Any suggestions on how to build a 2.4 GHz CW transmitter with a microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV transformer
with a pair of HV rectifiers to feed alternate cycles to the magnetrons?

Greg, VE0ACR

Anchor wrote:

Any suggestions on how to build a 2.4 GHz CW transmitter with a microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV transformer
with a pair of HV rectifiers to feed alternate cycles to the magnetrons?

Greg, VE0ACR

The July 1989 73 had an article on using a microwave oven for ATV. It
involved keeping most of the oven intact (including interlocks), with a
blocking plate over the opening between the magnetron and the oven
cavity and an e-field probe to couple the output to coax.

Beyond that I know nothing.

--
-------------------------------------------
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Here is one guy which considers "weaponizing" one, perhaps there is data
there you can use...
http://www.nettwerked.net/EM-HERF_Weapons_p1.txt

There used to be a webpage which showed, in quite some detail, one
hooked up to a hornfeed and used to attack neighbors in a new york
apartment... I can't find it now... the picture detail was excellent
though--had thought of constructing one to goof around with back then...

Warmest regards,
John

"Anchor" wrote in message
news
Any suggestions on how to build a 2.4 GHz CW transmitter with a
microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the
web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee
can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray
RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV
transformer
with a pair of HV rectifiers to feed alternate cycles to the
magnetrons?

Greg, VE0ACR

a pringle 'can' would probably arc and burn up. i would really worry about
side/rear lobes with coffee can antennas, even a minor lobe when working
with kw levels at those frequencies could do some real damage in a short
time... and reflections off nearby objects of the main lobe could really do
a job on you. remember what those things are meant to do and be darn sure
you don't end up looking like a bag of popcorn.

"Anchor" wrote in message
news
Any suggestions on how to build a 2.4 GHz CW transmitter with a microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV transformer
with a pair of HV rectifiers to feed alternate cycles to the magnetrons?

Greg, VE0ACR

On Sun, 12 Jun 2005 17:39:36 -0700, John Smith wrote:

Here is one guy which considers "weaponizing" one, perhaps there is data
there you can use...
http://www.nettwerked.net/EM-HERF_Weapons_p1.txt

There used to be a webpage which showed, in quite some detail, one
hooked up to a hornfeed and used to attack neighbors in a new york
apartment... I can't find it now... the picture detail was excellent
though--had thought of constructing one to goof around with back then...

Warmest regards,
John

That web site is a joke, isn't it???

"Anchor" wrote in message
news
Any suggestions on how to build a 2.4 GHz CW transmitter with a microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV transformer
with a pair of HV rectifiers to feed alternate cycles to the magnetrons?

Greg, VE0ACR

I once looked at a microwave oven on a spectrum analyzer (Loosely coupled
near the door seal). The signal was spread over 100s of MHz. It also
appeared to be pulsed. The spectrum, however, did not look like the
expected
Sa(x) distribution. Magnetrons are not noted for their stability, and are
probably not suitable for CW. I have played with tunable 500 mW klystrons,
and they can drift 10s of MHz (at 12 GHz), in a very short period of time.

73,

Frank

Frank wrote:

snip


I once looked at a microwave oven on a spectrum analyzer (Loosely coupled
near the door seal). The signal was spread over 100s of MHz. It also
appeared to be pulsed. The spectrum, however, did not look like the
expected
Sa(x) distribution. Magnetrons are not noted for their stability, and are
probably not suitable for CW. I have played with tunable 500 mW klystrons,
and they can drift 10s of MHz (at 12 GHz), in a very short period of time.

73,

Frank


In the article I quoted above they tune the magnetron frequency by
varying the voltage to the magnetron. I wouldn't be surprised if the
oven's DC to the magnetron was filtered lightly or not at all.

--
-------------------------------------------
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I would think a 1KW or greater magnetron run off a non-filtered and
particularly dirty, but rectified dc supply (you could even feed a ramp
or triangle dc power wave to the magnetron to cause frequency sweep) and
into a sloppy waveguide exhibiting multiple resonant frequencies would
knock out all cell phone and wireless communications on shf+ freqs for
blocks if not miles... you would probably start jamming the cell towers
for miles around and have every "pirate transmitter" hunter in America
on your tail... in a large city/metro area you would cause havoc to
break out--this WOULD BE ONE SERIOUS OFFENSE!!! If caught, you would
learn to call prison your home!

And Bruce, in the cell next to you, would fall in love with you!

Not to mention the danger of exposure to the freqs in question--this
would be best left alone...

John

"Anchor" wrote in message
news
Any suggestions on how to build a 2.4 GHz CW transmitter with a
microwave
oven magnetron and a 2.4 GHz "pringle" or coffee can style antenna?

There are tons of "pringle" or coffee can antennas or similar on the
web.
For example: http://flakey.info/antenna/waveguide or
http://www.turnpoint.net/wireless/an...coffeecan.html

I suppose one need only insert the magnetron antenna into the coffee
can
where one would normally mount the N-connector feed point.

A labeled diagram of a microwave magnetron can be found at:
http://www.gallawa.com/microtech/mag_test.html

I suppose the metal coffee can has superior micro shielding properties
relative to the aluminumized cardboard pringle can.

Would I be better off with plumbing copper drain pipe from the stray
RF
exposure perspective?

Since microwave magnetron use a half wave power supply, can I use two
magnetrons in the same coffee can powered from a single AC HV
transformer
with a pair of HV rectifiers to feed alternate cycles to the
magnetrons?

Greg, VE0ACR

"John Smith" wrote in message
news
I would think a 1KW or greater magnetron run off a non-filtered and
particularly dirty, but rectified dc supply (you could even feed a ramp or
triangle dc power wave to the magnetron to cause frequency sweep) and into
a sloppy waveguide exhibiting multiple resonant frequencies would knock out
all cell phone and wireless communications on shf+ freqs for blocks if not
miles... you would probably start jamming the cell towers for miles around
and have every "pirate transmitter" hunter in America on your tail... in a
large city/metro area you would cause havoc to break out--this WOULD BE ONE
SERIOUS OFFENSE!!! If caught, you would learn to call prison your home!

And Bruce, in the cell next to you, would fall in love with you!

Not to mention the danger of exposure to the freqs in question--this would
be best left alone...

Interesting paper concerning microwave magnetrons at
http://www-personal.engin.umich.edu/...laes_tps04.pdf

Mention is made of magnetron cavity Qs in excess of 200. The spectral width
of such a source, at the 3 dB points, would therefore be about 12 MHz. Not
really suitable for CW, but far better than my observations. Comments about
poor power supplies are probably correct.

It is interesting to note that the spectral purity of oven magnetrons is of
concern with regards to interference to the 2.4 GHz ISM band.

There are techniques for the stabilization of magnetrons when used for
Moving Target Indication (MTI) on RADAR systems.

The fact is it is very easy to build a high stability synthesizer -- with
spectral widths of the order of 1 or 2 Hz -- at 2.4 GHz. Amplification is
another matter, since a 2.4 GHz TWT probably costs around $7,000.

73,

Frank

In article ,
"John Smith" wrote:

I would think a 1KW or greater magnetron run off a non-filtered and
particularly dirty, but rectified dc supply (you could even feed a ramp
or triangle dc power wave to the magnetron to cause frequency sweep) and
into a sloppy waveguide exhibiting multiple resonant frequencies would
knock out all cell phone and wireless communications on shf+ freqs for
blocks if not miles... you would probably start jamming the cell towers
for miles around and have every "pirate transmitter" hunter in America
on your tail... in a large city/metro area you would cause havoc to
break out--this WOULD BE ONE SERIOUS OFFENSE!!! If caught, you would
learn to call prison your home!

And Bruce, in the cell next to you, would fall in love with you!

Not to mention the danger of exposure to the freqs in question--this
would be best left alone...

John

Bull****, a 2.4 Ghz Magnitron would NOT cause any problems for any 800
Mhz or even any 1.8 Ghz cellphone system no matter how bad the
powersupply was filtered. This just doesn't COMPUTE, even in another
world, lifetime, or dimension.


Me