Usual failure modes of magnetrons?

On Jan 9, 11:16 pm, Winston <Wins...@BigBrother.net> wrote:





hrhofm...@att.net wrote:

(...)

Every one I have ever salvaged had low magnetron output or a bad HV
transformer.  Never seen a cracked magnet.  But those old magnets are
great for fooling around with as they ar so strong.

I wonder if a cracked magnet could cause low microwave
output?

Sounds like a chicken and egg problem.
Excessive power dissipation in the magnetron might
cause a magnet to crack. (Line transient perhaps?)
The cracked magnet would push the magnetron
away from cutoff, forcing it to dissipate more
power which heats the magnets, etc.

--Winston

Like you we have a small Goldstar oven that we got as an incentive for
visiting a time share back around 1985. The thing has a simple wind up
clock timer that rings a bell when it runs down. It too has worked
flawlessly all these years. I've been repairing consumer electronics
all my life and although I've never heard the term before I firmly
believe that "crap engineering"  is in everything today and is
definitely alive and well in China. Lenny

On Jan 10, 7:29 am, klem kedidelhopper <captainvideo462...@gmail.com
wrote:



On Jan 9, 11:16 pm, Winston <Wins...@BigBrother.net> wrote:

hrhofm...@att.net wrote:

(...)

Every one I have ever salvaged had low magnetron output or a bad HV
transformer.  Never seen a cracked magnet.  But those old magnets are
great for fooling around with as they ar so strong.

I wonder if a cracked magnet could cause low microwave
output?

Sounds like a chicken and egg problem.
Excessive power dissipation in the magnetron might
cause a magnet to crack. (Line transient perhaps?)
The cracked magnet would push the magnetron
away from cutoff, forcing it to dissipate more
power which heats the magnets, etc.

--Winston

Like you we have a small Goldstar oven that we got as an incentive for
visiting a time share back around 1985. The thing has a simple wind up
clock timer that rings a bell when it runs down. It too has worked
flawlessly all these years. I've been repairing consumer electronics
all my life and although I've never heard the term before I firmly
believe that "crap engineering"  is in everything today and is
definitely alive and well in China. Lenny

I'm old enough to remember when we used to pick up a 'broken' item and
pretend to read a label on it, musing out loud, "Oh, I see what's
wrong. MADE IN JAPAN." ThenJapan got their act together and became one
of the best suppliers of high quality opticselectronics/musical
instruments.

So, ...the lesson? it is apparently far easier to continue to make
things cheap, but learn how to make them well rather than continue to
make things well, but learn how to make them cheap.  Shudder

On Jan 10, 10:37 am, Robert Macy <robert.a.m...@gmail.com> wrote:





On Jan 10, 7:29 am, klem kedidelhopper <captainvideo462...@gmail.com
wrote:

On Jan 9, 11:16 pm, Winston <Wins...@BigBrother.net> wrote:

hrhofm...@att.net wrote:

(...)

Every one I have ever salvaged had low magnetron output or a bad HV
transformer.  Never seen a cracked magnet.  But those old magnets are
great for fooling around with as they ar so strong.

I wonder if a cracked magnet could cause low microwave
output?

Sounds like a chicken and egg problem.
Excessive power dissipation in the magnetron might
cause a magnet to crack. (Line transient perhaps?)
The cracked magnet would push the magnetron
away from cutoff, forcing it to dissipate more
power which heats the magnets, etc.

--Winston

Like you we have a small Goldstar oven that we got as an incentive for
visiting a time share back around 1985. The thing has a simple wind up
clock timer that rings a bell when it runs down. It too has worked
flawlessly all these years. I've been repairing consumer electronics
all my life and although I've never heard the term before I firmly
believe that "crap engineering"  is in everything today and is
definitely alive and well in China. Lenny

I'm old enough to remember when we used to pick up a 'broken' item and
pretend to read a label on it, musing out loud, "Oh, I see what's
wrong. MADE IN JAPAN." ThenJapan got their act together and became one
of the best suppliers of high quality opticselectronics/musical
instruments.

So, ...the lesson? it is apparently far easier to continue to make
things cheap, but learn how to make them well rather than continue to
make things well, but learn how to make them cheap.  Shudder

So the "lesson" is: don't throw out your old stuff. Maintain it as
long as you can because, (and sadly), "they just don't make em like
that any more".....Lenny

On Jan 9, 11:16 pm, Winston <Wins...@BigBrother.net> wrote:
hrhofm...@att.net wrote:

(...)

Every one I have ever salvaged had low magnetron output or a bad HV
transformer.  Never seen a cracked magnet.  But those old magnets are
great for fooling around with as they ar so strong.

I wonder if a cracked magnet could cause low microwave
output?

Sounds like a chicken and egg problem.
Excessive power dissipation in the magnetron might
cause a magnet to crack. (Line transient perhaps?)
The cracked magnet would push the magnetron
away from cutoff, forcing it to dissipate more
power which heats the magnets, etc.

--Winston

Like you we have a small Goldstar oven that we got as an incentive for
visiting a time share back around 1985. The thing has a simple wind up
clock timer that rings a bell when it runs down. It too has worked
flawlessly all these years. I've been repairing consumer electronics
all my life and although I've never heard the term before I firmly
believe that "crap engineering" is in everything today and is
definitely alive and well in China. Lenny