AM Microwave Oven Klystron

[ChrisQ]

Phil Allison wrote:

"Chris Quack"


** Kindly drop dead ..........

Fuckwit.




.... Phil

You were doing quite well with your previous post. A bit of technology
explained with an enlightening reply. Asked a simple additional question
and we get the above ?.

Another bipolar episode ?, or do you assume that everyone's being
sarcastic all the time ?...

Regards,

Chris

 

[Phil Allison]

"Chris Quack"



** DROP FUCKING dead !!!!!!!!!

You stinking fuckwit TROLL





.... Phil

 

[MooseFET]

On Nov 27, 10:43 am, Spehro Pefhany
<speffS...@interlogDOTyou.knowwhat> wrote:

On Fri, 27 Nov 2009 08:28:57 -0800 (PST), MooseFET



kensm...@rahul.net> wrote:
On Nov 26, 6:22 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat
wrote:
On Thu, 26 Nov 2009 17:35:27 -0800 (PST), the renowned

a7yvm109gf...@netzero.com wrote:
On Nov 26, 7:35 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Brent Steven"

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

** The RF output is already modulated  -  at 50Hz.

...  Phil

..or 60Hz. Or is it double?

Phil is likely right, and it's 50Hz (since the OP appears to be in
Sydney Australia). Magnetron ovens magnetrons are usually powered via
an unfiltered half-wave doubler, with or without a high frequency
chopper.

HOWEVER, if it's a modern type such as Panasonic inverter type, it may
be seeing a more steady voltage across the magnetron.

I think the inverter ones don't filter the rectified mains (at least
not very much).  There would likely be a large modulation at twice the
mains.  At least this is how the EMI from it sounds on a nearby radio.

Here's one schematic that would fall into the "not very much"
category:-

http://www.eletrodomesticosforum.com/downloads/microondas/Panasonic_N...

(page 20).

It is surprising that they need that many discrete parts. The product
is mass produced so cutting down on the parts count would be very
worth it.

 

[JosephKK]

On Fri, 27 Nov 2009 13:43:08 -0500, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Fri, 27 Nov 2009 08:28:57 -0800 (PST), MooseFET
kensmith@rahul.net> wrote:

On Nov 26, 6:22 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat
wrote:
On Thu, 26 Nov 2009 17:35:27 -0800 (PST), the renowned



a7yvm109gf...@netzero.com wrote:
On Nov 26, 7:35 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Brent Steven"

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

** The RF output is already modulated  -  at 50Hz.

...  Phil

..or 60Hz. Or is it double?

Phil is likely right, and it's 50Hz (since the OP appears to be in
Sydney Australia). Magnetron ovens magnetrons are usually powered via
an unfiltered half-wave doubler, with or without a high frequency
chopper.

HOWEVER, if it's a modern type such as Panasonic inverter type, it may
be seeing a more steady voltage across the magnetron.

I think the inverter ones don't filter the rectified mains (at least
not very much). There would likely be a large modulation at twice the
mains. At least this is how the EMI from it sounds on a nearby radio.

Here's one schematic that would fall into the "not very much"
category:-

http://www.eletrodomesticosforum.com/downloads/microondas/Panasonic_NN-G62BH.pdf

(page 20).

I would expect that one to splatter at a much higher fundamental
frequency, like 30 kHz. That high power transformer feeing the
doubler is not operating at 50 or 60 Hz.

 

[JosephKK]

On Fri, 27 Nov 2009 13:42:05 -0800 (PST), "nuny@bid.nes"
<alien8752@gmail.com> wrote:

On Nov 26, 4:07 pm, brentstev...@radgrah.com (Brent Steven) wrote:
To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

Of course, any work will be done at our own risk by our own
techncians.

If you for some reason can't use a klystron (all you can afford is a
magnetron, frinst), consider removing the magnetron's permanent
magnets and winding coils to provide the magnetic field; you can then
modulate their current. This basically takes the tube in and out of
resonance, raising and dropping the output power. Slightly easier to
modulate high current/low voltage than the other way around.

Just a thought.


Mark L. Fergerson

So long as you stay within B limits you can FM a maggie nicely that
way. Going outside the limits tends to OOK it.

 

[John Larkin]

On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent
Steven) wrote:

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

Of course, any work will be done at our own risk by our own
techncians.

Thank you,

Brent Stevens
TechPro Group

Magnetron, not klystron.

John

 

[MooseFET]

On Dec 3, 10:53 pm, "JosephKK"<quiettechb...@yahoo.com> wrote:

On Fri, 27 Nov 2009 13:43:08 -0500, Spehro Pefhany



speffS...@interlogDOTyou.knowwhat> wrote:
On Fri, 27 Nov 2009 08:28:57 -0800 (PST), MooseFET
kensm...@rahul.net> wrote:

On Nov 26, 6:22 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat
wrote:
On Thu, 26 Nov 2009 17:35:27 -0800 (PST), the renowned

a7yvm109gf...@netzero.com wrote:
On Nov 26, 7:35 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Brent Steven"

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

** The RF output is already modulated  -  at 50Hz.

...  Phil

..or 60Hz. Or is it double?

Phil is likely right, and it's 50Hz (since the OP appears to be in
Sydney Australia). Magnetron ovens magnetrons are usually powered via
an unfiltered half-wave doubler, with or without a high frequency
chopper.

HOWEVER, if it's a modern type such as Panasonic inverter type, it may
be seeing a more steady voltage across the magnetron.

I think the inverter ones don't filter the rectified mains (at least
not very much).  There would likely be a large modulation at twice the
mains.  At least this is how the EMI from it sounds on a nearby radio..

Here's one schematic that would fall into the "not very much"
category:-

http://www.eletrodomesticosforum.com/downloads/microondas/Panasonic_N...

(page 20).

I would expect that one to splatter at a much higher fundamental
frequency, like 30 kHz.  That high power transformer feeing the
doubler is not operating at 50 or 60 Hz.

The secondary side has enough filtering that I suspect that the
perhaps 30KHz won't be all that strong on the high voltage. There
isn't enough filtering that it would matter to the mains frequency
ripple. I doubt that a sandwich cares about the sidebands on the
microwaves much.

 

[Spehro Pefhany]

On Thu, 03 Dec 2009 22:53:09 -0800,
"JosephKK"<quiettechblue@yahoo.com> wrote:

On Fri, 27 Nov 2009 13:43:08 -0500, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Fri, 27 Nov 2009 08:28:57 -0800 (PST), MooseFET
kensmith@rahul.net> wrote:

On Nov 26, 6:22 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat
wrote:
On Thu, 26 Nov 2009 17:35:27 -0800 (PST), the renowned



a7yvm109gf...@netzero.com wrote:
On Nov 26, 7:35 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Brent Steven"

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

** The RF output is already modulated  -  at 50Hz.

...  Phil

..or 60Hz. Or is it double?

Phil is likely right, and it's 50Hz (since the OP appears to be in
Sydney Australia). Magnetron ovens magnetrons are usually powered via
an unfiltered half-wave doubler, with or without a high frequency
chopper.

HOWEVER, if it's a modern type such as Panasonic inverter type, it may
be seeing a more steady voltage across the magnetron.

I think the inverter ones don't filter the rectified mains (at least
not very much). There would likely be a large modulation at twice the
mains. At least this is how the EMI from it sounds on a nearby radio.

Here's one schematic that would fall into the "not very much"
category:-

http://www.eletrodomesticosforum.com/downloads/microondas/Panasonic_NN-G62BH.pdf

(page 20).



I would expect that one to splatter at a much higher fundamental
frequency, like 30 kHz. That high power transformer feeing the
doubler is not operating at 50 or 60 Hz.

It's modulated at line frequency because of almost total lack of input
filtering.

 

[Tim Williams]

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:sc9ih51954itp5srlg4rhl70jc28peung0@4ax.com...

Magnetron, not klystron.

Someone said frequency modulation somewhere. I have some small reflex
klystrons... trivial. ;-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

 

[John Larkin]

On Fri, 4 Dec 2009 10:41:52 -0600, "Tim Williams"
<tmoranwms@charter.net> wrote:

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:sc9ih51954itp5srlg4rhl70jc28peung0@4ax.com...
Magnetron, not klystron.

Someone said frequency modulation somewhere. I have some small reflex
klystrons... trivial. ;-)

Tim

Good book: The Inventor and the Pilot, the story of the Varian
brothers, as told by Russel's widow.

John

 

[Rich Grise]

On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:

On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for a
one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

Cheers!
Rich

 

[Rich Grise]

On Fri, 04 Dec 2009 08:51:35 -0800, John Larkin wrote:

On Fri, 4 Dec 2009 10:41:52 -0600, "Tim Williams" <tmoranwms@charter.net
"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
message news:sc9ih51954itp5srlg4rhl70jc28peung0@4ax.com...
Magnetron, not klystron.

Someone said frequency modulation somewhere. I have some small reflex
klystrons... trivial. ;-)

Good book: The Inventor and the Pilot, the story of the Varian brothers,
as told by Russel's widow.

Backward Wave Oscillators (BWOs) are awesome in this respect, but probably
cost in the multi-kilobuck range. You can adjust the power output, center
frequency, modulation depth, _type_ of modulation (AM, FM, pulse) with a
few trimpots. I did this in the USAF, as an "Electronic Countermeasures"
tech.

Cheers!
Rich

 

[John Larkin]

On Fri, 04 Dec 2009 09:47:27 -0800, Rich Grise <richgrise@example.net>
wrote:

On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:
On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for a
one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

Cheers!
Rich

I don't know of any microwave ovens that use traveling-wave tubes.

John

 

[Rich Grise]

On Fri, 04 Dec 2009 11:11:05 -0800, John Larkin wrote:

On Fri, 04 Dec 2009 09:47:27 -0800, Rich Grise <richgrise@example.net
On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:
On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent
Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

I don't know of any microwave ovens that use traveling-wave tubes.

At this point, hasn't the thread become womewhat of a flight of fancy
anyway? Or is it just me? ;-)

I've seen pics of power klystrons, and they're scary! ;-)

Cheers!
Rich

 

[John Larkin]

On Fri, 04 Dec 2009 12:13:12 -0800, Rich Grise <richgrise@example.net>
wrote:

On Fri, 04 Dec 2009 11:11:05 -0800, John Larkin wrote:
On Fri, 04 Dec 2009 09:47:27 -0800, Rich Grise <richgrise@example.net
On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:
On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent
Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

I don't know of any microwave ovens that use traveling-wave tubes.

At this point, hasn't the thread become womewhat of a flight of fancy
anyway? Or is it just me? ;-)

I've seen pics of power klystrons, and they're scary! ;-)

Cheers!
Rich

SLAC uses klystrons that are about as big as me. Two miles of them.

John

 

[Tim Williams]

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:rttih5tui01r3u6bpb256mveltl02rtb5m@4ax.com...

SLAC uses klystrons that are about as big as me. Two miles of them.

Why don't they use solid state yet?

Oh right, those pricier-than-gold GaN FETs you're so fond of...

....Just imagine two miles of them, with the covers off, glowing an eerie
blue. No one would ever go down there, they'd think it's all Cherenkov
radiation from the beam. ;-)

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

 

[Spehro Pefhany]

On Fri, 04 Dec 2009 11:11:05 -0800, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 04 Dec 2009 09:47:27 -0800, Rich Grise <richgrise@example.net
wrote:

On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:
On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for a
one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

Cheers!
Rich


I don't know of any microwave ovens that use traveling-wave tubes.

John

That's a "straight line", isn't it?

 

[Jan Panteltje]

On a sunny day (Fri, 04 Dec 2009 12:58:19 -0800) it happened John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in
<rttih5tui01r3u6bpb256mveltl02rtb5m@4ax.com>:

On Fri, 04 Dec 2009 12:13:12 -0800, Rich Grise <richgrise@example.net
wrote:

On Fri, 04 Dec 2009 11:11:05 -0800, John Larkin wrote:
On Fri, 04 Dec 2009 09:47:27 -0800, Rich Grise <richgrise@example.net
On Fri, 04 Dec 2009 07:07:29 -0800, John Larkin wrote:
On Fri, 27 Nov 2009 00:07:28 GMT, brentstevens@radgrah.com (Brent
Steven)

To conduct an experiment, we need to amplitude modulate the output of a
domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

Of course, any work will be done at our own risk by our own techncians.

Magnetron, not klystron.

Or a Traveling Wave Amplifier Tube (TWAT). ;-)
http://www.google.com/search?q=%22traveling+wave+amplifier+tube%22

I don't know of any microwave ovens that use traveling-wave tubes.

At this point, hasn't the thread become womewhat of a flight of fancy
anyway? Or is it just me? ;-)

I've seen pics of power klystrons, and they're scary! ;-)

Cheers!
Rich

SLAC uses klystrons that are about as big as me. Two miles of them.

John

Not only SLAC, I have stood next to one in Amsterdam too....
They used a crane to lift it, heater needed refurbishing IIRC.
Was told not to play with it...
hehe

 

[JosephKK]

On Fri, 04 Dec 2009 11:32:14 -0500, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

On Thu, 03 Dec 2009 22:53:09 -0800,
"JosephKK"<quiettechblue@yahoo.com> wrote:

On Fri, 27 Nov 2009 13:43:08 -0500, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> wrote:

On Fri, 27 Nov 2009 08:28:57 -0800 (PST), MooseFET
kensmith@rahul.net> wrote:

On Nov 26, 6:22 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat
wrote:
On Thu, 26 Nov 2009 17:35:27 -0800 (PST), the renowned



a7yvm109gf...@netzero.com wrote:
On Nov 26, 7:35 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
"Brent Steven"

To conduct an experiment, we need to amplitude modulate the output of
a domestic microwave oven at a continuous audio frequency.

Can anyone offer any suggestions on the best means to achieve this for
a one time use?

** The RF output is already modulated  -  at 50Hz.

...  Phil

..or 60Hz. Or is it double?

Phil is likely right, and it's 50Hz (since the OP appears to be in
Sydney Australia). Magnetron ovens magnetrons are usually powered via
an unfiltered half-wave doubler, with or without a high frequency
chopper.

HOWEVER, if it's a modern type such as Panasonic inverter type, it may
be seeing a more steady voltage across the magnetron.

I think the inverter ones don't filter the rectified mains (at least
not very much). There would likely be a large modulation at twice the
mains. At least this is how the EMI from it sounds on a nearby radio.

Here's one schematic that would fall into the "not very much"
category:-

http://www.eletrodomesticosforum.com/downloads/microondas/Panasonic_NN-G62BH.pdf

(page 20).



I would expect that one to splatter at a much higher fundamental
frequency, like 30 kHz. That high power transformer feeing the
doubler is not operating at 50 or 60 Hz.

It's modulated at line frequency because of almost total lack of input
filtering.

Um, yeah. That little inductor into a 470 uF cap ain't much at that
power level. Though it will have less than non-inverter (regular)
types. Saves a bunch on transformer iron and some on copper though.

 

[ChrisQ]

Spehro Pefhany wrote:

I don't know of any microwave ovens that use traveling-wave tubes.

John

That's a "straight line", isn't it?

twt are far too expensive and the wrong technology for something as
mundane as heating. Magnetrons are simpler devices, cheaper and probably
more rugged as well. I think klystrons are used in some tv transmitters
still, but they are a fair bit bigger than the old 50's 723 725 radar
local oscillators, which is how I remember klystrons. I had a watkins
johnson 1-2Ghz low noise twt amplifer at one stage. It was encased in a
cylinder around 4" dia x 12" long, had a very big magnet inside and
weighed around 15-20lbs. To set the thing up, there were 6 or more
trimpots under one of the end covers, which also housed a 115v line psu.
Never used it for anything much though, let alone tried to set the thing up.

Some early hp spectrum analysers used watkins johnson bwo's (backward
wave oscillators), as did their early sweepers, but replacement costs
were astronomical. I was quoted over 7k $ us for a replacement tube in
my old analyser circa 1980, but eventually solved the problem by
tweaking the dc heater supply on the bwo by 100mV or so . The hp bwo
was a black ali case around 2" square and around 6" long, with solder
tags at one end and n connector at the other. Sweep hv of around
1000-2000 volts produced a 2-4Ghz op to provide the first lo for the
analyser, with a 2Ghz 1st if and disk seal triode first if amplifier.
They really were quite a beautifull work of art, all diecast
construction at rf but seriously heavy. I think the rf section was
around 70lbs unpacked, with the smaller solid state if section around
20. I do remember the display being super fine line and pin sharp focus
across the whole trace. Just like the old valve tektronix scopes and far
better than many of the later models from the same vendors...

Regards,

Chris