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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.
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
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
Is it only me who considers HAM, and radio comms in general as the foundation behind Internet.. after all be it air and EM radiation or good old copper, only difference is how you use it to get some data from point A to point B.
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even TCP/IP would theoretically work using smoke signaling, it would be slow, but it can be done
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.
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
2500 kcal * 1000 cal/kcal * 4.184 J/cal = 10.4e6 J/day
1 J = 1 Watt*second, so:
10.4e6 Watt*seconds/day * 1day/86.4e3seconds = 121 Watts
or 1 Watt ~ 20.7 kcal/day
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?
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make install -not war
Um, i seem to work for a few 100kW @ 1500ft radio stations. The absolute local stations in BFE are maybe 10-20kW, but i guarentee there's stations out there who can be heard in places they really shouldn't be. (WLS-FM for instance is 175kW blasting the entire midwest) Believe me, height matters greatly.
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.
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?
Many people have made the comparison to the internet or other wireless technologies. There may be some relation if your only purpose is to talk over a distance. There is however a big difference. All of the services (internet, phone, cell phone) in use by the majority of people require network support. A ham can communicate with none. In an emergency the phone and network services can be interupted by damaged circuits loss of power or just congestion making it impossible to get a message through. The last communication service funtioning will be the hams. Real life example from a call that I relayed. Power and phones were out in a section of the city and a man's wife collapsed. Luckily he was a ham and grabed his radio. I took his info and relayed to it to the fire department and the paramedics were there withing five minutes.
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
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.
the above story was taken from webskulker or rec.humor and possibly other places.
Yes be creative and pass the funnies along but please give credit where credit is due.