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Ham Operator Sets New Miles-Per-Watt World Record
DoctorPepper writes "A ham radio operator in New London, North Carolina correctly copied an 80 meter CW beacon in Wappingers Falls, New York, a distance of 546.8 miles. The kicker is, the beacon station, an Elecraft K1, was putting out 40.6 uW (40.6 millionths of a Watt) -- which works out to 13,467,980 miles per watt!"
and the old record is...?
Ham Radio continues to excite. I think there's something romantic about it that draws geeks towards its coils - how else do you explain the way it has enthralled so many in its history? The venerable Woz is one. Can anyone else recall any Ham Radio enthusiasts who went onto bigger things in Tech?
Mu is a perfectly acceptabe ASCII character that most command line interfaces can easily display, guys. Fix it. Sorry, Timothy.
Can you hear me now?
In english, please?
Quid festinatio swallonis est aetherfuga inonusti?
Africus aut Europaeus?
Ham radio people are are truly the geeks' geeks. The mad-science of it all truly inspires.
So will this make it easier to bring Dennis Quaid back from the dead?
Cheers,
IT
Power corrupts. PowerPoint corrupts absolutely.
Could someone please explain the significance of this to a lay geek?
they're always screwing my wifi over, ugh!
to think, you wish they'd just all grow old and die!
but noooooo, they grow old, and set hamd world reccords..
it just isn't fair!
Does anyone know what the previous record was? I'm not at all familiar with hamming, though it strikes me as quite interesting based on this and the recent tsunami-related story (primarily the ensuing comments).
Honor Among Slackers. A veri
Man B: what?
Man A: 13,467,980 miles per watt
Man B: What?
Man A: Watt?
Man B: What!?!?!?
Man A: Watt!!!!
Man B: Forget it, I'm not playing this stupid thing, go be an A$$.
omg.. after reading that article I got the feeling that there are people even more geeky than computer geeks.
"I'm thrilled the record was set by an all-American team using all-American equipment." The Ten Tec receiver is manufactured in Severville, TN and the Elecraft transmitter is produced in California and offered as a kit.
yes, so relevant...
I don't think the math is right there. If it's a straight mast then the wave front will spread out radially.
So increasing the power wouldn't give you a linear increase in distance like the OP seems to believe it would.
Simon.
Ohm my! That Hertz!
This may be what the professor was talking about in Back To The Future.
I might finally know what a jiggawatt is!
Even most directional antennas will not give you linear 'watt to distance' amplification.
In worst case it is a power^1/3. So for 40 milliwatts to 1 watt amplification you'll get some 30x distance (at worst), but never 2500x, unless some wicked atmospheric conditions happen.
yeah? so watt?
...it's the efficiency of your output.
From the comments at the article site:
While the ability to receive a very weak signal is always interesting (and exciting for QRPP operators), converting results into "miles per watt" is an absolutely useless way to express results!!
The whiner goes on to say:
At 1.5 MHz data in CCIR Thirteenth Plenary Assembly (vol VI report 264-3 p 108) shows attenuation increases ~10 dB when path length goes from 500 km to 1000 km. Doubling skywave path length at 500 km when at 1.5 MHz increases loss 10dB, NOT 3 dB. Doubling distance again (same frequency) from 1000 km to 2000 km results in an additional ~15 db loss! 2000 km to 4000 km is about 22 dB more loss. This is based on measured data.
While most of the numbers leave me with a blank look, one thing is clear: the poster missed the point. The accomplishment is cool because of the geek factor, not because it's going to lead to a new radio in your car. Therefore, the measurement of the achievement doesn't *have* to be "useful".
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
Sign me up for the first Wireless Communications via Ham radio Ipaq.
The Property of One's : "The Oneitude is directly proportional to the Colditude of the one." - S.B.
I hope he doesn't pick up ham radio messages from the past and communicate with someone.
That'd be horrible. Who knows what he's been altering in our timeline.
------
insert sig here,here, and here
More like, WHAM radio!
According to the article, the receiving operator was using a 1,000 foot antenna. I'd be more impressed if the antenna were smaller.
"Lack of technical competence coupled with the arrogance of power, as usual, leads to no good end."
This seems an odd way to compare accomplishments. If you use this metric, then you reach the false conclusion that doubling wattage doubles distance. Since signal strength deteriorates with distance squared, a better metric might be miles^2 per Watt.
Example using round numbers. Philip transmits 10 miles using a 10W transmitter. Sally transmits 19 miles using a 20W transmitter. If you use miles per Watt to compare, it looks like Philip achieved better results, when in fact Sally did.
now we should realy start wearing the tinfoil hats
I doubt that we will ever figure out - and I suspect that even if we did figure out we couldn't do much about it
My cell phone can talk around the world on it's itty
bitty power output.
Got Code?
Today is a turning point in history, in technology and most of all - wireless communications. With the addition of a 8 meter antenna, we'll be free to connect wirelessly to anyone in our neighbourhoods. Gone are the days of dialup, cable internet and snail mail. I'll be able to use a wireless provider, hundreds of kilometres away!
Why is it that anyone who tries to add extra vowels to words is an asshole?
It's as sensible as measuring distance travelled/max acceleration of a car. There simply isn't a linear relationship between these things and so dividing one by the other doesn't give you anything interesting. If we start dividing random variables by each other and reporting the result on /. we'd never get to read any interesting news.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
The units here are watts per square mile. Your typical FM radio station has a range of maybe 50 miles and is running maybe 10 kwatts, so they're doing 4 watts per square mile. This guy is doing much better. My own power/distance record, back when I was active in ham radio, was 7000 miles on about 25 watts, or 5.10204082 × 10**-7 watts per square mile.
You might wonder how it's remotely possible for there to be a gap of seven to ten orders of magnitude. Why aren't we bothered by FM radio stations on the other side of the world? There is a qualitative difference between the behavior of radio waves above and below about 30-50 MHz (the FM band starts at 88 MHz). Conditions permitting, the lower frequencies can refract in the ionosphere and come back down to earth along non-straight-line paths. That's why shortwave radio stations on other continents can be heard.
WWJD for a Klondike Bar?
This is all nice and stuff but let's face it - Ham Radio is dead.
Although Ham was a popular hobby in the 1970s and 80s, it has been basically killed by cell phones and internet. The number of young people wanting to become Hams has drastically decreased and the only people still doing Ham are white-haired foggies from the Apollo moon missions and Cold War era.
Sad but understandable as a consequence of our technological progress.
And.. yes.. I am/used to be a licensed Ham.
From TFA: "I'm thrilled the record was set by an all-American team using all-American equipment."
I've always wondered why you (Americans that is, but the British also do this) are so proud of everything you achieve. Anyone care to explain this? The fact that this was was achieved Americans is of absolutely no value to the story...
On the other hand, maybe the fact that *you* achieved it may make the story newsworthy. ;-)
Phonnneee hoommmeeee... eeeee ttttttt
...wish I could turn my ham into a radio.
Commenting on his remarkable success, Bill said "I've spent 25 years on 80 & 160 listening to below noise level signals ..."
Below noise signals sounds paradoxical, but people do it all the time. If you're in a noisy restaurant, you can pick out individual noises even though they are much quieter than everyone else. The key is that you have an idea of what you expect to hear - you generally know the tone of their voice, know what sounds make words, know what words make understandable sentences.
Imagine if the signal had been spread-spectrum. Spread-spectrum signals are stealthy because, they to, can be recovered from below the noise floor. Basically, with an idea of what to expect, the receiver's processing can effectively raise the signal above the noise floor. Instead of sending short tones for each bit, a series of tones are sent for each bit (a chip) - one chip for zero, and a different chip for one. It's a lot easier process a sound and see which chip it sounds closer to than it is to see if one particular tone is there or not.
So, in summary, this guy's brain played a lot in the reception to pick out a signal from the noise. I wonder if the next record will be set with a spread spectrum transmitted signal and a digital processing receiver.
HIV Crosses Species Barrier... into Muppets
You lost the election. Badly. Stop crying and get over it.
I'm not a ham, but it seems to me that there isn't much basis in fact for an assertion that amateur radio is "horribly outmoded".
My guess is that you think it has been made obsolete by the Internet. That strikes me as being palpably untrue, as well as a bit like saying the fact that so many people eat pizza means good restaurants are outmoded.
Two different technologies, two different sets of purposes and abilities.
-- Slashdot: When Public Access TV Says "No"
I don't think the measurement is provided as a predictor of how many watts you'll need to send a signal a given distance with the equipment; it's just a ratio normalized to one watt for the sake of comprehension.
paintball
So when they communicate with ham radio =) they use morse code.. They don't need to send any voice signals over...
Okay.. Ham Radio is dead, right ?
:5 6&tid=215
And you say this 2 days after the Slashdot article entitled
Ham Radio Served as Main Link to Disaster Area
http://slashdot.org/article.pl?sid=05/01/02/23432
That's a quick death it died after having proved that it's still worth having as an alternative.
I'm thinking that this is a case where less traffic in the Ham world of frequencies has made it easier to get more distance. It's easier to hear someone in a empty room than one full of yapping people.
Anyone got any numbers on how crowded the frequency spectrum involved is, and how much it's changed.
Bacardi + slashdot = negative karma.
Does this mean that NASA can use this to communicate with future rovers?
After a joke like that, I bet I could hear a pin drop.
For maximum pessimism, say that it's currently putting its maximum 315 watts into "phoning home" -- I work this out to 26.1 million miles per watt. (My guess is that realistically it's more like 1e3 times that.)
Sorry HAM-guy, but Voyager still kicks yer butt.
Cheers,
Richard
I think I know what watts are, I know what miles are, and I somewhat understand the concept of ham radios. I still don't understand a relationship between the three (maybe I'm being stupid).
Anyone care to explain to the unwashed masses what this means?
My mind works like lightning. One brilliant flash and it is gone.
Uh...did you see the news lately?? Tsunami? Well...all the cell sites in the affected areas are dead. guess what is the only link in or out? That's right...ham radio. Many of those areas don't have cell period.
l;sjdflkjdslksdjfkjsdflksjdflkjs werwerewrwerewrew
...transmits at 20 watts and is 1.2 billion km from earth. That is ~37.5 million miles per watt, and I am pretty sure that Voyagers transmitter is weaker than that by a good deal.
The 1000 miles per watt award is fairly easy to get. I exceeded it twice recently, when I worked ES5MC in Estonia from California with 4.5 watts with my Elecraft KX1 and a pack of AA batteries and a 28ft wire in a tree in central California, and OH9SCL in Santa Claus Land (Rovaniemi Finland, news, news) with the same radio from a parking lot by the San Francisco Bay.
Uh, ever hear the one about keeping your mouth shut and not prooving something or other??
There are no repeaters on 80m. Repeaters are used on VHF, UHF and higher freqs - those line of sight type freqs (50Mhz and above). 80m (3.5455 MHz) ain't 'LOS' by a long shot.
So there you go. Still champion.
Put a spacecraft in outer space and propel it by some mechanism. Hopefully, it would keep keep the velocity till eternity (unless ofcourse you consider the miniscule probability that it may collide with some planetary mass).
the beacon station was putting out 40.6 uW -- which works out to 13,467,980 miles per watt!"
Circumference of earth: 25,000 miles
Earth-Moon distance: 240,000 miles
Earth-Sun distance: 93,000,000 miles
Thanks for the tip ;)
Is there a theoretical maximum limit to how far a single bit can be propagated in 1.0 watt of laser power at, say, 1m wavelength? Photons don't seem to accelerate from their quantum ground state before emitting from an electron shell, so does their max-velocity travel consume any energy? Aren't the photons traveling in a spiral path around the axis of their direction, which consumes energy to move their tiny mass equivalence off their inertial path?
--
make install -not war
Moderators, this may have been intended as a troll. It certainly isn't entirely true. But it's true enough that we shouldn't moderate it out of sight.
My father was a ham, and I'm not. Even in the '70s and '80s the old fogies were making it unattractive. My father, who was an old fogie himself, lost interest in everything but VHF and repeaters, in part because of the old fogies. I never could get excited enough to learn Morse, so never got a ham license. I did get a BSEE with an emphasis in communications, but never a ham license. There were just too many other fascinating things to do.
It's the code requirement which is keeping the masses out of ham radio, and that's kept in place by the old fogies who want to keep the CB riff-raff out. Unfortunately, if you aren't a fellow old fogie (sometimes even if you are!) they're ruder and nastier than the CB riff-raff.
Today, there are more technically interesting ways to communicate, and there are more practical ways to communicate, than DX over CW. Except for the old fogies, DX over CW is dead. The old fogies who advocate that as the only acceptable way to do ham radio are doing their best to ensure that all the many exciting, practical things that ham radio could be are dead, too.
See what I've been reading.
Is whether HAM geeks are kosher.
When/if BPL is widely deployed, the noise floor will be so jacked that achievements like this will become imposible.
Can't believe non one else has twigged to that one yet.
Yes it is out moded and full of old geezers that sit in their garages and talk to others like them. But I never cease to be amazed that I can sit at my meager station and with 25 watts talk to someone in Nome, AK or in the middle of the Indian Ocean. Nerdy and Geeky for sure but still totally interesting.
Yeah, but did Netcraft confirm it?
That's the important part.
WATTS UP!
Of course you could flip this relationship on its head to make a new record: build a femtoWatt (10^-15) level transmitter and place it, say, 1mm away from the receiver. If that could work, you'd be getting 10^12 metres/Watt compared to this record of approx 2x10^10 metres/Watt.
Engineering is the art of compromise.
You don't need to know Morse code to get a Technician license.
As an amateur radio operator, I hear things like this all the time. Maybe it's true in your neck of the woods, but for the most part I think you're totally off base.
I'm 24 years old. I've had my ticket for over a year now. Of all the local hams I've met, most of them are under 50 years of age. I have contemporaries who are involved in a wide range of different activities on amateur radio. Sure, some of us (myself included) have basic Technician level tickets, and we mostly use amateur radio to comunitcate locally and rag chew about the latest crazy drivers, stuff that we could probably do with Nextel's and their ilk, but there's still stuff that you can't do with more modern tech. Heck, I volunteer for a local RACES group, and we can go places and get voice and packet data working where even the county's super duper trunking radio system won't go. That's where amateur radio comes into its own - time and time again ham's have been able to get comms into and out of a disaster area when all other means of rapid communication have failed. There's no more heartwarming feeling to me than to be able to pass that piece of traffic that lets someone know their loved one is ok.
In short, the beauty of amateur radio is you can do just about anything you put your mind to, like this guy did.
If you've had some bad experiences, or found yourself being poo pooed by the same white haired hippies you refer to, I'm truly sorry. But there are still a plethora of usefull and fun things to do with amateur radio, and as long as there is that one person who picks up the mic and calles CQ, then amateur radio will be alive.
Oh, one other thing... if you're really that bitter about it, do the rest of us a favor... stay off the air.
Tell me the first name of that Arafat fellow. Yasir! ...
Somewhat more recently I did this back when Hu Jintao was only vice president ...
A feeling of having made the same mistake before: Deja Foobar
Not only do we excel at engineering, we also excel at compassion. Below is a tally of the latest contributions to the relief effort in Southern Asia.
1. USA $350 million + several hundred million dollars of indirect aid (e.g. naval armada arriving near Sri Lanka to do search and rescue)
2. Japan $500 million
3. Australia $810 million
4. China (including Taiwan province and Hong Kong) $8 million
The compassion of Westerners can objectively be said to be greater than the compassion of Chinese by, at least, 2 orders of magnitude.
Perhaps, our compassionate and supportive society creates the right environment for people who perform poorly on written tests but who excel at engineering creativity. It makes you wonder, don't it?
Miles per watt indeed! What tosh.
Not only do we excel at engineering, we also excel at compassion. Below is a tally of the latest contributions to the relief effort in Southern Asia.
1. USA $350 million + several hundred million dollars of indirect aid (e.g. naval armada arriving near Sri Lanka to do search and rescue)
2. Japan $500 million
3. Australia $810 million
4. China (including Taiwan province and Hong Kong) $8 million
The compassion of Westerners can objectively be said to be greater than the compassion of Chinese by, at least, 2 orders of magnitude.
Perhaps, our compassionate and supportive society creates the right environment for people who perform poorly on written tests but who excel at engineering creativity. It makes you wonder, don't it?
It's worse than that. Repeaters listen on one frequency, and repeat on another. The transmit frequency must be different enough from the input frequency or it will step on the incoming signal. Remember, the signal received by waves hitting your antenna from the air is many many many times weaker than the signal driven by your power amplifier.
First off, if the grandparent post has really gone beyond simple dissent.
Secondly, as others have mentioned, you can get your Technicians level license without knowing morse code. You still have to take and pass the test, so it's not a free ride like CB, MURS, FRS, GMRS, etc.
So the old fogies bother you? There sure seems to be a lot of spectrum out there for you to communicate on. Use the modern tech to your advantage. Go talk to other people far away using IRLP internet connected repeaters. Go talk to people around the world by working an amateur radio satellite. There's all sorts of possibilities out there. What continues to amaze me is that people don't go looking for them.
If you're using a handheld, it's pushing a watt or two. Five watts, if you still use a "bag" phone.
Transmitters: An Elecraft K1 costs about $300. What did the Huygens probe cost?
Receivers: a Ten Tec Orion costs about $3300. What does a VLBA cost?
"National Security is the chief cause of national insecurity." - Celine's First Law
Sure, I can do that to with a 1:1 match into a 30dB gain antenna... of course at 80m that would be a big sucker... 73 k06eb
Was it a digitally signed transmission?
By my calculation, the true miles-per-Watt would "only" be about 16K miles, if the transmitter is omnidirectional, which would make its signal strenght decrease with distance-to-the-power-of-three: ((1/0.0000406)^(1/3))*546.8 (just over 15909) miles is the distance you could reach with one Watt, if 0.0000406 Watts gets you 546.8 miles.
(of course, if it's a record using the dumb/linear way of calculating it, it's still a record when calculated the other way)
'Miles per watt' is a stupid, meaningless metric. Since watts dissipate by the inverse square law, it's completely false to say that (for example) a an efficiency of 0.001 watts at one mile equates to 1 watt at 1000 miles.
If I wanted to break this 'record' I would simply replicate the experiemnt from a distance of 273 miles (half the distance) where I could pick up the signal with 1/4th the required signal strength (inverse square law) and suddenly I have a 'record' of 26,935,960 miles per watt! Heck, if we put the transmitter on the same circuit board as the receiver I could create an 'efficiency' that would let me contact quasars with a hamster wheel.
Bah.
Kevin Fox
Sure, to most people, amateur radio is more of a hobby than anything else. But every hour I work other stations, every hour I speak on the radio, every hour I spend operating my equipment, makes me a better operator as a whole, and more importantly makes me a more effective operator in an emergency.
Conversely, If I have to constantly look up a certian function, or if I'm so nervous I can't compose a coherent message, then in an emergency I will probably not be an effective operator.
So, you see, as with any other skill, the more you practive, the better you'll be. It's unlikely, but I'd much rather be prepared to use it.
The U.S. government initially only offered 15 million in aid, but then public outcry over Bu$h's greed and lack of compassion caused them to raise it to 35 million. When that didn't shut them up, the ante was raised to 350 million. Still less than we spend in a day of "liberating" Iraq.
I think there's something romantic about it that draws geeks towards its coils
Personally I find the capacitors to be that much more erogenous. Especially when they're discharging.
I also like it when they resist a little.
A signal with a wavelength of 1 meter would be a bit below 300 MHz, which is nowhere near the visible spectrum. Laser wavelengths are typically specified in NANOMETERS.
Remember "News for Nerds, Stuff that Matters"? Help make it a reality again! http://soylentnews.org
Shut up, dirty hippy. You lost.
love the stuff
http://www.arrl.org/news/features/2004/12/
and so do most young people
I remeber reading a figure of around 20W for a brain during waking hours and around 10W during sleep. Furthermore the circulatory system can only provide ~18W. We require sleep to build up the energy stores to make it through the day.
Sleep is brain food!
Keep repeating that until you believe it. Or get the facts. The initial $15 million was, just that, initial. When the extent of the damage was realized, it was raised, then raised again.
Do you think Japan pledged $500 million the day after the event? They did not.
Let's examine your retarded statement - Bush (your use of a dollar sign instead of the letter 's' is so original, clever and inventive it should win a Pulitzer) cannot be re-elected. Why should this 'greedy, heartless, stupid, lying, evil, evil man' then care about public outcry?
After all, a public outcry didn't stop him from liberating (no quotes necessary) Iraq.
You may now return to your blind knee-jerk hatred.
GWB didn't lie about WMDs; the media lie about WMDs. What Kay's interim report actually says is rather different than what SeeBS tells you it says.
Speaking of Bass, someone else on the list:
"K4EB Larry Junstrom Bass Guitar player for the rock group 38 Special;"
and seperate the ham from the spam.
Well, the hams and the String Theorists...
I was at the dinner table meeting my wife-to-be's (we've since married) cousins. One of them was a Harvard educated Ph.D physicist who had taught at Oxford (or the other way around...) I was a physics dropout, so of course I was incredibly pleased to meet him, and wanted to find out his specialty. (Mine was gonna be atomic spectroscopy before I quit. I read the Feynman lectures and had a first pass through real quantum, I'm thinking I could maybe keep up.)
"So William, what, ya know, what did you do your dissertation on?" I asked, as politely as I could.
"Oh, William does String Theory," announced my mother-in-law-to-be over her best china. Everyone else at the table gives the obligatory geek acknowledging sigh: "Wow, that's so deep we'll never understand it so please don't explain it to us."
So as that is hitting the table I'm blurting out "And they gave you the Ph.D. for THAT???"
Fortunately, the family could tell from his laughter that it wasn't a big scandal....
I'm about 1800 miles due west of Wappingers Falls. There are the great plains between us and I can climb the east side of the Rockies, but I don't know enough about radio wave propagation and the mountains around Wappingers Falls to know if it would be possible for me to hear the signal. Does the majority of the signal get bounced back from the atmosphere, or do I need to be east of the Alleghenies (like the receiver in the article)?
I am knowledgeable about radio waves in theory (I worked with satellites), but not so much about the practice of bouncing them off the different layers of the atmosphere.
HIV Crosses Species Barrier... into Muppets
It's jigawatt, not jiggawatt...
Just nitpicking
What kind of unit is miles per watt? I could see watt per square mile, or preferably watt per square meter.
If 80 meter radiation penetrated the ionosphere, the detection at a range of 880 km would be about 5*10^-17 W/m^2. I'm fairly sure 80 meter bounces both from the ionosphere and the earth itself, which results in some amplification over the inverse square law value.
In contrast the detection threshold for SETI@home is about 5*10^-25 W/m^2, or a factor of 100 million smaller.
Support SETI@home
There've been a few articles about geocaching, although I haven't seen anything about it in a while.
The company on Slashdot? There's some very insightful and witty people on slashdot, but you have sift through a lot of trolls, wanks, and freaks to find them. Of course, the trolls, wanks, and freaks are interesting in and of themselves. You definitely get exposed to new viewpoints, opinions, and ideas here.
I love it. They win elections by the truckload, but they still can't win a single debate.
Ahem...
BFE == Butt Fuck Egypt == middle of nowhere.
HTH, HAND
"Listen: We are here on Earth to fart around. Don't let anybody tell you any different!" - Kurt Vonnegut
Awesome reply, I would have added you to my friends list.
Wrong. Handhelds are FCC capped at 600mW. Most models these days though max out at 200mW due to closer cell locations using the 1.9GHz band. Old bag phones and installed mobiles were FCC limited to 3W.
What people do not realize though is that the Rx amps in the cellsites are making up the pathloss with 100-130db of rx gain. Systems that use CDMA control the phone's output power. The closer you are to the cell, the less power your phone is "told" to tx. The further away, the opposite. This power control also helps cut down on interference for all nearby mobiles that are tx'ing on the same channel.
Which sounds impressive until one considers that omni-directional sending/receiving power calculations work on an inverse square, so the stat is bogus. FYI: Radar works on inverse 4th, just like the flash of a camera.
Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves.
... in "miles per watt" anybody can beat this "record" pretty much anytime.
As many people have mentioned, the unit chosen is stupid. It is not about nitpicking, the unit has no meaning: this guy could easily beat his own record, not by going into space but simply by sitting half as far, or (even better) right next to the transmitting station. Indeed, all things being equal (hardware used, the ham's ear), the chosen measure increases linearly with the inverse of the distance, and more if the fall-off is higher (usually 3 or 4 in "real life").
As many people mentioned, power fall-off is inverse-square of distance in free space. That means that if the guy had stood half as far, all other things remaining equal, he would have received four times as much power. He could have then halved the transmitted power, he would still have received twice the power as in the reported experiment (making things easier for him to hear). But because the power halved and the distance halved in the process too, the "measure" of distance per power didn't change.
Is this a joke by radio amateurs trying to get the media or Slashdot to publish stupid claims?
In my amateur radio days, I was a very popular conversation - I had a small 5W radio, and I built my own di-polar antenna, I was in Nuuk (capital of Greenland), and I had conversations with southern Brazil, Japan and others - I talked to a lot of people in the UK, and they had trouble believing that I was in Greenland - They said that it sounded like I was in their back yard with a 50W radio ;) ;) ;)
They were all VERY happy to receive my QSL-card
Oh, if anyone remember me, I was 45SR101
Any technology distinguishable from magic, is insufficiently advanced.
What's all this about hams? Christmas was soooo last year...
There are approximately 250 mice to the gallon. --from an old "Life Is Hell" calendar.
Can some one please point it out on a map please.
... the only problem with having mod points for this article and comments is that I don't know enough to tell which ones are informative and which ones are trolls.
What about the Pioneer and Voyager probes?
They're at/near the edge of the Solar System and transmitting at 20 watts, or so, if memory serves.... I also don't think the receiving antennas are 1,000 feet long, either, although they're more expensive.
They've also been transmitting under their own power for about 30 years continuously, or something like that?!?
That's quite a bit better than this example, wouldn't everyone agree?
One of the Voyagers is about 8.5 billion miles from Earth and they only use a 20 watt transmitter. That puts them in the 425,000,000 mile per watt range.
There are masers, which operate around the 24 GHz (1.25 cm) microwave band.
Just wondering...has anyone heard of spam via ham?
More power allows you to last longer and finish your emission!
Libertas in infinitum
nasa spacecraft easily achieve ratios better than that (using satellite dishes, though)
Forget the radio just purchase a honeybaked ham and talk to it instead
What the fuck's K1, is that a movie or something?
http://www.commaecho.com
How do you measure +/-0.0000001 W.
Or is a 4 Watt pulse of 0.00001 sec also OK
Damien Fontaine
You are probably right about the Voyager using less power per mile (in so far that unit makes sense anyway), but a big difference is the noise.
Space is rather cold. When listening to space ships, with these gigantic parabolic dishes, you pick up little noise so the signals can be very weak. Here on earth there is a lot of man-made noise (depending on the frequency you are using) and also thermal background noise because the earth is hot compared to space. (I wrote a fairly easy to grasp article on this topic)
I am still impressed bij this guy.
Z
... what is it in libraries of congress ??
Also, your math is wrong. Omnidirectional signals degrade with distance cubed, not squared
No way! Onmi signals (power) decay with distance squared. Field strength decays linear with distance.
and focused linear signals don't degrade at all, in theory (think perfect laser). In practice of course perfectly focused signals are impossible. Also obstacles in the signal's path (such as the atmosphere) degrade the signal, but not necessarily with a simple polynomial function of distance.
I have the feeling you don't know what you are talking about. 'Focused signals' do not exist at large distances. Any radiating structure (a dipole, a dish, a laser... anything) may have a well contained near field, but at a large distance all of them follow the square law. This 'perfect laser' doesn't exist, even not in theory. Just try to imagine what would happen at the edges of the beam. In practice a laser beam (aka gaussian beam) has a gaussian profile, and a gaussial far field. Admittedly, 'a large distance' is somewhat vague, but clearly after 20 miles (as in the example) you are in the far field.
The GP was completely correct about the example, and 'better results' means a better receiver, as it is able to pick weaker signals out of the noise. Miles/watt is indeed a crappy unit, afaik.
Z
We have used this same strategy to pick up converstations around the glode here at Echelon for years. Oops, I wasn't supposed to say that. Forget you ever heard that.
It's not how big your watts are,
it's how you use them...
Square Law be dam*ed! Thou art wrong!
Things would be good if the wave propagated "in free space". But it ain't. At the frequencies they used the earth acts as a waveguide-- admittedly a very multi-mode waveguide, but a waveguide.
Power doesn't leak into space, it bounces off the ionosphere and earth, and therefore disperses as 1/d, until it gets to the other side...
So the kilometers-per-watt is the most logical.
I'd be tempted to agree with you, but your post only had a comment-ID to user-ID ratio of 18.36, so what do you know?
So throw away the microphone and use Morse! That way, I can play with the radio even when I'm home sick with bronchitis (honest, boss! ask the doctor!).
Maybe of tech but extremely useful in times of emergency and disasters to help save lives worldwide, even in places like Sri Lanka.
N.P.
Milwaukee, WI
Ham radio is still very useful. Think of what you are using to read this page right now, you have ham radio to thank for discovering and improving much of the technology that goes into a computer.
Ham radio is still at the forefront. I don't see anyone else using EME, or watts in the single digits or less to communicate across oceans.
... and it's worse than *that*. When's the last time you tried CW over a repeater?