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-   -   Use old microwave cabinets? (https://www.radiobanter.com/homebrew/145037-use-old-microwave-cabinets.html)

terry July 6th 09 05:41 PM

Use old microwave cabinets?
 
Has anyone had the idea of (or actually used) scrapped microwaves as
equipment cabinets for home-brew projects?
Seeing a nice small stainless steel one (physically intact) while at
the garbage dump (tip) other day renewed the thought!
Ideas?

Paul P[_2_] July 7th 09 03:28 AM

Use old microwave cabinets?
 
I can think of one use if the shields/seals are intact. As a prototype RF
"silence" cage for testing noisy or low noise amps and such. Perhaps that
Hash generating switching supply or bubble jet printer. The fan should help
keep the gear cool.

What would a Steampunker do with one???
This for example:
http://forums.sketchucation.com/view...18097&p=149778

Paul P.


"terry" wrote in message
...
Has anyone had the idea of (or actually used) scrapped microwaves as
equipment cabinets for home-brew projects?
Seeing a nice small stainless steel one (physically intact) while at
the garbage dump (tip) other day renewed the thought!
Ideas?



Paul Keinanen July 7th 09 08:21 AM

Use old microwave cabinets?
 
On Tue, 07 Jul 2009 02:28:35 GMT, "Paul P" REMOVE paul @ REMOVE
ppinyot . REMOVEcom wrote:

I can think of one use if the shields/seals are intact. As a prototype RF
"silence" cage for testing noisy or low noise amps and such.


This may be of interest if you are building 13 cm equipment, but since
the seals are usually resonant traps tuned to 2450 MHz, the
attenuation on other frequencies can be quite low.

Paul OH3LWR


stan July 7th 09 08:14 PM

Use old microwave cabinets?
 
On Jul 7, 5:21*am, Paul Keinanen wrote:
On Tue, 07 Jul 2009 02:28:35 GMT, "Paul P" REMOVE paul @ REMOVE

ppinyot . REMOVEcom wrote:
I can think of one use if the shields/seals are intact. *As a prototype RF
"silence" cage for testing noisy or low noise amps and such. *


This may be of interest if you are building 13 cm equipment, but since
the seals are usually resonant traps tuned to 2450 MHz, the
attenuation on other frequencies can be quite low.

Paul OH3LWR


Paul: That's interesting 2450 megs being around 12.2 centimetres
wavelength????
I'd alway thought they were just some sort of RF seal along edges of
the case!
Never thought about that whie repairing several except to get the
seals correctly back in place.
Thanks for the comment.
However my original thought was that an old microwave; because
frequently dumped when they go wrong due to a) Cost of labour, skills
and tools are needed for repair, and b) New ones can be bought
cheaply; is a ready made cabinet for some home brew project?

raypsi July 13th 09 04:02 AM

Use old microwave cabinets?
 
Hey OM:

Microwave ovens are built for a price, the cheaper the better. The
chinesse have alot of crap out there. Even the fans are junk. I mean
who uses a shaded pole syncro motor for a fan these days, power hungry
junk. Best you could get out of a microwave oven is the metal cabinet
can be cut up with scissors, that's right, dollar store scissors, will
cut the sheet metal they use on microwave ovens. And with a good brake
you can make a lot of project boxes.

Well stainless steel project boxes would look sweet.

73 OM
de n8zu



stan July 16th 09 03:52 AM

Use old microwave cabinets?
 
On Jul 13, 1:02*am, raypsi wrote:
Hey OM:

Microwave ovens are built for a price, the cheaper the better. The
Chinese have a lot of crap out there. Even the fans are junk. I mean
who uses a shaded pole syncro motor for a fan these days, power hungry
junk. Best you could get out of a microwave oven is the metal cabinet
can be cut up with scissors, that's right, dollar store scissors, will
cut the sheet metal they use on microwave ovens. And with a good brake
you can make a lot of project boxes.

Well stainless steel project boxes would look sweet.

73 OM
de n8zu


Yup somebody gave me a stainless four section container which appears
to be unused and from an old fashioned ice-cream parlour/soda
fountain. There is also a single container, same depth and height etc.
And there is a nice rim around the open ends to which a front panel
could fastened!
Immediately thought of ready-made small equipment cabinets!
Scrapping a bunch of old microwaves is what raised the question of a
reuse for the cabinets. We had a school cafeteria operation one time
with three or four m.waves in use for short periods, on several
occasions was able to scrap older ones for parts for repairs. Now just
junk lying around!

JIMMIE July 18th 09 08:49 PM

Use old microwave cabinets?
 
On Jul 15, 10:52*pm, stan wrote:
On Jul 13, 1:02*am, raypsi wrote:

Hey OM:


Microwave ovens are built for a price, the cheaper the better. The
Chinese have a lot of crap out there. Even the fans are junk. I mean
who uses a shaded pole syncro motor for a fan these days, power hungry
junk. Best you could get out of a microwave oven is the metal cabinet
can be cut up with scissors, that's right, dollar store scissors, will
cut the sheet metal they use on microwave ovens. And with a good brake
you can make a lot of project boxes.


Well stainless steel project boxes would look sweet.


73 OM
de n8zu


Yup somebody gave me a stainless four section container which appears
to be unused and from an old fashioned ice-cream parlour/soda
fountain. There is also a single container, same depth and height etc.
And there is a nice rim around the open ends to which a front panel
could fastened!
Immediately thought of ready-made small equipment cabinets!
Scrapping a bunch of old microwaves is what raised the question of a
reuse for the cabinets. We had a school cafeteria operation one time
with three or four m.waves in use for short periods, on several
occasions was able to scrap older ones for parts for repairs. Now just
junk lying around!


I saw one at a hamfest in the tailgate section someone was trying to
sell that was turned into a HV power supply and it used a pair of
microwave oven transformers.

Jimmie

brian whatcott July 18th 09 09:57 PM

Use old microwave cabinets?
 
JIMMIE wrote:
On Jul 15, 10:52 pm, stan wrote:
On Jul 13, 1:02 am, raypsi wrote:

Hey OM:
Microwave ovens are built for a price, the cheaper the better. The
Chinese have a lot of crap out there. Even the fans are junk. I mean
who uses a shaded pole syncro motor for a fan these days, power hungry
junk. Best you could get out of a microwave oven is the metal cabinet
can be cut up with scissors, that's right, dollar store scissors, will
cut the sheet metal they use on microwave ovens. And with a good brake
you can make a lot of project boxes.
Well stainless steel project boxes would look sweet.
73 OM
de n8zu

Yup somebody gave me a stainless four section container which appears
to be unused and from an old fashioned ice-cream parlour/soda
fountain. There is also a single container, same depth and height etc.
And there is a nice rim around the open ends to which a front panel
could fastened!
Immediately thought of ready-made small equipment cabinets!
Scrapping a bunch of old microwaves is what raised the question of a
reuse for the cabinets. We had a school cafeteria operation one time
with three or four m.waves in use for short periods, on several
occasions was able to scrap older ones for parts for repairs. Now just
junk lying around!


I saw one at a hamfest in the tailgate section someone was trying to
sell that was turned into a HV power supply and it used a pair of
microwave oven transformers.

Jimmie


Instead of the 1 KV power supply at 1 Amp, there's the possibility of
bandsawing off the high voltage winding all together, and winding on 5
or 6 turns of welding cable. This makes a useful spot welder for
stainless steel sheet, which material performs specially well with spot
welds.
The power is low end so its important to choose a microwave rated at
least 1100 watts for this makeover.

Brian W

stan July 22nd 09 12:36 AM

Use old microwave cabinets?
 
On Jul 18, 6:57*pm, brian whatcott wrote:
JIMMIE wrote:
On Jul 15, 10:52 pm, stan wrote:
On Jul 13, 1:02 am, raypsi wrote:


Hey OM:
Microwave ovens are built for a price, the cheaper the better. The
Chinese have a lot of crap out there. Even the fans are junk. I mean
who uses a shaded pole syncro motor for a fan these days, power hungry
junk. Best you could get out of a microwave oven is the metal cabinet
can be cut up with scissors, that's right, dollar store scissors, will
cut the sheet metal they use on microwave ovens. And with a good brake
you can make a lot of project boxes.
Well stainless steel project boxes would look sweet.
73 OM
de n8zu
Yup somebody gave me a stainless four section container which appears
to be unused and from an old fashioned ice-cream parlour/soda
fountain. There is also a single container, same depth and height etc.
And there is a nice rim around the open ends to which a front panel
could fastened!
Immediately thought of ready-made small equipment cabinets!
Scrapping a bunch of old microwaves is what raised the question of a
reuse for the cabinets. We had a school cafeteria operation one time
with three or four m.waves in use for short periods, on several
occasions was able to scrap older ones for parts for repairs. Now just
junk lying around!


I saw one at a hamfest in the tailgate section someone was trying to
sell that was turned into a HV power supply and it used a pair of
microwave oven transformers.


Jimmie


Instead *of the 1 KV power supply at 1 Amp, there's the possibility of
bandsawing off the high voltage winding all together, and winding on 5
or 6 turns of welding cable. * This makes a useful spot welder for
stainless steel sheet, which material performs specially well with spot
welds.
The power is low end so its important to choose a microwave rated at
least 1100 watts for this makeover.

Brian W- Hide quoted text -

- Show quoted text -


Same technique (cutting off HV winding and putting a few turns to make
a battery charger transformer was also mentioned.
And previously had mentioned that HV winding to 115 volt mains winding
was a turns/voltage ratio of approx 20:1.
Hence an impedance matching ratio of 400 to one! Might be good enough
to match an 8 ohm speaker load into say a triode connected power tube?
400 x 8 = 3200? Haven't tried it! Just rambling around. Hate to throw
stuff away.


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