My Metal Detectors

Here's something about me that may not be known to all: I invented two new genres (that is, families) of metal detectors. See, as an example, Detector Types. Alexander Graham Bell invented IB in 1881, Gerhard Fischar invented BFO in 1925, and Claus Colani invented PI in 1961. In 2004, I invented BB and CCO (well publicised at the time). I also revolutionised IB, by stripping out the analogue electronics. BB detectors are potentially very simple. A three-component design (plus search coils) out-performs most BFO designs -- and CCO detectors match the performance of IB, yet don't require the critical set-up. There are examples of both on this blog. OBSERVATION: While "new" ideas may only be new until someone proves otherwise, my invention of BB and CCO has been very public and has remained unchallenged for six years. Besides, the ideas were too good not to have been known if they had existed before. The image shows one of my metal detector "covers".

Cobalt-60

My hobby is or was electronic design. About five years ago, I wanted to test a p-n junction as a detector of radioactivity. For this, I needed a radioactive source. This was a problem -- but ultimately I got hold of a section of cobalt pencil (cobalt-60). The cobalt was a beautiful blue, encased in a very heavy lead container. As it happens, my experiments didn't work as planned, and I returned the cobalt-60. OBSERVATION: Cobalt-60 is one of the preferred ingredients for a "dirty bomb". My own piece of pencil could have contaminated more than 100 square kilometres, and I obtained it without any clearance. So I would think that, yes, "radiological attacks constitute a credible threat". At least over here.

POSTSCRIPT: If I did it again, I would try a (call it) c-a junction with a neon tube.

Flashback 1968

Here's a photo of me in 1968, on Tarawa atoll, in the mission. To keep me, my sister, and other youngsters entertained, my mother would give us tasks (such as: "Build a hut") -- then afterwards she would inspect them and grade them. On this day, my hut was undoubtedly the best -- yet I didn't get the highest grade. I protested. My mother explained that she had to give everyone a chance with the best grades. You may click on the photo to enlarge to VGA.

Father's Authority

I attended this Uniting Reformed Church (URC, or VGK) earlier this year. It was Father's Day. A deaconess asked all the fathers to stand (pictured). She told us that we had a divinely ordained authority over our wife and children, and a godly responsibility towards them. OBSERVATION: (I have yet to inform the wife!)

Village Bell-Tower

This is the "bell-tower" of the Uniting Reformed Church (URC, or VGK) in the village of Redelinghuys. I tried to call the Church earlier today, to offer them our organ (see the previous post). But not too surprisingly, they don't have a telephone. So says Telkom. You may click on the photo to enlarge to 200k.

Fugard Theatre

The photo shows the face of central Cape Town's Fugard Theatre, which I visited on Saturday. Built in 1860, this was once the hall of the Congregational Church. But in 1906, the Congregational Church behind it (built in 1830) was demolished. The area had changed from residential to commercial. Judging by the hall, it must have been a beautiful Church. You may click on the photo to enlarge to 250k.

Aurora DRC

The village of Aurora lies some 200km/125mi north of Cape Town. Here's another photo of the Dutch Reformed Church (DRC, or NGK) Aurora -- built in 1908. You may click on it to enlarge to VGA. OBSERVATION: In South Africa, the DRC (as in this case) is often the centrepiece of the village.

Palaeontology

I used to write for the popular electronics press (well, I still do). However, some of my electronics ideas, while I thought they were good, would not sell a million magazines. Here's one that I thought could change the face of palaeontology. Son M. had found a job at the South African Museum, where he needed to clean Permean fossils. These are stone, through and through, and one needs to drill away surrounding rock -- without drilling into the fossil. This is painstaking and time-consuming work. So I designed an extremely sensitive Ohmmeter -- and with this I proved that the resistance within a fossil, and the resistance within the surrounding rock, are two different things. On this principle it should be relatively simple, therefore, to speed up the cleaning process -- if not automate it. The photo shows one of the fossils I experimented with.