New Toy: Kenmore 1.6 cu. ft. Countertop Microwave

In the 1980’s my parents got a microwave oven, an Amana Radarange.  They replaced it and gave it to me, and although it took a longer time to cook than when new it otherwise worked fine until a couple of years ago when the buttons became iffy and I had to retire it to the curb.

Then I got a Haier for a Benjamin and it also served me well enough, I guess.  Beeped too much, it did.  Beeped when you pressed a button, any button.  Beeped three angry times when you pressed the wrong button, as if to say, “No, you can’t enter a new cooking time, I just finished cooking and you must acknowledge this by opening the door or pressing <Clear>!” (not the best microwave oven anthropomorphization, granted).  Beeped proudly four times when it finished cooking (and if it had legs I imagine it would do so while strutting like a rooster).  Such an attention whore, it would beep impatiently three times every couple of minutes after that if I didn’t open the door or press <Clear>.  Chatty bastard.  I would have clipped a wire to the speaker had I the audacity to open it up, or, you know, set it on “mute” had I the option.

It otherwise performed well until a couple of months ago when I noted that the plate was turning around in a somewhat herky-jerky fashion.  Odd, that.  Closer inspection revealed that in the tracks of the “turntable guide roller support” (aka the round-around circle with the little wheels) there was a spot of bubbled-up paint, and rust.  Well, that won’t do, so I cleaned it and then coated it with clear nail polish and hoped for the best.

Worked for a while, it did, and then not so much.

So I bought an ounce of clear nail polish and tried the same thing again, expecting a different result.  That worked out even less well; very slow to dry, a persistent odor of chemical nastiness, and to my dismay, the rust problem continued to worsen.  I also noticed that rust was appearing in the microgaps where the walls of the oven met.  I’d had this thing for less than two years, and I’d bought it new.  Apparently leaving condensate water to stand is not conducive to microwave oven longevity.  Who knew?

Enter the new kid: a Kenmore countertop (model 73169), 1.6 cubic feet and 1100 watts.  Kenmore is a Sears brand, and they don’t make microwaves; from what I’ve read they select a model from an established manufactured, slap on their badge, and Presto! it’s a Kenmore now (OK, OK, Presto doesn’t actually make any products for Kenmore, it was just a joke).  Kenmore, because the sale price was not hideous, and for now I’m done with Haier.

The interior capacity is cavernously enormous; 1.6 cubic feet and the glass plate is, what, 12 or 14 inches across?

– “Gee, you’ve got a big microwave!” “Gee, you’ve got a big microwave!”
– “Why’d you say that twice?”
– “I didn’t!

It looks easy enough to keep clean, which I’ll be doing assiduously with a retired dishrag.  Learned my lesson on that, damn straight.

The thing works OK, too, but curiously it sometimes pauses the cook cycle as it counts down.  That is to say, when I set it to cook on full power for some minutes it will, at some point, turn off the microwave emitter yet continue to keep the interior light on and spin the plate.  It looks busy, but it’s not – I can hear the fan spin up to a higher rev and I can see lights in my kitchenette get brighter when it does this.  I think what’s happening is that the humidity sensor has detected a dropoff and so it cuts power for a spell.  This behavior is similar to some preprogrammed functions but is not documented per se, insofar as I can tell, hence my speculation.  Also, if it’s been doing that on-off thing, it turns off the emitter for the last 18 seconds or so of the cooking time.  Regardless, the food does get cooked in less time than the cursed Haier, so there’s that.

It does seem to cook more around the edges, and sure, what with the microwave emitter being on the sidewall of the unit that might be expected, but the same could be said of the Haier unit I had and the heat distribution was more uniform in that unit and every other similar microwave oven I’ve used.   I suppose the internal reflectivity must be different in some way that’s undescernable to me.

Unfortunately, the round-around circle with the little wheels came broken in the box, so I called up the folks at Kenmore and told them of my trouble.  They shipped out a replacement which arrived within a couple of weeks.

Oh, and it beeps.  A beep for every keypress, five beeps when finished, and then, blessedly, silence.



Modern Electronics Designed to Fail. Yay.

[by Mr.Hengist]

Interesting: “It is by no means uncommon” for modern IC integration design engineers to assume the fast obsolescence of the end product, and therefore IC environmental protections are not incorporated. Such devices will therefore have short lifetimes by design, and while that’s not a problem in market due to fast obsolescence, it means that you’re SOL if you want to keep such a device for an extended period of time.

It reminds me of the story of Henry Ford, who perused junk yards for his cars. He asked the proprietors which parts lasted longest, and then instructed his engineers to make those parts more cheaply because, by his reasoning, they were overbuilt.

Anyways, here’s the relevant quote:

The traditional functions of a semiconductor device package are to protect the die from degradation by the atmosphere and fan-out the electrical interconnects to the next level. Because of the benign environment in which most modern semiconductors are used coupled with short expected life through product obsolescence, the need for the package to provide environmental protection has virtually disappeared. It is by no means uncommon to see essentially package-less chips attached to circuit boards, with just a polymer covering over the exposed bond pads.

Controller Doubles Effective Lens Diameter of Telescopes

[by Mr.Hengist]

Mr.Science pulls a technorabbit out of a hat:

“Technology to double the effective lens diameter of the world’s telescopes has been invented at the University of Montreal, which recently demonstrated what it says is the most sensitive astronomical camera devised to date.
“The key to the invention is an electronic controller that decreases optical noise tenfold.”

Ta-Da! I love technological advances such as this one, which adds what should be a relatively low-cost doohickey to existing high-cost equipment in order to give it a major boost in capability. Congratulations to our fellow propeller-beanied Canuck friends up north. The semi-informative article is here; no word on licensing fees or the cost of the doohickey.