Potential Problem With Older Microwaves

[sudsmaster]

We've seen a number of posts here from people who enjoy and search after older microwaves.

While I don't deny that the build quality and design of older microwaves may be more appealing, it's my understanding that microwaves have a certain useful lifetime. After a number of years the magnetron that delivers the energy to the food weakens, and eventually fails. In many cases it's cheaper just to go out and get a new microwave than try to get the old one fixed.

I see this problem all the time in the workplace, where the company has provided microwaves in the lunch room for employees to use. In some cases these units are pretty long in the tooth and often they can take two or more times as long to heat a meal than a newer version.

So I'm wondering... is there something special about an early Amana or Radarrange or Litton microwave that enables them to deliver full power forever? Or are people collecting these because they like the way they look, not necessarily for their ability to heat anything in a timely manner?

 

[retropia]

For me it's just nostalgia. I may use my Radarange to warm coffee in my office, but in the kitchen, our newer over-the-range microwave is more practical as a daily driver. I suppose I could run a test boiling water in a mug in both, to see which is faster. It doesn't really matter to me, though.

There were three Radaranges I used in the mid to late 1970s that hold fond memories for me.

 

[rp2813]

My 1980 Panasonic seemed to do fine up until we left it behind at our other house three years ago.  It was only 750 watts compared to 1,300 watts on the Panasonic we have now, so it for sure did everything slower, regardless of the condition of its magnetron.

 

 

[philr]

I have two older microwaves (a small Hitachi from 1982 and a Frigidaire-badged Amana from 1978) and I use them quite often. I don't have newer stuff and I mostly use them to reheat, which they do quickly. I often set the power level lower on the Frigidaire. A friend of mine has an expensive, 4 years old over-the-range Panasonic microwave oven and last year, his girlfriend heard an explosion while she was using it and it was dead... They had to have the magnetron replaced at about 10 times the cost of my two current microwaves!

I never cared for anything newer! I mostly like stuff from the fifties to the seventies and other than my cell phone, my computer, digital camera, a GPS, toothbrushes, a tv, two vehicles from the early nineties (my newest vehicle is 18 years old while my oldest one is 46), I have very few modern things! Last year, after replacing the motor in my 1990 Toyota pickup, I had the motor replaced in my 1990 electric shaver, the person who replaced it commented that it was probably not worth replacing as the shaver was old, I said it wasn't, I got it new just 21 years ago!, I replaced the batteries just 3 times and the blades once! I'm not the kind of person who likes to replace it's old stuff by newer one if it's still good!

I live with rotary phones, the watch I'm currently wearing is from 1971 and I have no appliance newer than my 1978 and 1982 microwave ovens!

 

[launderess]

As With Everything It All Depends

Upon how "used' the old microwave was during it's previous lifetime.

Given the results many homes didn't use microwaves for more than reheating foods, boiling water, etc. So there could potentially be lots of life left in said oven.

As one who is hunting for a vintage microwave read something on the Interent this week. It came from a repair/tech service that stated all new microwaves loose about 30% of their power within the frist few months of use, then things slowly decline from there.

Consider also like many appliances back then microwave ovens were, for the better brands at least way over built for their purposes. One routinely finds MCs out there >15 years old that apparently are still working fine, the usual reason they are being chucked is due to death of previous owner or a kitchen remodel. Of course the other reason is the desire to have something new.

Aside from the turn table, inverter systems, humidity sensors and perhaps a few things I cannot remember there isn't that much "new" to microwaves. Some old er features such as no turn table at all are making a come back (Panasonic).

 

[philr]

My 1982 Hitachi microwave does have a humidity (or heat?) sensor.

It's great for reheating. Just press one button and it starts and stops automatically.

 

[cfz2882]

usefull life of microwave ovens...

....may well be many decades-my old oct.1984 built hotpoint(GE) microwave still
working like it did when it was bought at K-mart in 1985,this one is my DD
All my other oldies,including '68 radarrange,'70 westy branded RR,all still
going strong.Mechanical parts;fan and stirrer motors,timers, etc seen to give
more trouble than the simple electronics of the magnetron system.

 

[sudsmaster]

Well, granted, the old microwaves at a former employer got a lot of heavy use for years in the company lunchroom. They cooked so weakly that it couldn't be from just a lower designed in wattage rating.

I once had a small Amana badged 800 watt Hitachi microwave. It had no turntable but worked fine. But after about 10 years it suddenly stopped working. I tried replacing the fuse a couple of times but it would blow as soon as the thing was turned on. I replaced it with a Kenmore that is still going strong (along with a Panasonic I got as well). The Kenmore is actually a better designed appliance, IMHO. Its sensor system seems more accurate than the Panasonic, at least for popcorn and beverages. However the Panasonic does have the inverter technology that is nice for re-warming foods (typically I will set a couple of slices of pizza on the inverter defrost setting for about .4 lbs, and it rewarms them perfectly with no overheating).

Perhaps it would be wise, however, to test how long a vintage microwave takes to heat a cup of water before purchase. No sense in paying top dollar for an antique that may need a new magnetron.

 

[launderess]

What Always Gets Me Is

How many persons want nearly a hundred or in some cases several for a "vintage" microwave. I suppose something like a NIB Amana Radarange from a certain period *might* be worth that amount, but not your average daily used machine with the interior coated in cooked on gunk.

As for heating methinks it is not always about watts (heating power), how well the oven was designed to distribute microwaves must come into play as well.

Don't know if this is true but many report their vintage microwaves especially Radaranges heat more evenly and sometimes faster than today's higher watt versions.

 

[whirlcool]

Our old Litton (that is currently sitting unused in the garage) seemed to cook slower and slower over time. When the power surge we had two years ago took out our appliances we used the Litton for a short time again. It has a power rating of 750W.
The Kenmore microwave we had at the time that got blown out by the surge was 1000W.
The Litton took a lot longer to defrost and cook things than the Kenmore did. I thought it was just the difference in power, but it may have been age too. We bought the Litton in 1976 and was in continuous use until 2001.

 

[statenislandgwm]

I have a Radarange that was manufactured in April of 1986. I live in an apartment so it is my daily driver, to me it seems faster than any other microwave I have used. The only problem with it is that I have a friend who won't go by it when it's on, I think the hum of the magnetron is what scares him. LOL!

 

[cfz2882]

blown fuse

IIRC,some microwave ovens have the door interlock switches arranged to switch as
a short circuit and blow the oven's fuse if there is a foreign object in the
latch or other malfunction with the door...thankfully washers don't have that
safety feature LOL

 

[sudsmaster]

"The typical life of a magnetron tube is approximately 2000 hours of operation."

Let's see... if you use a microwave oven for, say 10 minutes a day, and don't abuse it (run it empty, or with metal in it that causes arcing, or have bad line voltage) that means the magnetron may last 33 years. I would say that 10 minutes a day is probably around the average that I might use a microwave. Maybe more.

The microwaves in a company lunchroom are probably used at about an hour a day (two shifts with 30 minute lunch breaks). That would limit their expected lifespan to about 5.5 years.

Compare your usage to these two values and you'll have an idea of how long your microwave may last.

However you generally have no idea how heavily a used microwave may have been used, how it was used or abused, or how long it might last. This might be why the local charities around here (Goodwill, St VdP) refuse to take used microwaves as donations.

http://www.gallawa.com/microtech/Ch7Pg6.html

 

[tolivac]

Besides magnetron tubes in older ovens-how bout door seals-these help prevent leakage of microwave energy.If they are in bad condition--pass.Usual food grime and whatnot can be cleaned away.Don't know if older magnetron tubes for old microwaves are still available.the tube "assembly" consisted of the magnetron itself-and the HV rectifier diodes.they were built into the magnetron assembly.when the tube fails-if it shorts-the diodes fail,too.The "monitor" fuses for microwaves are required by Federal law-they are in ANY microwave.the interlock monitor fuse blows if the door interlock switch shorts,or if someone tries to defeat the door interlock and run the oven with the door open.The idea there is to disable the oven until it can be repaired.the HV rectifier capacitor was separate from the magnetron assembly.It filters some of the "ripple" from the rectified AC-and acts as a doubler device-most microwave HV transformers have sec voltages from 1000V-1200V-the tube runs about 2000-2400V and on the cathode-the anode was "grounded" to the body of the oven.the cathode besides having filament voltage on it-has the pulsing 2000-2400V on it,too.so beware any who wants to work inside the innards of a microwave cooker!

 

[tolivac]

another thing to think about regarding magnetron tube life--remember the tube is cycled on-off,on-off thruout its life.It is not run continuously as most other tubes are.The on-ff cycling does shorten the life of any tube.the filament is stressed-like an incandscent light bub turned on-off,and the cathode gets stressed anytime the HV supply is started.so,a magnetron tube does lead a pretty hard life.Radar and other magnetrons are at least run for long periods of time during use.they will last longer.

 

[launderess]

Am willing to wager many vintage microwaves saw very little use aside from the normal reheating and "nuking" certian meals. I mean really; despite all those wonderful looking dishes and recipes microwave makers churned out in cook books, there is really only a limited array of food that "cooks" well in a plain MC. Even worse early microwave ovens often cooked very unevenly. Turning a rack or plate of nibbles for a cocktail party into stuff swiftly chucked into the rubbish behind the hostess's back.

 

[philr]

"The on-ff cycling does shorten the life of any tube  "

Tolivac,

Does that means that the very quick "on/off" cycling of the magnetron in my older (Frigidaire/Amana) microwave oven (when using it at less than full power) is harder on the magnetron than it would be on newer microwave ovens?

 

[tolivac]

In most "older" microwave ovens only the HV supply was cycled on off for lo heat or defrosting.A separate transformer supplied the filament voltage for the magnetron.Another transformer supplied the HV the primary side of the HV transformer was cycled on-off or varied thru a Triac type device to provide the lo heat or defrosting effects.so,when you started the oven-the filament transformer would light the magnetron-the HV would be cycled on-off during the cook cycle.The filament would stay on during the cycle.I think newer ovens do the same sort of thing.somewhere at home have a service book on old microwaves.In new microwaves the HV would be "modulated" by varying frequency and wave duration to give the heating effects desired called for by the cooking cycles-the device there is sort of like the pulse modulator for a radar magnetron.the filament would stay on during the cycle.then switched off when the cycle was over.In radar transmitters the fil stays on until the operator turns the fil switch off on the transmitter.the switch in that case is interlocked thru the HV supplies-they are switched off,too.Good only for emergencies-you could blow the manetron in that case.

 

[aquarius1984]

Well,

Im not so sure, confused for sure here!

I own my Grans brother hi Speed microwave which if IIRC was bought in 1992 and was used intensively for 12 years before my gran passed away. She used it to cook whole sunday roasts, meat portions, cakes, pastries, oven chips, vegetables, roast potatoes and all kinds of things.

After 2003 my grandad has used it solely for re heating meals and warming up cups of milk, and yet it still performs like its almost new from its box.

Im able to cook a whole roast chicken in 3o minutes using the Hi Speed sensor cooking and not any old chicken either, flesh soft as butter and yes the skin is golden!

Have even cooked a full meal of pork steaks, baked potatoes and roast mediterrenean veggies in around 35 minutes.

Sausages roast in 15 minutes, bacon to go with it in an extra 5 if the oven is hot. bacon placed on top of the sausages to heat off their heat.

Warms a cup of milk in 1 minute 30 seconds, about the time most modern microwaves seem to take I have found.

Looking to stock pile spares for sure, I aint taking a risk with this one, I want it for life.