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#1
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Does anyone in the group know anything about magnetrons? I planning to
do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert |
#2
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Try looking up "injection locking". Basically, you take a stable signal
and force it into the magnetron via a directional coupler or isolator. The magnetron synchs with that signal. Multiple magnetrons might synch to each other depending on the coupling between them. Maintaining proper phase might still be an issue for the combiner method. Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
#3
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Ok I will look into injection locking.
Thanks, Bert On Jan 15, 12:14*am, **THE-RFI-EMI-GUY** wrote: Try looking up "injection locking". Basically, you take a stable signal and force it into the magnetron via a directional coupler or isolator. The magnetron synchs with that signal. Multiple magnetrons might synch to each other depending on the coupling between them. Maintaining proper phase might still be an issue for the combiner method. Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" *;-P |
#4
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You will probably have to add "magnetron " to your search terms.
Bert wrote: Ok I will look into injection locking. Thanks, Bert On Jan 15, 12:14 am, **THE-RFI-EMI-GUY** wrote: Try looking up "injection locking". Basically, you take a stable signal and force it into the magnetron via a directional coupler or isolator. The magnetron synchs with that signal. Multiple magnetrons might synch to each other depending on the coupling between them. Maintaining proper phase might still be an issue for the combiner method. Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
#5
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One microwave oven magnetron will get you pretty close to the legal
limit. They can be injection locked together, but that usually requires a circulator that can handle the necessary power (big $). You also need some way of adjusting the phase between the magnetrons so that the power will add. The adjustment can be tricky as they will tend to interact even with the circulators. 73, Erich N6FD Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert |
#6
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Show how much are circulators?. For the phase can I add an adjustable
delay? Again Thanks, Bert On Jan 15, 11:07*pm, Erich wrote: One microwave oven magnetron will get you pretty close to the legal limit. *They can be injection locked together, but that usually requires a circulator that can handle the necessary power (big $). *You also need some way of adjusting the phase between the magnetrons so that the power will add. *The adjustment can be tricky as they will tend to interact even with the circulators. 73, Erich N6FD Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert- Hide quoted text - - Show quoted text - |
#7
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Circulators are pretty pricy. You will need at least one to keep the
high power energy from each magnetron from getting back into the injection source. I read somewhere that about 2% of the magnetron power is required to injection lock. As far as phase, you will need a mechanical or electrical means to adjust the phase of the legs of the injection signals as well as a means to adjust the phase of the magnetrons when combining them. Typically a peice of coax or waveguide of some fraction of a wavelength as require IE; 1/4 wave = 90 degrees. Coax has a velocity factor which makes it behave electrically longer than it is physically. I am guessing, but perhaps with proper coupling technique, you might get the magnetrons to lock to each other coherently. Bert wrote: Show how much are circulators?. For the phase can I add an adjustable delay? Again Thanks, Bert On Jan 15, 11:07 pm, Erich wrote: One microwave oven magnetron will get you pretty close to the legal limit. They can be injection locked together, but that usually requires a circulator that can handle the necessary power (big $). You also need some way of adjusting the phase between the magnetrons so that the power will add. The adjustment can be tricky as they will tend to interact even with the circulators. 73, Erich N6FD Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert- Hide quoted text - - Show quoted text - -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
#8
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Hi Joe,
Thank you the info. Is it required to cross couple them, or can I use one magnetron as a "master" that injects into 3 to 5 other "slave" magnetrons? I will post the results of my effort. Again thanks. Cheers, Bert On Jan 17, 12:24*am, **THE-RFI-EMI-GUY** wrote: Circulators are pretty pricy. You will need at least one to keep the high power energy from each magnetron from getting back into the injection source. I read somewhere that about 2% of the magnetron power is required to injection lock. As far as phase, you will need a mechanical or electrical means to adjust the phase of the legs of the injection signals as well as a means to adjust the phase of the magnetrons when combining them. Typically a peice of coax or waveguide of some fraction of a wavelength as require IE; 1/4 wave = 90 degrees. Coax has a velocity factor which makes it behave electrically longer than it is physically. I am guessing, but perhaps with proper coupling technique, you might get the magnetrons to lock to each other coherently. Bert wrote: Show how much are circulators?. For the phase can I add an adjustable delay? Again Thanks, Bert On Jan 15, 11:07 pm, Erich wrote: One microwave oven magnetron will get you pretty close to the legal limit. *They can be injection locked together, but that usually requires a circulator that can handle the necessary power (big $). *You also need some way of adjusting the phase between the magnetrons so that the power will add. *The adjustment can be tricky as they will tend to interact even with the circulators. 73, Erich N6FD Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert- Hide quoted text - - Show quoted text - -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" *;-P- Hide quoted text - - Show quoted text - |
#9
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![]() Bert wrote: Hi Joe, Thank you the info. Is it required to cross couple them, or can I use one magnetron as a "master" that injects into 3 to 5 other "slave" magnetrons? I will post the results of my effort. Again thanks. Cheers, Bert On Jan 17, 12:24 am, **THE-RFI-EMI-GUY** wrote: Circulators are pretty pricy. You will need at least one to keep the high power energy from each magnetron from getting back into the injection source. I read somewhere that about 2% of the magnetron power is required to injection lock. As far as phase, you will need a mechanical or electrical means to adjust the phase of the legs of the injection signals as well as a means to adjust the phase of the magnetrons when combining them. Typically a peice of coax or waveguide of some fraction of a wavelength as require IE; 1/4 wave = 90 degrees. Coax has a velocity factor which makes it behave electrically longer than it is physically. I am guessing, but perhaps with proper coupling technique, you might get the magnetrons to lock to each other coherently. Bert wrote: Show how much are circulators?. For the phase can I add an adjustable delay? Again Thanks, Bert On Jan 15, 11:07 pm, Erich wrote: One microwave oven magnetron will get you pretty close to the legal limit. They can be injection locked together, but that usually requires a circulator that can handle the necessary power (big $). You also need some way of adjusting the phase between the magnetrons so that the power will add. The adjustment can be tricky as they will tend to interact even with the circulators. 73, Erich N6FD Bert wrote: Does anyone in the group know anything about magnetrons? I planning to do some experiments in transmitting microwaves. I would like to use standard magnetrons from a microwave oven and believe I can beam further if operated at the same frequency and with the outputs in phase. I have no idea on how to do this. Please advise Cheers, Bert- Hide quoted text - - Show quoted text - -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P- Hide quoted text - - Show quoted text - Its only going to be as stable as the master. There is also some discussion about the Q of the cavity. If the Q is too high, the ability to "pull" the frequency will be restricted. I am afraid you are playing in the sandbox of experimentation. Best of luck and don't fry yourself! -- Joe Leikhim K4SAT "The RFI-EMI-GUY"© "Treason doth never prosper: what's the reason? For if it prosper, none dare call it treason." "Follow The Money" ;-P |
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