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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!"
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?
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.
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.
it would be like running doom 3 on a 286.
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.
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.
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.
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?
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
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"
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.
My cell phone can talk around the world on it's itty bitty power output.
No, it can't. That is why there are those little bars showing signal strength. You're lucky the newer digital units can get two miles to a tower (where it is then pumped thru an ATM link over a T-1 to the landline network).
Funny, fine. But to whomever modded that post "Informative" needs to go back to school.
-Charles
Learning HOW to think is more important than learning WHAT to think.
It's more like hearing a whisper across a huge crowded stadium.
The listener had really good ears and was able to pick out the code from a lot of background noise, with a really good antenna setup.
/sig
Fully attracted by Milli's characteristic-curves, he soon had his resistance at a minimum, and his magnetic field fully excited. He laid her on the ground potential, raised his frequency, lowered his capacitance, then pulled out his high voltage probe and hit resonance. He inserted it into her socket, connecting them in parallel, then began to short circuit her shunt. Finally, Milliamp cried MHO MHO MHO !
With his plate tube generator at maximum plate dissipation, and her coils vibrating from the excessive current flow, Microfarad soon reached his peak also. They fluxed all night, trying various circuits and combinations, until his bar magnet lost all of its strength. Milliamp tried self induction and self excitation, but it damaged her solenoids. With his battery fully discharged, they were unable to excite their generators any further, so they reversed polarity, blew each others fuses, and went Ohm.
Cheers, Peter, W2IRT