Archive for category Home Ec

Encrypted Email: What Could Possibly Go Wrong?

So this arrived from an email address similar to, yet not quite the same as, the URL of a physician’s office where I had an appointment a few days hence:

Encrypted Email Message
Encrypted Email Message

My email client is set to prefer plain text, disallow remote content, and not open attachments, so that’s as far as it got. Donning asbestos work gloves and face mask, I pried open the message and its attached HTML file with the appropriate tools and found, as expected, scripts doing who-know-what.

Called the office and, also as expected, was told my appointment time had been changed.

Showed up, mentioned it to the doctor, and was told the office must check off many boxes to demonstrate its HIPAA compliance.

Bottom line: HIPAA now requires patients (a.k.a., us) to open random attachments from random senders, all in the name of privacy.

Banks do that, too.



Tea Strainer: Tare Weight

Being a responsible consumer, I carefully measure my daily green tea dosage. A laser-cut stainless steel strainer and silicone steam cap recently arrived, with a most auspicious tare weight:

Tea Strainer - 80.88 g
Tea Strainer – 80.88 g

Before my Genuine IBM 5160 PC XT with an 8088 CPU, I scratch-built a Z80 “personal computer” and wrote a primitive multitasking OS. Plenty of electrons have flowed through the transistors since those days.

A great way to start the day; ya can’t make this stuff up!


Stink Bug Haven

We hung a pine-cone wreath beside the back door (a.k.a. the only door we use), replacing a Welcome sign painted on a slate tile. Of course, the tile had long provided a sheltered spot against the house siding:

Marmorated Stink Bugs and Spiders

Marmorated Stink Bugs and Spiders

Reports from the garden suggest Brown Marmorated Stink Bugs aren’t as damaging as they once were, perhaps because something has developed a taste for them.

We hope whatever it might be eats well this year.


Cable Ports vs. Foot Traffic

Spotted this under a counter at Panera Bread:

Power and network cables - floor plates

Power and network cables – floor plates

You’re looking downward from the edge of the communal meal countertop at the power and network cable ports in the floor. The cables snake into the counter legs and emerge at the countertop to provide AC power, USB charging, and wired  network ports in addition to ubiquitous WiFi: all the conveniences of modern dining.

Alas, down at floor level, the poor cables get kicked against the edge of their cover plates, bent with no strain relief, and seem jammed under the sharp edges of the leg extrusions. I expect the connectors below the hatches also endure a nightly bath of gritty water, with bonus salt during the winter months.

And, yes, the AC power plug sits halfway out of its socket, with the blades exposed.


Multimeter Probe Cable: FAIL

A reasonably good silicone-wire multimeter probe set arrived last spring and has worked well enough (I thought, anyhow) for the usual voltage measurements, but recently failed while measuring a small current. We all know how this will turn out, but the details may be of some interest.

Measuring the resistance from tip to plug located the fault to the black probe, after which I poked a pin through the insulation near the plug:

Multimeter probe - diagnosis

Multimeter probe – diagnosis

The two leads near the bottom go to my shiny Siglent bench multimeter. Despite their similarity to the failed probes, I’m pretty sure Siglent has better QC (well, mostly).

The probe’s resistance was near zero from the tip (offscreen to the left) to the pin and megohms from pin to plug (on the right). Figuring the wire worked loose, I pulled it away from the plug:

Multimeter probe - disassembly 1

Multimeter probe – disassembly 1


Although I wouldn’t have trusted those probes anywhere near their alleged 1 kV rating, seeing that exposed copper-like substance was disconcerting.

Hacking off the strain relief bushing around the wire got closer to the fault:

Multimeter probe - disassembly 2

Multimeter probe – disassembly 2

And, finally, the problem becomes obvious:

Multimeter probe - disassembly 3

Multimeter probe – disassembly 3

Yet Another Cold Solder Joint:

Multimeter probe - cold solder joint

Multimeter probe – cold solder joint

Pulling a black banana plug from the heap, I decided to drill a proper hole to anchor the wire:

Multimeter probe - drilling plug

Multimeter probe – drilling plug

Which looked like this afterward:

Multimeter probe - soldered plug

Multimeter probe – soldered plug

And produced a strongly mismatched pair:

Multimeter probe - repaired

Multimeter probe – repaired

Ain’t it amazing how much fun you can have for a few bucks, all delivered by eBay? [sigh]

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Transistor Pricing

You can find anything on eBay (clicky for more dots):

ZVNL110A MOSFET - kilobuck eBay pricing

ZVNL110A MOSFET – kilobuck eBay pricing

The key information:

ZVNL110A MOSFET - kilobuck eBay pricing - detail

ZVNL110A MOSFET – kilobuck eBay pricing – detail

For that price, I’d expect in-person hand delivery.

Stipulated: ZVNL110A MOSFETs aren’t in production and we’re buying from diminishing inventory, but (as of late December 2018) they’re still available for under a buck apiece in small quantities.

It could be a pricing algorithm corner case, a money laundering scheme, or just a typo that could happen to anyone. As the news sites put it, the seller did not respond in time for this posting …


Shoe Lace Ferrules

A new pair of shoes arrived with extravagantly long laces requiring shortening. Years ago, I found heatshrink tubing completely unequal to the task, so I deployed Real Metal:

Shoelaces with crimped ferrules

Shoelaces with crimped ferrules

The ferrules come from a kit of such things, minus their plastic strain relief:

Ferrule terminals - hex crimper

Ferrule terminals – hex crimper

That’s a fancy hexagonal crimper for round-ish results. If you have a square terminal block, you should use the square crimper that comes with the kit.

Worked perfectly and produced immediate customer satisfaction.