A homebrew Single Sideband transmitter

This new article on my Possibly Interesting site is strictly for radio amateurs and other geeks: a photo-essay depicting circuit and construction details of the SSB transmitter I’d built a long time ago. What makes it interesting (other than the nostalgia of vacuum tubes, that is) is the prevalence of improvised, scavenged and military surplus components – necessitated by the paucity of the component supply (and funding) in the Israel of those pre-internet, pre-Startup Nation days.

Homebrew SSB transmitter

Enjoy!

Meet a Mathematical Inventor!

This is Jaen-Antoine Lafay’s Hélice a Calcul, a rather unusual logarithmic slide rule. But Lafay himself, its inventor, was just as unusual, not to say quirky… a fascinating lone innovator waging war on an indifferent world.

Lafay's Hélice a Calcul

To illustrate, here is a section from Lafay’s marketing brochure:

Oh, routine! What wrong do you not do, firstly to your devotees who, to avoid a little effort of adapting to innovative tools and processes, which would render them remarkable service, are unwilling to budge from their old deplorable habits,… and then to these poor Don Quixotes who, in believing they might overcome them, only bruise themselves against your incredible force of inertia? And yet, poor fool that I am, with the present brochure I resume a battle that I should have abandoned, moved again by the illusion that I may end up victorious.

See what I mean? And yet, he was an innovative entrepreneur, and you may enjoy the new article I devote to him on my History of Computing exhibition.

Enjoy!

 

Lieutenant Brenske’s Marsch-Zirkel

In the days before GPS, Google Maps and Waze, people used maps; and to figure how long it would take to get from A to B on a map, you could make excellent use of a Marsch-Zirkel, or march compasses… like the lovely device described in this new article on my History of Computing exhibition.

Lieutenant Brenske's Marsch-Zirkel

Dating back to the late 19th century, this ingenious little tool helps you figure the distance and the time to cover it – with infantry or cavalry.

Take a look!

Mind the footprints!

An important element of everyday product design that is all too often ignored is the footprint of an object.

I mean, look at these two electric kettles, which are very common kitchen appliances. They serve the exact same purpose; they use the exact same technology; they have the same water capacity.

Electric Kettles

But there’s a big difference: the one on the right has a sensible, compact cylindrical form. The one on the left, by Kennedy, flares at top and bottom, so its footprint – the counter-top area it requires – is some 45% grater than for the Graetz kettle beside it. Kitchen counters can never have too much free area; the designers at the Kennedy company have wasted some of that area for no good reason at all, simply to show off their “artistic originality”.

I see this cavalier attitude to footprint in many products, and it always annoys me… why can’t these people think of their users?

 

A Googie Kerosene Heater!

Kerosene heaters are smelly, require much maintenance, and are dangerous if used carelessly; on the other hand they create a lot of heat, are independent of utility feeds, and for us older folks they actually have a nostalgia evoked by the conditioned association of the kerosene smell and the pleasant warmth of years past. Be that as it may, they are seldom seen today, and those that are around are mostly stored for backup in case of winter power outages. They also tend to be bulky and ugly…

So here is one that is neither, a vintage unit sighted at the Jaffa flea market: a perfect compact  sphere, in the mid 20th century style.

Googie Kerosene Heater

Not sure how safe it is – seems it would toll over if bumped – but you gotta love the red color and the nice Googie design!

 

A most unusual slide rule

The Baines slide rule is one of the most unusual ones in my collection, because of the metal contraption on its back that moves all its parts in unison. Here it is:

The Baines hydrological slide rule

This slide rule was designed by a British civil engineer from the Punjab; it is used to calculate water flows and pressure drops in cast iron water pipes.

You can see the full details, and a sample calculation demonstrating the device’s function, in this new article on my history of computing site.

 

 

Russian Roulette!

Clearly marking tool and instrument controls is always a good idea, but it becomes vital where safety is at stake. And if there is one control where safety is definitely at stake, it is the safety catch!

Like this one, on a rechargeable jig saw from Taiwan:

Jigsaw with unmarked safety lock

See the switch clearly marked “Safety Lock”? Very informative… but there is not a hint as to which position is the locked one. There is a picture that may try to indicate this, but it is quite ambiguous.

So – this is really a weird implementation of Russian Roulette. But hey, at least it’s rechargeable…

The ancients had it right

These days the preference for shoddy, cheap, use-and-discard products is all over the place. Here is an example:

Street sign

This sorry street sign in Jerusalem has taken on a very “artistic” look – because it is made from a blue layer of stick-on plastic sheet over a metal plate. Over time the plastic started to shrink and curl, with this amusing result.

And it occurs to me that the ancients who lived in our city had a better method. Take this stone, which was part of the temple enclosure parapet in the second temple period (around the time of Christ). It too carries a Hebrew inscription, identifying the location of “the house of trumpeting” – the location where the priest stood who blew the ram horn to announce the entry of the Sabbath.

The house of trumpeting inscription, Temple mount, Jerusalem

This stone took a big fall when the Romans destroyed the temple, but the lettering on it is crisp and legible after two millennia.

Sigh…

 

Cornell’s Calculator in a Book

Some of the most fascinating items in my History of Computing collection are the one-of-a-kind, undocumented ones. The latest such addition to the collection is a calculator hidden in a book-like case, that has no mention anywhere that I could find.

This is Charles Cornell’s F.24 aerial photography planning calculator, and you can read all about it in my latest article. Enjoy!

Cornell's F.24 Aerial Photography calculator

Innumeracy in the skies

Was on a United flight enjoying my coffee (such as it was), when I noticed the text on the paper cup.

Nice cup:

Paper cup on United Airlines

Makes them feel very ecological, no doubt… someone in Marketing must’ve though it a good point to brag about.

Except that it’s completely meaningless, of course. This statement remains true even if the cup contains zero recycled material.

Sigh…