deze site gemeend was. Genoeg andere Nederlandse sites met “speciale”, enorm dure kabels welke, ondanks keiharde tegenargumenten uit de natuurkunde een enorme geluidsverbetering zouden moeten brengen.

Ik heb altijd vermaak gehad aan de hilarische, pretentieuze claims op vele audiofiele websites en aan hoe men terugkrabbelt als er door sceptici een zgn. dubbelblinde test van de gepromote produkten wordt voorgesteld.De site van Kemp Elektroniks, echter, presenteert een aantal voor mij nieuwe audiofiele “uitvindingen” waarbij ik geestelijk heen en weer werd getrokken tussen schaterlachen en alle vertrouwen in de mensheid verliezen.

Let op: Alleen verder lezen als je dit geestelijk aankan! Read more »

Just some venting,

Why on earth is every interesting technical discussion forum on Yahoo Groups? I absolutely loathe its design. When requesting the main forum it presents you with unthreaded, ungrouped messages by date. To group messages by thread you have to click a link, and even then you have to click each message separately just to view it. It’s 2012 damnit, stupid threaded message boards should be a thing of the past! Read more »

English summary below

Via Ebay wat eitjes van Triops cancriformis besteld, de europese ondersoort. Ik heb eerder deze soort proberen te kweken maar de eitjes kwamen niet uit. Nu dus een nieuwe poging en er is leven in mijn kweekbakje. Read more »

My online geiger counter which I described earlier has been offline for some time. During that time I experimented with a standalone Arduino with the goal of making a dedicated board for the setup. I have now completed the board shown in the picture below.

In the picture you can see the HV generator on the top of the board, on the lower left the Arduino standalone parts along with a MAX232 as a level converter for easy serial hookup and on the right two tubes connected in parallel, a SI-29BG (beta and gamma) and a SI-12B for added alpha sensivity. Also shown are the USB>Serial adapter and a separate USB connector to provide 5V to the board. Read more »

(picture: “Geiger Tube” by “dh” on Flickr, showing Russian SBM-20 hard beta and gamma GM tube)

On the internet there lots of DIY people showing off their homebuilt Geiger counter circuits, complete with microprocessors and LCD’s calculating and displaying count rates and often the dose rate in microsieverts/roentgen per hour.

The last thing surely makes a project look more impressive with the floating point number with a weird unit that most people are unfamiliar with. It’s not a big deal with DIY setups but there are lots of mentions of sending projects to Japan to help people over there “measure” contamination. Read more »

With the developing nuclear disaster in Japan, I discovered that there is lots of money being made selling geiger counters. Prices of geiger counters on Ebay and various other places seem to have tripled instantly.

Well, you could say that’s the free market in action. But it wouldn’t surprise me if prices are driven up by people not actually needing geiger counters but buying them anyway out of fear while they are not likely to experience any effects of the disaster.

Today I saw something much worse, some German on Ebay trying to sell a “geiger counter” which actually is a high range survey meter, a CDV715 according to the picture. Read more »

I own a CDV-700 geiger counter of which the tube stopped working. It turns out that replacement tubes are both hard to find and expensive. The simplest option is to buy the LND 720 which basically is a drop-in replacement that should cost about $100.

It’s also possible to use cheaper, easier to find tubes with the CDV-700.  I found the following post from radio amateur K0FF on the “Geiger Counter Enthousiasts”  group on Yahoo groups. It describes a simple circuit to adapt tubes of varying voltage to the CDV-700. I built one, and it works! Read more »

I have always had an above average interest in radioactivity.  It’s a subject with political, sociological and scientific aspects. I have been mostly interested in the scientific part, but I also closely follow any news and other developments. With the earthquake in Japan and the following nuclear disaster the discussion about nuclear energy has  been fired up after being quite silent for years. In the Netherlands there was talk about building a new reactor next to the existing plant in Borssele. Well, I guess it will be a bit harder now to get support for this plan…

To be honest, watching the developments with the damaged reactors in Japan got me thinking again. Is nuclear energy a proper way of generating electricity? Sure,  for the immediate surroundings it is very clean. There are virtually no CO2 emissions and with proper shielding and maintenance you’ll need some pretty advanced equipment to measure any radioactivity coming from a reactor. Still, uranium mining is not very nice for the environment and there is no clear solution for storage of waste. And, if a reactor malfunctions there is the possibility of widespread contamination as currently seen in Japan. So, while I am not against nuclear energy my support for it has weakened somewhat.

Anyway, enough rambling, how to monitor radiation with your computer!

Update 18/4: Guess I am not the only one doing some monitoring: http://radgoes.blogspot.com

Read more »

Momenteel hou ik mij nog steeds bezig met het houden en kweken van Triops. Ik heb de afgelopen maanden wat generaties opgekweekt en weer zien sterven en ik heb eitjes weten af te scheiden om voor toekomstige generaties te kunnen zorgen.

Op het moment ben ik wat aan het experimenteren om een bak met Triops wat represenatiever te maken met de dingen die je normaliter in aquaria voor vissen ziet. Ik heb grind gebruikt om waterplanten goed te kunnen laten wortelen, en een stuk kienhout op de bodem gelegd. Read more »

This article will try to explain how to monitor and graph temperatures remotely using Dallas Semiconductor DS18xx sensors, SNMP and Cacti. DS18xx sensors are relatively cheap, accurate and multiple sensors can be connected to a single bus.

This guide is based on Ubuntu, so YMMV on other Linux/Unix based systems and may need modification to work properly.

Read more »