Arfa Daily wrote:
"Richard G. Gould" wrote in message
...
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


The waveguide on the output of the mag (and it is a mag - ignore what
clodhopper says below about it being a klystron) can become coated with
resolidified vapourised grease and clag from the food that's been cooked in
it - especially if it is a combination type that has a conventional oven in
it as well. This can result in substantially reduced microwave cooking
efficiency.

Absobloominglutely

The first thing to do with an oven which appears to have lost
perfomance, is to give the cavity a good clean, including the inside
glass of the door and the waveguide cover and to check that there`s no
nasty carbonised gunk up the waveguide. Simply replacing the waveguide
cover perks them up a bit.

It`s also important to check the spade connectors on the magnetron,
these sometimes become loose and erode away making intermittent contact
for the heater current. My own Panasonic was suffering from this - about
one in four cookings would fail, replacing the spade connectors cured
the problem.

It is possible (IME) for magnetrons to lose power over time, sometimes
the antenna cap gets eroded away and sometimes you find cracks in one of
the magnets.

Ron