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#1
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#2
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Kim wrote:
Test will be in CW no modulation. http://www.arrl.org/?artid=7958 Kim Hasn't this already been done? With a lot less power? |
#3
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On Jan 18, 8:45 am, David wrote:
Kim wrote: Test will be in CW no modulation. http://www.arrl.org/?artid=7958 Kim Hasn't this already been done? With a lot less power? Not at these low frequencies - jw |
#4
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On Jan 18, 6:17*am, Rfburns wrote:
On Jan 18, 8:45 am, David wrote: Kim wrote: Test will be in CW no modulation. http://www.arrl.org/?artid=7958 Kim Hasn't this already been done? *With a lot less power? Not at these low frequencies - jw HAARP Test - Lunar Echo Experiment Broadcast Dates and CW Frequencies 19 JAN 2008 - Maybe 18 JAN in your 'Local' Time Zone. 6,792.5 kHz @ 05:00 ~ 06:00 UTC 7,407.5 kHz @ 06:00 ~ 07:00 UTC 20 JAN 2008 - Maybe 19 JAN in your 'Local' Time Zone. 6,792.5 kHz @ 06:30 ~ 07:30 UTC 7,407.5 kHz @ 07:30 ~ 08:30 UTC |
#5
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It has commonly been done at vhf frequencies, and by some hams on the two
meter band at 146 mhz. James |
#6
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G'day all,
I can hear the tone, very very faintly. Heres a Recording: http://ustream.tv/recorded/elmfbx6yhZSWJryVMS.h2g Its starts ~2min in. I'm still broading live if you want to have a listen live ![]() http://www.ustream.tv/channel/aussie...wave-listening Regards Mark ------------------------------------------------------------------ Location: Canberra Australia Radio: Icom R75 with DSP options Antenna: Cliff Dweller 2 Website: http://aussiedrifter.blogspot.com/ Listen Live via USTREAM.TV: http://www.ustream.tv/channel/aussie...wave-listening James wrote: It has commonly been done at vhf frequencies, and by some hams on the two meter band at 146 mhz. James -- |
#7
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David ) writes:
Kim wrote: Test will be in CW no modulation. http://www.arrl.org/?artid=7958 Kim Hasn't this already been done? With a lot less power? An article should be self-contained, a link should merely be to reference it. We shouldn't have to go digging because someone is too lazy to paraphrase what they want to talk about. (That refers to the original poster.) And if "RHF" and his buddies weren't so intent on jabbering on, it would be far easier to find messages such as these. That said, the issue is about the needed power. Whatever power is at the transmitter, it will be terribly attenuated by the time it hits the moon, and then has to come back the full distance to earth, which means the same amount of attenuation on the return path. We're talking massive distances compared to terrestrial communication. In order to get a reasonable signal when it gets back to earth, one needs to start with a nice strong signal. While there are issues with the higher frequencies, a key advantage is that you can actually get high gain antennas in reasonable size the higher you go in frequency. So the effective radiated power can be far greater than the actual transmitter output power. One way of looking at is that the transmitter signal is aimed where you want it, rather than dissipated in all directions. The lower you go in frequency, the harder it is to get much gain in antenna, for the simple reason that few have the space to make an antenna big enough to get any sort of gain down there. If you can't get the gain with the antenna, then you have to boost power quite a bit, because a lot of it will be wasted. The moon is a pretty small object in the sky, yet the less directional antenna will spray the transmitting signal all over the sky, with very little of it in the direction of the actual moon. A lot of moonbounce expects a reasonable gain antenna at the receiving end. If they really expect average people to be able to receive the signal, then that accounts for an even higger boost of power, since they have to compensate for far lower gain at the receivers. On the other hand, it's far easier to generate power at 6MHz than at 2GHz. And receivers are simpler too. The US Signal Corp were the first to do moonbounce just after WWII, if I remember properly it was about 110MHz, and I don't remember the power level. A couple of hams did it in January of 1953 on 144MHz, though it was only one way. Two way amateur moonbounce happened in 1960 at 1296MHz. For the handful working on it in the early days, it was easy for them to get surplus parabolic dishes, which gave lots of gain, but then getting enough power at that frequency was an issue. On the other hand, unlike the Signal Corp, the transmitter input power was limited to a kilowatt. Receivers were a problem too, since you needed good noise figure, and circa 1953 that meant tubes, and only a handful of relatively obscure tubes were suitable. Transistors helped a lot later. When Sam Harris moved down to work at Arecibo about 1963, he got permission a couple of times to use the actual Arecibo antenna for moonbounce. THat had so much gain that they apparently could hear lots of signals from stations with no more than single yagi. The lowest frequency that hams have done moonbounce was 50MHz, and that didn't happen until the seventies. I don't know if non-hams have done any previous work at lower frequencies. With transistors supplying good gain at VHF and above, and more important good noise figure without all the fussing of earlier days, amateur moonbounce has become relatively common. It's helped because some stations have more than enough gain on their antennas, so simpler stations can be at the other end. Michael |
#8
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On Jan 18, 9:14 pm, AussieDrifter
wrote: G'day all, I can hear the tone, very very faintly. Heres a Recording:http://ustream.tv/recorded/elmfbx6yhZSWJryVMS.h2g Its starts ~2min in. I'm still broading live if you want to have a listen live ![]() Regards Mark ------------------------------------------------------------------ Location: Canberra Australia Radio: Icom R75 with DSP options Antenna: Cliff Dweller 2 Website:http://aussiedrifter.blogspot.com/ Listen Live via USTREAM.TV: http://www.ustream.tv/channel/aussie...wave-listening James wrote: It has commonly been done at vhf frequencies, and by some hams on the two meter band at 146 mhz. James -- The transmitter is loud here in Oregon at about 5db over S9, but I have not been able to hear the bounce yet. Using the Kenwood Ts-950sdx and a 40 meter dipole at 35' 3D |
#9
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![]() An article should be self-contained, a link should merely be to reference it. We shouldn't have to go digging because someone is too lazy to paraphrase what they want to talk about. (That refers to the original poster.) Somebody needs a nap. And if "RHF" and his buddies weren't so intent on jabbering on, it would be far easier to find messages such as these. RHF is a huge help to people on this newsgroup, he finds answers and provides links regularly. That said, the issue is about the needed power. Whatever power is at the transmitter, it will be terribly attenuated............. Chest pounding at its finest. Nice job. 3D |
#10
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On Jan 18, 9:16*pm, (Michael Black) wrote:
David ) writes: Kim wrote: Test will be in CW no modulation. http://www.arrl.org/?artid=7958 Kim Hasn't this already been done? *With a lot less power? An article should be self-contained, a link should merely be to reference it. *We shouldn't have to go digging because someone is too lazy to paraphrase what they want to talk about. (That refers to the original poster.) And if "RHF" and his buddies weren't so intent on jabbering on, it would be far easier to find messages such as these. That said, the issue is about the needed power. *Whatever power is at the transmitter, it will be terribly attenuated by the time it hits the moon, and then has to come back the full distance to earth, which means the same amount of attenuation on the return path. *We're talking massive distances compared to terrestrial communication. In order to get a reasonable signal when it gets back to earth, one needs to start with a nice strong signal. *While there are issues with the higher frequencies, a key advantage is that you can actually get high gain antennas in reasonable size the higher you go in frequency. So the effective radiated power can be far greater than the actual transmitter output power. *One way of looking at is that the transmitter signal is aimed where you want it, rather than dissipated in all directions. The lower you go in frequency, the harder it is to get much gain in antenna, for the simple reason that few have the space to make an antenna big enough to get any sort of gain down there. If you can't get the gain with the antenna, then you have to boost power quite a bit, because a lot of it will be wasted. *The moon is a pretty small object in the sky, yet the less directional antenna will spray the transmitting signal all over the sky, with very little of it in the direction of the actual moon. A lot of moonbounce expects a reasonable gain antenna at the receiving end.. If they really expect average people to be able to receive the signal, then that accounts for an even higger boost of power, since they have to compensate for far lower gain at the receivers. On *the other hand, it's far easier to generate power at 6MHz than at 2GHz. *And receivers are simpler too. The US Signal Corp were the first to do moonbounce just after WWII, if I remember properly it was about 110MHz, and I don't remember the power level. A couple of hams did it in January of 1953 on 144MHz, though it was only one way. Two way amateur moonbounce happened in 1960 at 1296MHz. For the handful working on it in the early days, it was easy for them to get surplus parabolic dishes, which gave lots of gain, but then getting enough power at that frequency was an issue. *On the other hand, unlike the Signal Corp, the transmitter input power was limited to a kilowatt. Receivers were a problem too, since you needed good noise figure, and circa 1953 that meant tubes, and only a handful of relatively obscure tubes were suitable. *Transistors helped a lot later. When Sam Harris moved down to work at Arecibo about 1963, he got permission a couple of times to use the actual Arecibo antenna for moonbounce. *THat had so much gain that they apparently could hear lots of signals from stations with no more than single yagi. The lowest frequency that hams have done moonbounce was 50MHz, and that didn't happen until the seventies. *I don't know if non-hams have done any previous work at lower frequencies. With transistors supplying good gain at VHF and above, and more important good noise figure without all the fussing of earlier days, amateur moonbounce has become relatively common. *It's helped because some stations have more than enough gain on their antennas, so simpler stations can be at the other end. * *Michael MB, Thank you for your 'brief' Synopsis of the History of Moon-Bounce Signals in your very own words. For the Newbies out there who have never heard of Moon-Bounce Signals and HAARP : Here are three links to learn more about Earth-Moon-Earth (EME) Communications -aka- Moon-Bounce 7 MHz Moonbounce - Scientists Detect http://www.southgatearc.org/news/january2008/haarp.htm The HAARP Lunar Echo Experiment Lowest Frequency Radar Echo From The Moon Earth-Moon-Earth (EME) Communications http://en.wikipedia.org/wiki/EME_(communications) SETI League Moonbounce Signal Detections http://www.setileague.org/eme/emepix.htm Plus WHAT IS "HAARP" - http://www.haarp.alaska.edu/ The "High Frequency Active Auroral Research Program http://en.wikipedia.org/wiki/High_Fr...search_Program link-it-up {look-it-up} and learn for yourself ~ RHF |
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