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Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details. |
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20th May 2014, 4:03 am | #1 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,924
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Leakage from ageing Microwave ovens?
While the "built to last, not surpassed" phrase strikes a chord with many on the forum, I was just listening to a radio programme which raised the issue of domestic microwave ovens going for years (decades?) without being leak-tested.
Commercial leakage testers are more expensive than an oven; has anyone cobbled something together from their junk box? I guess that calibration would be the problem? B |
20th May 2014, 7:34 am | #2 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
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Re: Leakage from ageing Microwave ovens?
It depends what your junk box is like
A dipole added to a connector fitted to the head of an HP power meter ought to be fairly predictable. Then there's the 8566B sitting waiting for me to get round to it... I'm not sure I'd want to risk a power sensor head, the prices on Ebay reflect that their population is falling (probably due to whoopsies rather than unreliability) Of course, something like this could act as reference for a dipole and diode on a bit of PCB. Someone asked me to look at a microwave cooker whose electronic timer kept losing its marbles. What I saw had me dash out the room and throw the main consumer unit switch before I came back and unplugged the thing. Spot welds had corroded in a cheap painted mild steel housing and there was arcing where the sheet steel had been joined. THere was no way I was approaching it to turn it off. David
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20th May 2014, 8:25 am | #3 |
Hexode
Join Date: May 2010
Location: Coventry, Warwickshire, UK
Posts: 374
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Re: Leakage from ageing Microwave ovens?
We had a very early Tricity microwave come in to work. It had the lowest leakage reading I have ever measured!! Not many of the 80s/early 90s ones fail! It's usually the cheaper modern offerings that fail on high leakage!!
Jan |
20th May 2014, 9:04 am | #4 |
Retired Dormant Member
Join Date: Mar 2011
Location: Hertfordshire, UK.
Posts: 208
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Re: Leakage from ageing Microwave ovens?
I will carry on using my Bejams microwave than.
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20th May 2014, 9:25 am | #5 |
Dekatron
Join Date: Mar 2008
Location: Worthing, West Sussex, UK
Posts: 5,185
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Re: Leakage from ageing Microwave ovens?
I am still using my 1980's Philips/Whirlpool microwave, it was given to me by a neighbour that told me it was not safe as the door had broken.
This turned out to be the outer plastic door trim, I checked it for leakage using a friends microwave tester, as suspected it was fine and is still working well 20 years on! I would be more concerned using one of those cheap flimsy things sold in supermarkets for around £40. I recently rescued a rather nice stainless steel Panasonic microwave from a skip, this uses an inverter rather than a transformer, so is amazingly light. It also has a halogen grill. I soon found out why it had been thrown out, the turntable motor was burned out, but I managed to find a replacement from another scrap microwave Mark |
20th May 2014, 9:37 am | #6 |
Octode
Join Date: Jul 2009
Location: Carmel, Llannerchymedd, Anglesey, UK.
Posts: 1,498
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Re: Leakage from ageing Microwave ovens?
I would not panic as cpl. Jones would say. The chaps working on the 10 cm radar stuff used to put there hands close to the output stub to see if they could feel the warmth of the emissions! They managed to survive it. The inverse square law is your friend, but obviously a check for something in continual use is advisable.
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20th May 2014, 10:00 am | #7 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: Leakage from ageing Microwave ovens?
Re. inverse square law, does anyone actually hang around near one when it's working? I imagine the usual modus operandi is to bung something in, set the timer, then cross the kitchen to fill the kettle/ prepare a meal/ go into another room and communicate with a fellow human. When it goes beep, beep, return to it.
I feel a weary groan coming on at the phrase "years without being leak-tested"... Do I sense yet another well-meaning intent in danger of being seized on by bossy, intransigent, dim-wits for commercial gain of vested interests? Radio Wrangler's example is alarming but surely unusual. |
20th May 2014, 10:28 am | #8 |
Octode
Join Date: Jun 2011
Location: West Midlands, UK.
Posts: 1,571
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Re: Leakage from ageing Microwave ovens?
I have a mid 1980s Zanussi in store as a back-up. I suspect that if it was hung from a chain on a crane it would easily demolish the proverbial brick outhouse.
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20th May 2014, 10:31 am | #9 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,788
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Re: Leakage from ageing Microwave ovens?
I still use a no brand oven that I bought in 1988.
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20th May 2014, 11:29 am | #10 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,315
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Re: Leakage from ageing Microwave ovens?
"Radio Wrangler's example is alarming but surely unusual."
Guess it was, but as an engineer (not on microwaves though) I would always take covers off and look first at any item for repair before plugging it in. Found many a fault without having to power things up and often saved a possible fire etc. due to customer putting in a bit of fence wire as a fuse. |
20th May 2014, 12:12 pm | #11 |
Octode
Join Date: Apr 2007
Location: Hampshire, UK.
Posts: 1,574
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Re: Leakage from ageing Microwave ovens?
Wasn't this leak testing thing a scam? Domestic oven don't have any "seals" as such and rely instead on the geometry of the housing. It should follow then that so long as the chassis isn't bent or the door hinges completely worn out then the sealing should be as good as when it was made, what else could possibly go wrong?
More of an issue is the interlock, they are usually quite elaborate and include shorting switches to "crowbar" the fuse if anything goes wrong but I suppose that mechanisms can stick and microswitches fall apart inside, this would seem to be more worth checking than leakage. Our everyday oven is a Philips one from the late 80s. It is impossibly flimsy (the oven cavity liner and the outside of the cabinet are merely different sides of the same piece of metal!) but I have no real concerns about it, I quite fancy one of those Matsushita / Panasonic professional ones but am never in the right place when one is scrapped... |
20th May 2014, 12:37 pm | #12 |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,061
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Re: Leakage from ageing Microwave ovens?
I am still using my first microwave oven, a simple Panasonic bought new in 1994.
The interlock / door latch needed repairing, but that's it so far. I wish I had bought a stainless steel one - the acrylic paint finish is wearing though where the dish rotates on its little wheels. Hasn't worn through the metal though Performance seems as good as ever. |
20th May 2014, 12:58 pm | #13 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,315
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Re: Leakage from ageing Microwave ovens?
My microwave does have seals on the door - they are magnetic strips built into the door and touch the stainless steel frame of the oven cavity. It is quite old now - 1986. It is worth keeping the inside clean and if steamy to leave the door open or wipe it dry. That'll stop the rusting.
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20th May 2014, 4:36 pm | #14 |
Hexode
Join Date: Dec 2012
Location: Carmarthen, Carmarthenshire, UK.
Posts: 268
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Re: Leakage from ageing Microwave ovens?
My first microwave bought new about 30 years ago. I think it was a Panasonic. I took out the 5 year 'warranty' as it seemed a wise precaution.
Guess what happened about 5 years and 1 month later. It started to imitate an arc lamp. My son, who was about ten years old at the time, dived over and pressed the door open button. Stuart.
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20th May 2014, 4:46 pm | #15 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: Leakage from ageing Microwave ovens?
My Bosch microwave/oven must also be from the 80's. It stopped working when I installed a new kitchen and we used it as an oven, but cleaning the mica window got it working again. Its on its last legs as the ceramic wheels on the turntable keep dropping off.
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20th May 2014, 5:55 pm | #16 |
Octode
Join Date: Jul 2005
Location: Newport, Gwent, UK.
Posts: 1,623
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Re: Leakage from ageing Microwave ovens?
Hi,
Sharp microwave (stainless steel) bought in 1984 - still going strong. Michael |
20th May 2014, 7:44 pm | #17 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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Re: Leakage from ageing Microwave ovens?
Hi Folks, If anyone has back numbers of ETI, I believe they published a microwave oven leak detector circuit in the 70's or 80's. From memory it only used standard components, nothing exotic.
Ed |
20th May 2014, 8:46 pm | #18 |
Octode
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,515
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Re: Leakage from ageing Microwave ovens?
Tandy used to sell them. No idea how effective/accurate they were.
Regards, Paul (Panasonic from 1990, still going) |
20th May 2014, 8:51 pm | #19 | |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Leakage from ageing Microwave ovens?
Quote:
The Bosch was replaced with another Panasonic model - stainless steel, so no paint problems, and light becuase it uses an inverter.
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Chris |
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20th May 2014, 9:04 pm | #20 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: Leakage from ageing Microwave ovens?
Exactly! No doubt one could concoct an official-looking box and wand consisting of long-wave ferrite rod, OA91 and alarmingly-labelled micro-ammeter and wave it round the scan-coil vicinity of a CRT TV. Aaaargh, radiation.
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