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#1
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The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal.
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#2
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JIMMIE wrote:
The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal. Radio amateurs do this all the time. In most countries, for it to be legal you need a radio amateur license. Today it actually is not very difficult to receive moon bounce reflections, because we can make very sensitive receivers and detect signals that are below the noise, using a computer. However, to do that you need to transmit a signal at a very stable frequency, so that you know beforehand what will be coming back. A microwave oven magnetron cannot really do that. It transmits a big blob of RF at a woblling output frequency, rather than a well defined frequency. You also don't need that power, really. It is better to spend your effort on a good antenna, because it helps both during transmit and during receive, doubling the outcome of your effort. |
#3
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On Sat, 05 Jan 2013 04:02:59 -0800, JIMMIE wrote:
The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal. No, it would not be legal to do it as you described. However, there are lots of ways to do it legally: http://en.wikipedia.org/wiki/EME_%28communications%29 http://www.electronics-radio.com/art...r-propagation/ moonbounce-propagation-eme.php etc. Google is your friend. |
#4
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David wrote:
On Sat, 05 Jan 2013 04:02:59 -0800, JIMMIE wrote: The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal. No, it would not be legal to do it as you described. However, there are lots of ways to do it legally: And why not in the USA? Microwave oven mangetrons operate at 2.45 GHz, which is the top of the 2.39 to 2.45 GHz band and should be trivial to pull down a little bit. All modes are allowed in the band. All licencess other than Novice can use the band. |
#5
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![]() "JIMMIE" wrote in message ... The beer got flowing the other day and some of my friends and I got to BSing about the possibility of transmitting a microwave pulse and reciving it reflected off the moon. Plans are to use a microwave oven magnetron for the transmitter. We were wondering if this would be legal. As long as you can keep the microwave in the ham band it would be legal. A number of years ago in the 73 Magazine there was an artical on converting a microwave to a ham transmitter. Some microwaves, if not all operate somewhere aroung 2 to 3 Ghz. You just need to make sure it is tuned to the ham band that is somewhere in that range and you have a license above the novice level. There might be a number of technical resons it may or may not work. |
#6
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Instead of telling you how stupid your question is - I will refer you to the FCC web site - Part 97.....
Part 97 says - no unauthroized transmissions - hence if you cannot ID your signal, you cannot transmit anywhere except 11 meters. 11 meters you are limited to no more then 3 watts AM or 12 watts PEP SSB.. No digital modes and no repeaters on 11 meters. Second off - if licensed as an amateur - you have to follow the band plan. You can't just pick a frequency that sounds quiet and start operating. One amateur recently was fined for operating on 350 Mhz band, I think his fine was around $12,000.00 Third - you would need to limit your transmit power to no more then 1500 watts PEP, and you would have to have the equipment no only to measure the transmit power, but also to do a field survey - since if you had neighbors, you would have to test the exposure limits in the neighborhood. Your records would have to be kept of when you operated and available for review by the FCC - should they come knocking on your door. Most of the band specturm is being used for one thing or another and just because you think that it is high enough that no one would hear you, doesn't mean that someone isn't using it for something legally / commercially.. http://www.arrl.org/part-97-amateur-radio http://www.ntia.doc.gov/files/ntia/p...3-allochrt.pdf
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No Kings, no queens, no jacks, no long talking washer women... |
#7
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![]() "Ralph Mowery" wrote in message m... There might be a number of technical resons it may or may not work. +1 For your information with an ordinary S Band radar: 1000KW peak power into a 35 db antenna and about 1Mhz bandwith You DONT receive echoes from the moon. Very small bandwith is the key of success and magnetron is definitely not a good choice. --- news://freenews.netfront.net/ - complaints: --- |
#8
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Channel Jumper wrote:
Instead of telling you how stupid your question is - I will refer you to the FCC web site - Part 97..... Part 97 says - no unauthroized transmissions - hence if you cannot ID your signal, you cannot transmit anywhere except 11 meters. 11 meters you are limited to no more then 3 watts AM or 12 watts PEP SSB.. No digital modes and no repeaters on 11 meters. 11 meters has nothing what so ever to do with the question. There are many ways to ID a signal, and "unauthorized transmissions" has little to noting to do with IDing. Second off - if licensed as an amateur - you have to follow the band plan. No, you don't; band plans are voluntary. You have to follow the FCC frequency allocations. You can't just pick a frequency that sounds quiet and start operating. One amateur recently was fined for operating on 350 Mhz band, I think his fine was around $12,000.00 Irrelevant. Microwave ovens operate at 2.45 GHz. There is an amateur band at 2.39 to 2.45 GHz. One should probably force the frequency down a little to be safe. Third - you would need to limit your transmit power to no more then 1500 watts PEP, and you would have to have the equipment no only to measure the transmit power, but also to do a field survey - since if you had neighbors, you would have to test the exposure limits in the neighborhood. Not quite. First, there are few, if any, microwave magnetrons capable of 1.5 KW so the requirement to measure output is moot; just pick one that puts out less than 1.5 Kw. Second, a field survey is not appropriate nor needed for a directional antenna pointing into the sky. Your records would have to be kept of when you operated and available for review by the FCC - should they come knocking on your door. Nonsense; the US requirement for ham logging went away a long time ago. Most of the band specturm is being used for one thing or another and just because you think that it is high enough that no one would hear you, doesn't mean that someone isn't using it for something legally / commercially.. Again, nonsense as there is a ham band where microwave oven magnetrons operate. http://www.arrl.org/part-97-amateur-radio http://www.ntia.doc.gov/files/ntia/p...3-allochrt.pdf Read your own links and note the 2.39 to 2.45 GHz ham band. |
#10
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If a person cannot read the answer, then when they become combative, they tend to drift off the subject with their own axe to grind.
If you can get someone to read this to him, the only place other then 11 meters where a person can operate without a license is FRS - which allows one half of one watt of transmit power.... A Band Plan - be it FCC - which I posted or ARRL is one in the same. ARRL band plan tends to just show Amateur Frequencies - since that is all that amateurs are concerned with.... Maybe you never heard of a pink slip - operate sometime on the CW portion in SSB Phone or AM and see how long you can operate before someone gives you heck... Do it on a continous basis - and see how long you can operate before you get a pink slip...
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