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The Magnetron - A Low Noise, Long Life Amplifier????
The Magnetron - A Low Noise, Long Life Amplifier????
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Old 20th January 2011, 08:26 PM   #11
Tubelab_com is offline Tubelab_com  United States
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The frequency mentioned here, 2.4GHz, is right in the middle of aviation frequencies.
The frequency of operation of all microwave ovens is 2.45GHz +/- 50 MHz. This is in the ISM (industrial scientific medical) band for that reason. A leaky microwave oven will not cause interference to any licensed service except amateur radio since many ham radio bands are coincident with ISM bands. 902 -928 MHz and 2304 - 2450 MHz are examples.

there is somwhere on the web a guy that built one of those magnatron RF amplifiers and then connected it to a 30 db parabolic dish if i remmember it only had a beamwidth of 8 degrees. WOW!!!!.
This practice isn't too uncommon amongst EME (amateur radio moonbounce) guys. There was an article published in a ham radio magazine (QST maybe) in the mid 1980's that showed how to control the frequency of oscillation of a magnetron and achieve FM modulation. I built that setup (using two 6JE6C's to control magnetron current) and got it to work. I installed the magnetron into a coffee can feedhorn and mounted it in front of a 12 foot TV satellite dish. Attempts to bounce a signal off of the moon were not successful. I now understand that the bandwith of an FM signal was far too wide for that type of communication. I still have the magnetron device somewhere. Magnetrons operate in the 2KV+ range. Don't even think of opening a microwave oven unless you understand the voltages involved.

It is now possible to find surplus cellular equipment for use in this frequency range and 200 watts at 2304 MHz is available on Ebay. I am building a 1200 watt station for 902 MHz using surplus cellular equipment.
Tubelab, it's 5 year mission. To explore strange new tubes, to seek out new circuits and topologies, to boldly go where no tube has gone before......
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Old 21st January 2011, 07:30 AM   #12
Richard Ellis is offline Richard Ellis  Argentina
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Oh yeah I know that thing!!..............My instructor in Microwaves...An ex-Air-Force guy told me of him & his buddies goofing with the on-base Radar systems....They took one of the giant dishes, took it off-line swung it around, pointed it down to the ground & lit up some flourescent lights in an office several hundred feet away. Fun, fun, fun.........

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Old 21st January 2011, 07:39 AM   #13
RTF671 is offline RTF671  United States
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You could also jam your roommate's wifi, if you don't mind not having any either.
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Old 21st January 2011, 08:10 AM   #14
madtecchy is offline madtecchy  England
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Watch out for those microwaves 2.4gHz just happens to be the resonant frequency of water. Also if you are thinking of starting a family in the future extra wow is required.
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Old 21st January 2011, 12:20 PM   #15
DF96 is offline DF96  England
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It is also possible to cook other spherical objects, namely your eyes. I understand that when cooked, the transparent bits turn white like an egg does. Permanent blindness is the result. Don't mess with high power microwaves!
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