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#1
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In article , Robert Casey
writes: Contests working Earth-Mars contacts should be interesting, when you remember that speed'o light means that radio signals take about 5 to 15 minutes one way to make the trip... If my math is right, the one-way transmission time works out to between 188 seconds at closest approach to 688 seconds maximum. But you can count on contest ops to figure a way to make that work. Use the transmission time as a 'buffer' of sorts. Not a problem. SO2R is just the beginning. 73 de Jim, N2EY |
#2
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#3
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#5
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In article , Leo
writes: On 09 Aug 2004 23:45:24 GMT, (Len Over 21) wrote: In article , (N2EY) writes: (N2EY) wrote in message ... In article , Robert Casey writes: Contests working Earth-Mars contacts should be interesting, when you remember that speed'o light means that radio signals take about 5 to 15 minutes one way to make the trip... If my math is right, the one-way transmission time works out to between 188 seconds at closest approach to 688 seconds maximum. Well, it's not correct. The 188 seconds is pretty close but the 688 is way off because I added the Earth orbit radius rather than diameter. Or perhaps grabbed the distance data off the wrong website? ![]() Nah...just Internet QRM...he was reading video instead of morse. :-) Oh, my! Had anyone else come up with those numbers you would have sent many a multi-screen message accosting them of error-prone perfidy! :-) I can see the reply now: "Wrong again, ..xxx.......", followed by the usual Jim-style rub-the-nose-in-it verbiage. Plus a nice little macro to insert in other, later messages, claiming that the error-maker "always made errors" and isn't trustworthy and may not use deoderant... Here's a more exact calculation: Per NASA website, the Earth's orbit varies from 149.5 to 149.7 million kilometres and Mars' orbit varies from 204.52 to 246.28 million kilometres. The closest the two planets approach is 204.52 - 149.7 = 54.82 million kilometres The farthest apart they get is 246.28 + 149.7 = 395.98 million kilometres Using 0.3 million km/sec (that's 300,000,000 metres/sec) as the speed of light, we get: 54.82 / 0.3 = 183 sec (3 minutes 3 seconds) 395.98 / 0.3 = 1320 sec (22 minutes 0 seconds) give or take...... What, no EXACTNESS? Speed of light isn't EXACTLY that nice round figure. Tsk, tsk. Precision is for others. True, but the unique criticsm is HIS... :-) But you can count on contest ops to figure a way to make that work. Use the transmission time as a 'buffer' of sorts. Not a problem. Ingenious use of the delay interval would permit pretty good contest rates. Of course the ability to work duplex would be a plus. I am non-plussed. With a 44 minute round-trip time you wouldn't need any sort of T/R switch, just solder some lands on a PCB to do the same job to go from Rx to Tx and back again. :-) For rag chewing, contacts between fixed nonpolar stations on each planet up to about 12 hours long are possible if the locations are just right at both ends. You could WEAVE the rag material, cut it to shape, sew it up in the time of those contacts... :- No problem, though, for someone who takes 48 hours to reply to this little Usenet-based QSO - and fails to reply in context of the thread at that. Think of it as "a buffer." :-) "I just noticed that I was incorrect - all by myself!" Duh. Well, at least he NOTICED... He took the time out to look...away from Worked All Usenet logging... SO2R is just the beginning. Of course the reason no one - professional or amateur - has been awarded the Elser-Mathes Cup is because it requires operators at both ends of the QSO. Human space programs won't be in a position to do that for decades yet. Ah! One of the remarkable OBVIOUS statements! :-) And a brilliant one at that.....you need someone on the other end of a QSO? Sunnavagun! He could have called for the comic strip character "Obviousman!" I hearby nominate you for three or four votes in the Department of Redundancy Department. But not the Department of Mathematics. I keep having the crazy idea that a relative was working at JPL when they had that conversion error on a probe a while back. The one that failed due to the wrong constant or something, metric instead of english... Nah. Okay, now what is the PATH LOSS and what kind of Tx power is needed at each end for a given S:N ratio? Can you get by on amateur radio power levels? Without violating any of the regulations? How about Doppler Shift? How much? LHA / WMD |
#6
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Leo wrote in message . ..
On 8 Aug 2004 11:14:28 -0700, (William) wrote: Leo wrote in message . .. On 07 Aug 2004 19:53:20 GMT, (Len Over 21) wrote: In article , PAMNO (N2EY) writes: In article , Robert Casey writes: Contests working Earth-Mars contacts should be interesting, when you remember that speed'o light means that radio signals take about 5 to 15 minutes one way to make the trip... If my math is right, the one-way transmission time works out to between 188 seconds at closest approach to 688 seconds maximum. Hmmmm - interesting math for an MSEE..... and quite incorrect indeed. Good amateur-level research skills, though. ![]() His skills rusty. Works for EPA. Solve global warming. Nah - I'm pretty sure he claims to have had a successful career in electrical engineering - a field where, I suppose, being off by over 100% in a calculation would be completely acceptable (so THAT'S what fuses are for!). 8*p That can all be blamed on the pentium floating point zero. That, and being employed full time in amateur radio, and currrently working on his WAU (Worked All Usenet). One day he woke up and found out he had a career in amateur radio. A bit short that. According to my Almanac ("World Almanac and Book of Facts 2001" published by World Almanac Books, p. 587), the minimum to maximum distances of Earth to Mars are 34 to 249 Million miles. At 186,000 Miles per second, the ONE-WAY time works out to be 183 to 1339 seconds (3.05 to 22.3 minutes). Now them's the right numbers! The following website confirms these distances, after conversion from km to miles: http://www.absoluteastronomy.com/planets/mars.htm Ooops. Now you've done it. Never, Ever back-up anything Len has posted. Here comes Hiram's Hammer! Duck! A single two-way contact, one transmission at each end, would take 6 to 44 minutes to complete, depending on the planetary positions. The limiting factor on "rag chews" would be limited by rotation of both planets. :-) ...and those periods when that pesky moon of ours is in the path ![]() But it's made of cheese. Only very slight attenuation at HF. Of course, Rev. Jim, you WILL call MY calculations "incorrect" or "wrong" or something like that, won't you? :-) Careful - you're contradicting an expert here - ain't never been wrong yet! 8*p Hi, hi! It's true! Just ask him! 73, Leo Jim won't say. Just ask him! Hi, hi. |
#7
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On 11 Aug 2004 03:25:21 GMT, (Len Over 21) wrote:
snip BTW, you mentioned in an earlier post that you have a Patent registered to you, in the area od radio. Interesting - mind if I ask what it was? U.S. # 3,848,191 - Pulse Compression Receiver with AGC, granted in 1974, assigned to RCA Corporation. Sole inventor on patent. Missed two other applications due to being too close to prior art. Basically it is a pulse processor and operating in an environment of many different pulses, only a few of which come close to being in synchronism with the system. The application was for SECANT, an R&D project for 4 years at RCA, the acronym standing for SEparation and Control of Aircraft by Non-synchronous Techniques. SECANT was an aircraft collision avoidance system and in direct R&D competition with a modified helicopter station-keeping system done by Minneapolis-Honeywell. Both the RCA and Minnie-Honey systems were flight-tested successfully in PA at the (former) Naval Air Development Center (NADC). Flight testing local in PA, at the Patuxent River range, and at Key West, Florida, observed by FAA troops locally as well as USN and USA people. First air tested at Kern County Airport #7, Mojave, CA...("Mojave International" in fun) now the site for Scaled Composites, the first company to make it into space privately. SECANT worked at 1.6 GHz nominal bandcenter. The final version (of three) in 1974 used 8 SAW (Surface Acoustic Wave) matched bandpass filters done on quartz substrates (done at Sommerville, NJ) at 1 MHz bandwidths centered between 55 and 64 MHz. I got to play with the SAW filters and the final version IF-detectors plus the pulse pre-processor. Al Walston, W6MJN, and I shared responsibility for the Tx and Rx parts. Jim Hall, KD6JG, was the engineering technical manager over the last two versions of SECANT and all of RIHANS, another R&D program, again working in L-band at the RF level. The U.S. government scuttled any more testing funding in 1974 for both the RCA and Minnie-Honey systems, opting for a less-tested ATC transponder modification which is now in use, but only by the air carriers and large executive aircraft. TCAS? (now TCAS II) Military doesn't use that system. MIT had friends in higher places to sway gubmint opinion. RCA Corporation began (well before WW2) as a place to hold U.S. patents and try to keep control on the then-new technology of radio. As a result, RCA built up a fantastic legal staff and pursued patent filings aggressively. Back in '74 the average cost of any electronic patent application cost about $6000, nearly all of it being taken up by the non-patent-office Search costs. Corporate employees of the lower levels would not get much chance to patent anything unless a corporation had a large legal staff. I was lucky in getting a sole patent award and don't sweat the other two at RCA nor the one multiple-inventor patent turn-down at Electro-Optical Systems (Xerox division). [sometimes good minds think alike! :-)] Very impressive - thanks for the summary. I'd never heard of the SECANT system before. That would have been quite a challenge back in '74 - all discrete components, no microprocessors, no CAD tools or circuit emulators....real hands-on design work. No wonder you're getting so much heat here, Len - clearly, you are out of your league. Are you aware that there are folks here who have successfully assembled their own Elecraft kits, and built working CW transmitters from plans? :-) :-) :-) |
#8
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Subject: European Mars probe to use 80meters to look for Martian water?
From: Leo Date: 8/11/2004 6:31 AM Central Standard Time Message-id: On 11 Aug 2004 03:25:21 GMT, (Len Over 21) wrote: snip BTW, you mentioned in an earlier post that you have a Patent registered to you, in the area od radio. Interesting - mind if I ask what it was? U.S. # 3,848,191 - Pulse Compression Receiver with AGC, granted in 1974, assigned to RCA Corporation. Sole inventor on patent. Missed two other applications due to being too close to prior art. Lennie-to-English translation: "I was a bit too slow copying the files so I could make it look like it was my idea first." No wonder you're getting so much heat here, Len - clearly, you are out of your league. Are you aware that there are folks here who have successfully assembled their own Elecraft kits, and built working CW transmitters from plans? None of the "heat" Lennie is taking is due to his alleged professional career or what he thinks he knows...it's about lying, antagonism, profanity and not doing what he says he's going to do. In short...he's a creep. Steve, K4YZ |
#9
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Leo wrote:
On 10 Aug 2004 03:16:20 GMT, (Len Over 21) wrote: In article , Leo writes: On 09 Aug 2004 23:45:24 GMT, (Len Over 21) wrote: In article , (N2EY) writes: (N2EY) wrote in message ... In article , Robert Casey writes: Contests working Earth-Mars contacts should be interesting, when you remember that speed'o light means that radio signals take about 5 to 15 minutes one way to make the trip... If my math is right, the one-way transmission time works out to between 188 seconds at closest approach to 688 seconds maximum. Well, it's not correct. The 188 seconds is pretty close but the 688 is way off because I added the Earth orbit radius rather than diameter. Or perhaps grabbed the distance data off the wrong website? ![]() Nah...just Internet QRM...he was reading video instead of morse. :-) Oh, my! Had anyone else come up with those numbers you would have sent many a multi-screen message accosting them of error-prone perfidy! :-) I can see the reply now: "Wrong again, ..xxx.......", followed by the usual Jim-style rub-the-nose-in-it verbiage. Plus a nice little macro to insert in other, later messages, claiming that the error-maker "always made errors" and isn't trustworthy and may not use deoderant... We've read enough of those, alright! Here's a more exact calculation: Per NASA website, the Earth's orbit varies from 149.5 to 149.7 million kilometres and Mars' orbit varies from 204.52 to 246.28 million kilometres. The closest the two planets approach is 204.52 - 149.7 = 54.82 million kilometres The farthest apart they get is 246.28 + 149.7 = 395.98 million kilometres Using 0.3 million km/sec (that's 300,000,000 metres/sec) as the speed of light, we get: 54.82 / 0.3 = 183 sec (3 minutes 3 seconds) 395.98 / 0.3 = 1320 sec (22 minutes 0 seconds) give or take...... What, no EXACTNESS? Speed of light isn't EXACTLY that nice round figure. Tsk, tsk. Precision is for others. True, but the unique criticsm is HIS... :-) True enough! But you can count on contest ops to figure a way to make that work. Use the transmission time as a 'buffer' of sorts. Not a problem. Ingenious use of the delay interval would permit pretty good contest rates. Of course the ability to work duplex would be a plus. I am non-plussed. With a 44 minute round-trip time you wouldn't need any sort of T/R switch, just solder some lands on a PCB to do the same job to go from Rx to Tx and back again. :-) For rag chewing, contacts between fixed nonpolar stations on each planet up to about 12 hours long are possible if the locations are just right at both ends. You could WEAVE the rag material, cut it to shape, sew it up in the time of those contacts... :- No problem, though, for someone who takes 48 hours to reply to this little Usenet-based QSO - and fails to reply in context of the thread at that. Think of it as "a buffer." :-) Or an intellect amplifier.... :-) "I just noticed that I was incorrect - all by myself!" Duh. Well, at least he NOTICED... He took the time out to look...away from Worked All Usenet logging... Heh. SO2R is just the beginning. Of course the reason no one - professional or amateur - has been awarded the Elser-Mathes Cup is because it requires operators at both ends of the QSO. Human space programs won't be in a position to do that for decades yet. Ah! One of the remarkable OBVIOUS statements! :-) And a brilliant one at that.....you need someone on the other end of a QSO? Sunnavagun! He could have called for the comic strip character "Obviousman!" Reminds me more of "Politenessman", from the old National Lampoon magazine.....with his steel hankie......remember him? I hearby nominate you for three or four votes in the Department of Redundancy Department. But not the Department of Mathematics. I keep having the crazy idea that a relative was working at JPL when they had that conversion error on a probe a while back. The one that failed due to the wrong constant or something, metric instead of english... Nah. Nah! Okay, now what is the PATH LOSS and what kind of Tx power is needed at each end for a given S:N ratio? Can you get by on amateur radio power levels? Without violating any of the regulations? How about Doppler Shift? How much? Betcha there gonna be chicken sounds on that...no answer. :-) So far, you could hear a pin drop....... Tell us what the path loss and and Power for a given S/N ratio is. Pick a position and date for that position and tell us. Tell us what the Doppler shift is over the length of a short QSO, starting at the time of of start Assume a DX style QSO with a short feedback message to insure actual reception on both ends, say a 35 second transmission. Then the same for the return message. At this time I don't know those details, but I'll be happy to check them out once you've posted them. Add anything I have forgotten but may need to know. - Mike KB3EIA - |
#10
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Subject: European Mars probe to use 80meters to look for Martian water?
From: Mike Coslo Date: 8/11/2004 9:47 AM Central Standard Time Message-id: Tell us what the path loss and and Power for a given S/N ratio is. Pick a position and date for that position and tell us. But...but...but...MIKE! Lennie's STATED position is that he's "...only here to civilly debate the Morse Code test issue" You wouldn't expect him to VIOLATE his own WORD, would you...?!?!...He's a PROFESSIONAL! 73 Steve, K4YZ |
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