Titanium Tea Strainer...

If you're a tea drinker, as I am, I highly recommend these strainers (under $15).

Here's to You, Mr. Jefferson...

Awesome, with Tea Party snaps:

Building a Radio, from Scratch...

Ran across this fascinating story from World War II, about British prisoners in a Japanese POW camp who built a working radio receiver from scratch. A taste:

I should come back to the capacitors on that, because we had to insulate the layers of those which we did by putting a layer of newspaper (a few people had newspaper and various things, for other reasons than newspaper of course, but then we had no other toilet requisites in the party) and by soaking this in some coconut oil we could insulate each layer after we wound it, and with a piece of this bee wire - we had something like fifty feet of it - wound round this part of the fish plate, we made a fairly good choke coil. And then a bigger capacitor, which was no trouble, having had success with the small one, to just wrap as much tin foil as we could round another sheet of newspaper which finished up about 18 inches long by about three quarters of an inch in diameter. We didn't even try to measure the capacitance of it, because we couldn't do anything about it anyway, except put more wire on. And that in effect was a fairly good rectifier, a very dangerous one because we had the 110 all right but we had a bit over that by the time we had rectified it, and we don't know because we had no means of measuring it.

Finally, the valve; we joined the valve by winding the clean little bee wire around it and then plugging it with any insulating material we could get to make it stick, - no valve holder, of course. So eventually we produced a receiver of sorts, except it wouldn't oscillate. We tried building more, another choke coil, and this went on for ages; there was no possibility we could get this valve to oscillate. I think it's recommended according to a friend of mine who had an amateur license, he thought that about 120 volts was the best we could get and there was no way we could get that by trying to smooth this any more. So the only avenue open was to bribe one Chinese working at the power station who was very much our way, and of course in those days was a nationalist Chinese.

For my readers unfamiliar with antique British English, a “valve” is what Americans would have called a “vacuum tube”, or just “tube”. For my younger readers, a vacuum tube is a device used for electronic amplification and rectification before the advent of semiconductor transistors and diodes.

Now I have built some electronic devices (including a radio receiver) from bits and pieces. My dad helped me build an old-fashioned crystal radio this way. But we had some purchased components (the headphone, the rectifying crystal, wire, etc.), easy access to things like waxed paper and aluminum foil, and some basic test equipment. These POWs not only had extremely limited materials at hand (though they were uninhibited about bribes, blackmail, and theft), they had no test equipment and no reference material. For instance, when they designed a capacitor, they had to either remember or re-invent the basic formulae describing capacitance!

One side-effect of our rapidly advancing technology base is that there are now relatively few people who understand the basics and fundamentals. In electrical engineering, for example, most time is necessarily spent on advanced integrated systems, and very little on the fundamentals of components. After all, in modern design work that newly minted engineers are likely to do, there's little use for the primitive components such as those the POWs made. On the other hand, back then electrical engineers generally were directly involved in the design of such components – so that knowledge would have been much more widespread in the engineering community...