Microwave oven

[Richard G. Gould]

It appears that our microwave oven has lost cooking/heating power over the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by heating
a known quantity of water to a desired rise in temperature over a prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

Rick

 

[Meat Plow]

On Sun, 19 Oct 2008 02:22:41 GMT, "Richard G. Gould"
<rickgould@verizon.net>wrote:

It appears that our microwave oven has lost cooking/heating power over the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by heating
a known quantity of water to a desired rise in temperature over a prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

Rick

Magnetrons do lose their output over time.

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

 

[Franc Zabkar]

On Sun, 19 Oct 2008 02:22:41 GMT, "Richard G. Gould"
<rickgould@verizon.net> put finger to keyboard and composed:

It appears that our microwave oven has lost cooking/heating power over the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by heating
a known quantity of water to a desired rise in temperature over a prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

Rick

Notes on the Troubleshooting and Repair of Microwave Ovens

7.1) Testing the oven - the water heating test:
http://www.repairfaq.org/REPAIR/F_micfaq4.html#MICFAQ_017

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Claude Hopper]

Richard G. Gould wrote:

It appears that our microwave oven has lost cooking/heating power over the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by heating
a known quantity of water to a desired rise in temperature over a prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

Rick


It's not a magnetron, it's a klystron. It's a tube and tubes get weak.

But more likely, one of the power sources has become weak.

Three power sources are required for reflex klystron operation: (1)
filament power, (2) positive resonator voltage (often referred to as
beam voltage) used to accelerate the electrons through the grid gap of
the resonant cavity, and (3) negative repeller voltage used to turn the
electron beam around. The electrons are focused into a beam by the
electrostatic fields set up by the resonator potential (B+) in the body
of the tube.

 

[William Sommerwerck]

It appears that our microwave oven has lost cooking/heating power over
the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by
heating
a known quantity of water to a desired rise in temperature over a
prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

It's not a magnetron, it's a klystron. It's a tube and tubes get weak.
But more likely, one of the power sources has become weak.

I don't know where you get your information, but microwave ovens use
magentrons. A klystron is a rather different sort of microwave device. For
one thing, it's an amplifier, not an oscillator (unless you misalign it,
especially the B cavity).

I know about these things, because I used to install and align klystrons. I
could tell you a few "Jedi tricks".

 

[nobody >]

William Sommerwerck wrote:

It appears that our microwave oven has lost cooking/heating power over
the
years. Is that possible: Can the magnetron put out less power as it ages?
How can one test the heating power of a microwave oven: Perhaps by
heating
a known quantity of water to a desired rise in temperature over a
prescribed
time period? Are there any such measures for a microwave oven of a known
original/rated power?

It's not a magnetron, it's a klystron. It's a tube and tubes get weak.
But more likely, one of the power sources has become weak.

I don't know where you get your information, but microwave ovens use
magentrons. A klystron is a rather different sort of microwave device. For
one thing, it's an amplifier, not an oscillator (unless you misalign it,
especially the B cavity).

I know about these things, because I used to install and align klystrons. I
could tell you a few "Jedi tricks".

.....Just remembering a few years of tweaking 1kw klys'es at 0-dark-30 in
the military and watching the beam current like a hawk.....


ISTR some commercial process heating chambers that used multiple
klystrons for outputs.