Sharp Microwave Saga - The Last Shout. Repair or?

[hydralique]

Sharp was always a Japanese company, but expanded into the US in a big way in the '70s and '80s. My guess is that the microwave market in the US was much larger than anywhere else in the '80s and that combined with the high cost of shipping those tank-like ovens it was just simpler and cheaper to make them here.

Sharp makes pretty good copiers. We've got one, purchased from our copier repairman as he prefers them to any other brand he services.

 

[rp2813]

Temp Probes and Turntables

Rich, my 1980 Panasonic (which I am starting to miss a little) had a swivel receptacle at the top center of the oven cavity, which allowed the probe cord to rotate along with the turntable.

My partner and I cruised our old place recently and saw the Panasonic out at the curb. I suspect it still worked fine and was a case of operator error. She probably accidentally turned the "temp cook" knob used with the probe, which will stop all operation unless the probe is deployed. Either that or the slight squeal the turntable was making scared her. I was tempted to rescue the oven but truly, I have no place to put it and there's already enough stuff stored around here.

 

[launderess]

My Sharp microwave was produced in 2000, and was made in the USA, according to the plate inside the oven. Headquarters was in New Jersey, Matawan or some such place.

Radaranges:

Yes, vintage Amana Radaranges are the "battleships" of microwaves. Sadly from what one hears parts can be hard to come by, so when they finally do give up the ghost, repairs may not be easy.

Was reading a book on the history of the microchip on Google last night, and it covered the history of the microwave, starting with Amana being purchased from Raytheon (sp?), and the launch into making microwaves a consumer product.

First, their was confirmation of what was said up thread, microwaves on full power would defrost foods unevenly, and worse begin cooking the thawed part before the balance. Yes, it went into why (something about ice, water, heat, waves......). So Amana sent their engineers to work designing a way to throttle power up and down to get even results in defrosting and cooking.

Apparently when the head of Amana went on a tour near the company's headquarters of engineer's homes, he found their wives loved the first microwave ovens, but the things were huge, almost the size of a small fridge today. Engineer's wives were the only one's to have the units, since they were so heavy, big and expensive. Amana's goal was to bring down the size and price of units. Though they did bring down the size (if not weight), the units still cost dear for the period.

 

[launderess]

Personally think much of the "problems" with today's microwave ovens, including product lifespan have to do with making the things into something they aren't.

Try as hard as one might, microwave cooking is never going to give one the same results as oven or range top cooking. It is just a matter of simple physics. One can achieve some browning and crispness via special dishes/cookware and or adding features such as convection and or heating elements, but the results are often less than perfect. Consumer Reports has repeatly tested all sort and manner of "speed" ovens, combinations of microwaves and such, all with mixed results.

One would never bother making a rib roast in a microwave. For all the bother it takes, (with less than great results), one can prepare and bung the thing into the oven and be done. Of course during warmer months, one may seek out cooler ways to "roast", but for those times there are plenty of small electric ovens/roasters around. Or, simply take a tip from our grandmothers and have some sort of "summer kitchen" set up either in the basement or a room off the kitchen.

 

[rp2813]

My sister and I received our matching 1980 Panasonics as Xmas gifts from Mom and Dad. I went back to the store with mine with the intention of trading it for an identically priced Radarange. The sales guy talked me out of it, advising and demonstrating that the Panasonic was a superior machine. I can't complain about the longevity of the Panasonic, it served me beyond my wildest expectations, but even now I still lust after a Radarange.

 

[sudsmaster]

The technical reason why microwaves can't heat up ice is that a microwave works by exciting hydrogen bonds. The excitation makes the molecules held by the bonds move in and out, and that motion in turn translates directly into heat. There are lots of hydrogen bonds in water, but when water is frozen these bonds are held rigid and can't get excited much, their associated atoms (hydrogen and oxygen) can't move much, and not much heat is produced. The lower power levels are needed to gradually produce enough heat to melt enough water that its hydrogen bonds can be excited and produce heat to melt more ice and finally cook the food.

Fats contain hydrogen bonds as well, but they are mostly hydrogen-carbon. But fats can certainly be heated by microwaves, and since fats can't release that heat by turning into steam at 100C, they can get a lot hotter than water in a microwave. Which is why fatty foods can melt plastic microwaveable containers. Carbs and proteins also contain hydrogen bonds, and I'm sure we've all seen the edges of larger pieces of meat turned to leather by too much heating too fast in a microwave on full power. But I also think the atoms in such carb and protein molecules are held somewhat more rigidly than in water or fats so they don't heat as readily. But there is still plenty of water associated with proteins so that they can overcook quickly around the edges since microwaves don't penetrate that far into an object to begin with.

Laundress is absolutely right that one can't achieve the same results in microwave cooking as with oven/rangetop/bbq/rotisserie methods. Microwave cookery, at its best, is a form of steaming, and proceed accordingly in preparation and arranging the food stuffs. Adding a little water to things like fresh veggies helps a lot in cooking them, and the small amount doesn't dilute the vitamin content that much. Similar to the "waterless" cooktop steaming of veggies, in which a small amount of water is used in a pot with a tight fitting lid, and once the water has produced steam the heat is reduced enough to ensure cooking but not to boil the water all away before the food is cooked. Nothing worse than the aroma of burnt broccoli!

 

[rolls_rapide]

Sharp Microwave Ovens

The mica wave-guide cover (looks like grey cardboard) has a tendency to wear out. I didn't like the look of that in the shops in 1990, and years later, a work colleague said his Sharp caught fire!

I had a Panasonic that saw daily use over 8 years. It had a wipe clean plastic cover.

The modern Panasonics have the lightweight 'Inverter' power supply, that does away with the heavy transformer; makes it easier to lift.

 

[launderess]

"since fats can't release that heat by turning into steam at 100C, they can get a lot hotter"

Which explains the theory behind the various browning and or grill ware sold for use in microwaves. Bascially nothing more than a surface that will get VERY hot when preheated in a microwave. Then just as with a skillet or fry pan one uses on the range, meat is placed onto the hot surface which in theory should sear.

Say "in theory" as some browning dishes worked better than othters. Corningware supposedly had a rather good set, but they stopped production because consumers not understanding how to use the dishes, didn't get the proper results. Also the browning dishes were the only ones produced by Corning at that time which absolutely could NOT be used on top of the range. Suspect more than a few housewives plopped those special skillets on to their range tops and destroyed the coated bottom surface, which was what did the "browning".

Oh, the other problem with microwave browning dishes is that one has to turn the foods over to "fry" the otherside before the device looses the proper heat.

 

[launderess]

Never bothered to add water to veggies before microwaving.

Then again wash fresh veggies to within an inch of their lives, so perhaps there is enough water residue to get things started.

Frozen veggies I find usually have enough "frost" on em to start things off. If you like olive oil on your veggies, it's best to put it on after nuking, this helps preserve all the anti-oxidants.

"Steaming", exlains why white meats such as fish and poultry can be "cooked" in a microwave with pretty good results.

Red meats such as beef tend to look like they are boiled, however some dishes that is what one is going for, so it may be ok.

 

[sudsmaster]

Those mica covers always seem to get so grody in corporate ovens. For quite a while I so disliked that mica magnetron shield that I would only purchase microwaves with plastic shields. The Kenmore is one of them, also the Magic Chef, as was the Amana-tachi. The Panasonics all seem to have mica covers and I finally broke down and got one because I wanted the inverter technology. I have found that, unlike shared corporate microwaves, the mica cover in my Panasonic stays very clean so it hasn't been a problem. That's because I am usually careful to cover anything that might sputter, and clean up any mistakes right away before they can get baked on.

Even for frozen veggies, which usually have a surplus of water, that water is frozen and won't heat properly until thawed, so a little water added can greatly improve microwaving results. No more than a tablespoon or two is needed, just to get the ball rolling, so to speak.

 

[rolls_rapide]

Ah yes...

I remember now, Panasonic microwaves 'with grill' have the mica cover. Standard Panasonic microwaves have the plastic version (or at least they did have!).

 

[alr2903]

I once had a co-worker tell me her husband actually thought they could get rid of their stove after they received a microwave for Christmas of course this was back in the late 1970's. With gimmicks like Littons "meal in one" and other slogans, it is kind of cool to look back at our expectations. I like the look of the mw/vent hood, but i am always leary of any type of "combination" appliance or electonic gizmo like dvd/vcr players, your SLC (stuck like chuck) when one of the functions goes on the blink.alr2903

 

[launderess]

Slow My Roll

Just recalled and related the following problems to the repairman.

For about a month or so noticed items placed in the oven sometimes weren't "done" the way they used to be when using the sensor settings. Things such as frozen veggies that normally required nothing more than hitting "frozen veggies" button and "start", would sometimes come out not quite done. Ok, darn right cold in certian areas. That never happened before.

Also there was a faint scent of burning electrics from the air exhausted from the unit (via the fan that vents hot air/steam out).

Wanted to have this on record, so the magnetron (sp?) could be tested, and or anything else. If it is the magnetron (sp?), then the unit will have to be chucked. That part cost dear, and doubt Sharp will send a new one under warranty for an almost nine year old oven (warranty only covered five years).

L.

 

[sudsmaster]

On a microwave that old, the magnetron is a prime suspect.

Especially if you used it several times a day for major cooking.