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Thursday, January 14, 2016
Alan Wolke W2AEW Moonbounce with Project Diana
Alan mentioned this in his interview with Eric on the QSO Today podcast. I really liked Alan's video of the Project Diana moonbounce commemoration. That HUGE display showing outgoing signals and then the echoes off the moon was really cool. EME is on my to-do (someday) list.
It was my first exposure to EME. Actually my second, if you count the trial runs from the previous weekend. I didn't make any contact myself, but it was great to witness it. The coolest part was at the end where we had a few kids come up and speak "november 2 mike oscar" into the mic, and then watch their expression when they heard their voice come back from the moon!
About 1965, Sam Harris got permission to use Arecibo for amateur moonbounce, fairly early in the life of that radio telescope. The report was that it sounded like 20 metres at their end. The difference being that Arecibo got so much gain that not much in the way of an antenna was needed at the other end.
The rest of the time, you needed a big antenna, at and a good converter at a time when those didn't have such great noise figure, or required a lot of fussing (ie parametric amplifiers). I remember one review of a Nuvistor converter, someone comparing it to a 416 converter (the 416 being about as good as it got for tube reception) and saying "it's at least as good as my 416 converter ("or, I need to tune up my old converter").
But Gasfets have helped a lot, even better noise figure than the best of the old days. Receivers are generally better, and all that "under the noise" stuff that was talked about fifty years ago can now be done in digital. Getting up to 144 or 432 is easier, and I suspect power at those frequencies is easier too.
ANd then enough people have moonbounce stations, especially with good antennas, that the entry requirements are lesser. The base level isn't way up there, some of it can be balanced out because there are some good stations out there. So it lessens the requirements of all stations, though it may mean one can only contact a subset of moonbounce stations.
It was my first exposure to EME. Actually my second, if you count the trial runs from the previous weekend. I didn't make any contact myself, but it was great to witness it. The coolest part was at the end where we had a few kids come up and speak "november 2 mike oscar" into the mic, and then watch their expression when they heard their voice come back from the moon!
ReplyDeleteIt has become much easier to do moonbounce.
ReplyDeleteAbout 1965, Sam Harris got permission to use Arecibo for amateur moonbounce, fairly early in the life of that radio telescope. The report was that it sounded like 20 metres at their end. The difference being that Arecibo got so much gain that not much in the way of an antenna was needed at the other end.
The rest of the time, you needed a big antenna, at and a good converter at a time when those didn't have such great noise figure, or required a lot of fussing (ie parametric amplifiers). I remember one review of a Nuvistor converter, someone comparing it to a 416 converter (the 416 being about as good as it got for tube reception) and saying "it's at least as good as my 416 converter ("or, I need to tune up my old converter").
But Gasfets have helped a lot, even better noise figure than the best of the old days. Receivers are generally better, and all that "under the noise" stuff that was talked about fifty years ago can now be done in digital. Getting up to 144 or 432 is easier, and I suspect power at those frequencies is easier too.
ANd then enough people have moonbounce stations, especially with good antennas, that the entry requirements are lesser. The base level isn't way up there, some of it can be balanced out because there are some good stations out there. So it lessens the requirements of all stations, though it may mean one can only contact a subset of moonbounce stations.
Michael