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Author: Subject: Bottom zapper
wg48temp9
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[*] posted on 2-1-2022 at 03:36
Bottom zapper


No not anything to do with kinky electro stimulation LOL.

My first microwave oven was a bottom zapper. The microwaves entered the oven chamber through the bottom of the oven that was covered by an sheet of hard plastic. It was very effective for heating mugs of milk for coffee. Some other microwave ovens had the microwaves enter from the top usually with a rotating fan like disc to stirrer the waves around. What I found was the top zappers tended to mostly heat the top surface of liquids while the bottom zappers did not.

I was reminded of this yesterday as I was given a microwave oven that looked like a bottom zapper. It turned out to be a side zapper with only a stirrer on the bottom bellow an hard plastic sheet.

I would like to test how evenly different microwave ovens heat so I need a compound or a mixture that when mixed with a water gel that permanently changes colour when it reaches a temperature say above about 80C, preferable permanently. I can not think of anything simple that will do that.
Perhaps starch and an iodine compound that release iodine when it gets hot say nitrogen triiodide its heat sensitive. Anyone got any ideas preferable not using anything too exotic.

PS: Happy new year to all our Sciencemadness people.

[Edited on 1/2/2022 by wg48temp9]




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Sulaiman
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[*] posted on 2-1-2022 at 03:51


a block of butter will reveal hot spots quite clearly.



CAUTION : Hobby Chemist, not Professional or even Amateur
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wg48temp9
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[*] posted on 2-1-2022 at 05:06


Quote: Originally posted by Sulaiman  
a block of butter will reveal hot spots quite clearly.


Yes that will work particularly if I use the low fat version which is about half water or buttermilk. I could cut the cold block in to a mug sized cylinder and after its zapped slice it up.

I have noticed an odd arrangements hot spots in blocks of butter if I zap it too long to soften it. I have put that down to standing waves in the block. I assume the approximately 50% water version of butter should reduce that effect making it more representative of water and I can still use it for my morning toast LOL




I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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Morgan
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[*] posted on 2-1-2022 at 11:21


A little after 8 minutes he shows how a box revealed hot spots.
https://youtu.be/OyTmJX_TC84
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wg48temp9
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[*] posted on 3-1-2022 at 04:57


I just remembered which thermochromic compounds I thought I should consider to indicate gel temperature. It was the Chemical christmas decorations section of https://colourchem.wordpress.com/main-page/
ie our Bedlasky's chemistry site.




I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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crow6283
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[*] posted on 4-1-2022 at 13:04


Would you share what model microwave you use?? Every single microwave I’ve taken apart (well into the hundreds) effectively has their magnetron in the same place. I wonder what about the design of your microwave makes it heat from the bottom?
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wg48temp9
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[*] posted on 4-1-2022 at 18:14


Quote: Originally posted by crow6283  
Would you share what model microwave you use?? Every single microwave I’ve taken apart (well into the hundreds) effectively has their magnetron in the same place. I wonder what about the design of your microwave makes it heat from the bottom?


My first microwave oven was definitely a bottom zapper. that was more than 30 years ago. I remember it because to dismantle it I had to remove shelf by cutting the slicon rubber used to seal the shelf. The microwaves entered the oven through the bottom wall below whatever was being heated. It had a drop down door with the electronics and magnetron in the bottom of the housing with the controls below the drop down door. I particularly purchased it because it had a small footprint. I do not recall its make and model. The magnetron's copper output stub was inside a glass thimble. I don't think I have seen a bottom zapper since. Yes they are mostly side zappers these days or the ones I found or been given are, with occasionally a top zapper..

The recently obtained side zapper with a rotating stirrer inside the oven chamber at the bottom but isolated from the chamber by what I think is a hard plastic shelf. Presumably that is transparent to microwaves. The stirrer redirects the microwaves to better heat the food from below. But it is a side zapper, meaning the microwaves enter the oven from a port in the sidewall of the oven chamber.

Its a Samsung CM1099.
You can see a video of the oven at https://www.nisbets.co.uk/samsung-light-duty-1100w-commercia...

You can see the bottom shelf in the video. The shelf is removable when I removed it I discovered the stirrer. I thought it was unusual having stirrer (mode stirrer) on the bottom of the oven and not in front of the microwave port at the top of the oven.







I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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crow6283
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[*] posted on 4-1-2022 at 19:52


Interesting. Yeah all the ones I see have the magnetron on the side, right next to the transformer and capacitor. I once saw an older model microwave at a university surplus sale that had all sorts of bells and whistles including fittings for condenser, addition funnel, etc. I don’t know why I didn’t buy it but I must have just not been thinking that day.
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wg48temp9
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[*] posted on 5-1-2022 at 04:44


Samsung CM1099 Is a an excellent microwave oven apart from the manual controls. Its difficult to set the mechanical timer accurately for less than about 2 minutes and it powers up when the door is closed. Its all stainless steel inside and outside apart from the inner side of the door.

As can be seen from the ad it apparently is still made even though the manual was written in march 2013 suggesting its an about 10 year old design.The only thing wrong with it is the power selection control knob is missing.

I was hoping it was the inverter type but the weight suggests its not. Oddly at low power levels you can not hear the on off control. If I do scrap it I should get at least a 1.4kW HT transformer from it and perhaps with copper windings.

PS: In addition to the missing control knob the oven light is faulty.

[Edited on 1/5/2022 by wg48temp9]




I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
View user's profile View All Posts By User

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