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Amateur Radio Set New World Record, 13 Million Miles per Watt:

from The Beacon Tribune on January 4, 2005
View comments about this article!

Amateur Radio Set New World Record, 13 Million Miles per Watt:

January 2, 2005 – New London, NC

Bill Tippett, W4ZV, of New London, NC correctly copied code word OMAHA from the N2XE beacon transmitting with a peak carrier power of .0000406 watts at 3.5455 MHz on the 80 meter Amateur Radio band. Bill confirmed reception of the beacon at 2328Z, January 2, 2005. The precise distance between the two stations is 546.8 miles, establishing Bill's record reception distance at 13,467,980 miles per watt. Tippett used a Ten Tec Orion Transceiver with a 1000 foot Beverage antenna (named after Dr. Harold Beverage who invented it in the 1920s).

The N2XE beacon transmits from an Elecraft K1 (heavily attenuated) using an 80 meter off-center fed dipole, 45 feet AGL (above ground level). The beacon peak carrier output was measured using an Agilent 8563EC Spectrum Analyzer at 40.6 uW (40 millionths of a watt). The beacon transmits a unique code word each evening. Receiving stations are required to correctly copy the code word in their report. The word is published the following morning.

The N2XE Beacon Project was started in December, 2004 by Paul Stroud, AA4XX, Raleigh, NC and John Ceccherelli, N2XE, Wappingers Falls, NY with the goal of having a little fun and to go where no diminutive signal has gone before. Beacon times and frequencies are posted daily on the QRP-L reflector www.kkn.net/archives/html/QRP-L. Tests will continue on 160, 80 and 40 meters through the end of February 2005.

Commenting on his remarkable success, Bill said "I've spent 25 years on 80 & 160 listening to below noise level signals. There are at least three factors to this stuff: Antennas with good signal to noise like Beverages, a good receiver and the knowledge to use it and an operator with good ears and knowledge of propagation--not to mention patience and persistence."

Beacon station operator John Ceccherelli, N2XE, seemed more exited than Tippett about the achievement, even though it requires almost no effort on his part. "Hey, I have to flip the switch, grab a beer and go watch TV—that’s effort" he's reported saying, adding “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.

For more information, contact Bill Tippett at btippett@alum.mit.edu or John Ceccherelli at n2xe@arrl.org

The Beacon Tribune
Poughkeepsie, NY

Member Comments:
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Amateur Radio Set New World Record, 13 Million Mil  
by KC8VWM on January 4, 2005 Mail this to a friend!
Well.. now do you believe me?

All you need is a 40 millionths of a watt to get out.

Now will ya go downstairs and unplug that floor model amplifier/arc welder before you start dimming the lights on my street and start blowing my breakers again ?

:)
 
Amateur Radio Set New World Record, 13 Million Mil  
by AE1X on January 4, 2005 Mail this to a friend!
This just goes to prove the point that BPL signals will be readable and cause real interference. Ed Hare indicated that BPL uses 27uW in each tone in its waveform. This is only 3dB lower than the power used in this record breaking experiment.

You fellas need to make everyone aware of this fact.

Ken
 
Amateur Radio Set New World Record, 13 Million Mil  
by W8JI on January 4, 2005 Mail this to a friend!
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!!

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.

Higher frequencies behave in a very similar manner, distance and attenuation do not have a 1:1 slope.

One watt at a million miles would be astronomically weaker weaker than one microwatt at one mile! Converting directly into miles-per-watt provides a totally meaningless number.

73 Tom
 
Amateur Radio Set New World Record, 13 Million Mil  
by KY6R on January 5, 2005 Mail this to a friend!
Its all in the receiving antenna system, the receiver, and the operators skill / "ears". Honing your ears / mind to hear a signal that is "hiding" right at the noise threshold (using the antenna / receiver "tools")is a very human part of the equation. Being able to hear "ESP" so to speak.

And I can vouch for the Orion's receiver as far as copying weak signals is concerned. A very fine rig.
 
RE: Amateur Radio Set New World Record, 13 Million  
by W9OY on January 5, 2005 Mail this to a friend!
<One watt at a million miles would be astronomically weaker weaker>

nice pun

W9OY
 
RE: Amateur Radio Set New World Record, 13 Million  
by WA4DOU on January 5, 2005 Mail this to a friend!
What Tom says is true however, to truly understand a fact, it helps to look at it in as many ways as possible. To express it in terms of distance per watt is one of them. It does serve to illustrate that we as amateurs often use much more power than we need to over given paths.
 
QRP power doesn't seem so small any more  
by KT8K on January 5, 2005 Mail this to a friend!
Geez .. I thought I was the "little guy" with my 5 watt HF signal .. now I realize .. I'm QRO!!

Thanks to all who have worked to hear me.

Interestingly, sometimes I have to work to hear a KW station, proving that band conditions (for example)play a MUCH bigger part than output power in a successful QSO.

Good reception & 73 to all de kt8k - Tim
 
RE: QRP power doesn't seem so small any more  
by KE4MOB on January 5, 2005 Mail this to a friend!
"Amateur Radio Set New World Record, 13 Million Miles per Watt"

And then there's Voyager 1, which is 8.7 Billion miles from home....
 
RE: QRP power doesn't seem so small any more  
by N2XE on January 5, 2005 Mail this to a friend!
13 million is a "terrestrial" record I suppose. How does one compete with 23 watts 8.7 billion miles away. Besides, they don't let us Amateurs use Arecebo...
 
RE: QRP power doesn't seem so small any more  
by W9PMZ on January 5, 2005 Mail this to a friend!
Good thing that banks don’t advertise this way, invest a dollar and we will give you $10 (in 100 years…..)
 
RE: QRP power doesn't seem so small any more  
by KZ1X on January 5, 2005 Mail this to a friend!
"Besides, they don't let us Amateurs use Arecebo..."

... umm, actually, that's not *completely* accurate ...
 
RE: QRP power doesn't seem so small any more  
by WA6BFH on January 5, 2005 Mail this to a friend!
No, its not accurate! When I first saw the title of this piece, I thought that it would make reference to some achievement by Ham's in space communication. That would be of interest!

I believe that the MF and HF spectrum has been thoroughly investigated. This was done during and following WW2. Why do we care what the propagation may now show on these bands, can we not find this information by merely looking it up?

Scientific interest on the VHF and above spectrum is wanting! That is the portion of our spectrum that is threatened!

Of course, when I correspond with Hams these days about some compact beam antenna of .047 wavelength aperture size that has better than 11 dB's of gain, I guess I should not be surprised!
 
RE: QRP power doesn't seem so small any more  
by KE4MOB on January 5, 2005 Mail this to a friend!
"Besides, they don't let us Amateurs use Arecebo..."

Actually, I thought it was NASA DSN Goldstone that pulled the Voyager sigs outta the mud...
 
RE: QRP power doesn't seem so small any more  
by N2XE on January 5, 2005 Mail this to a friend!
"I believe that the MF and HF spectrum has been thoroughly investigated. This was done during and following WW2. Why do we care what the propagation may now show on these bands, can we not find this information by merely looking it up?"

To the contrary, it's VHF and up that's pretty well understood. Not that there isn't much to learn there, surely there is.

80 meters is still somewhat of a mystery and 160 meters is, pretty much, a total mystery. They do not behave nor do they respond, like 40 meters and up, to the usual cookbook propagation theory. I suppose that's what makes it so addictive to the low-band DX types. It's not predictable and it ain't easy.

Why do we care? Not sure about you but I care because it's there and it's unknown. Simply human curiosity--nothing more.
 
Amateur Radio Set New World Record, 13 Million Mil  
by KB2HSH on January 5, 2005 Mail this to a friend!
The "thrilling" part is the fact that a Ten-Tec was involved in the process.

...and here I thought working South Africa with 2 watts was a big deal.

John
KB2HSH
 
Welcome /.  
by N8VW on January 5, 2005 Mail this to a friend!
Someone going by the name "DoctorPepper" got this posted on /.. You all can have fun by reading what the /.ians have to say. Much fun.

http://science.slashdot.org/science/05/01/05/2246205.shtml?tid=215&tid=193&tid=14
 
Amateur Radio Set New World Record, 13 Million Mil  
by KF6ZLB on January 5, 2005 Mail this to a friend!
I agree with W8JI that miles per watt is an inappropriate yardstick, and suggest an alternative measure. My reasoning is not based on the inefficiencies of the longer paths. It applies even in free space, without any attenuating reflective or absorptive media:

Even without any attenuating anomalies in the path (that is, say, in free space), power density falls off with distance r by a factor of 1/(r squared). So if transmitter power is increased four times, the distance at which the tranmitter delivers the same signal is only doubled. The miles per watt yardstick gives an undue advantage to the lower power efforts.

A yardstick that would even the playing field, at least in free space, would be miles per square root of watts.

A simple thought experiment shows that power density (watts per square meter) drops off as the square of distance. The power from an isotropic radiator illuminates an imaginary spherical surface surrounding the radiator uniformly. All of the watts are distributed evenly on the surface area of the sphere. A second sphere of TWICE the radius again receives all of the watts, but this new sphere has FOUR TIMES the area. In other words, simply doubling the distance results in a 6 dB decrease in power density, not 3 dB.

Happy New Year,
Doug
 
RE: Amateur Radio Set New World Record, 13 Million  
by AC0H on January 5, 2005 Mail this to a friend!
.0000406 watts.

OK, How do you measure that?
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 5, 2005 Mail this to a friend!
From the article text

"The beacon peak carrier output was measured using an Agilent 8563EC Spectrum Analyzer..."
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 5, 2005 Mail this to a friend!
"A yardstick that would even the playing field, at least in free space, would be miles per square root of watts."

Doug, I agree in principle but I'm not sure the math is right. Since the beacon transmits at a fixed power, the difference is distance. So whatever you do to the demonimator won't change the measure exponentially. I.e. Miles per Watts or Miles per Square root watts still yields a 2X difference for a station twice the distance.

I think it should be miles squared per watt. Then a station twice the distance gets 4 times the number.

Or we can just all agree that as distance increases, it becomes exponentially more difficult.
 
Amateur Radio Set New World Record, 13 Million Mil  
by WA2JJH on January 5, 2005 Mail this to a friend!
sad BUT TRUE, the extrapolation is bogus.There is a big difference between free space and air as well.

This company makes a watch with a built in emergency
beacon. That particular Breitling has a 50mw Tx beacon in it.

They said over 600km range at 121.5 or 243mhz.
Problem is the Rx has to be at 10,000 feet.

Good luck!
 
RE: Amateur Radio Set New World Record, 13 Million  
by KC8VWM on January 5, 2005 Mail this to a friend!
Do we actually know if a reflected signal in the ionosphere is somehow amplified when a signal is propogated through it?

Charles - KC8VWM
 
Amateur Radio Set New World Record, 13 Million Mil  
by W6LX on January 6, 2005 Mail this to a friend!

Congratulations on an amazing record.

In the interest of making sure we have our accuracies all in order, and certainly not to rain on your parade, I just wanted to ensure that good measurement technique was used.

The Agilent 8563EC spectrum analyzer is a good instrument to use to measure power at these levels (40.6 uW is approximately -14 dBm), but it isn't the best instrument to use. The best instrument is always a power meter, but given that we have the spectrum analyzer let's go through an uncertainty calculation to see how accurate this measurement is.

When you make a power measurement with a spectrum analyzer, you usually use the built-in calibration signal on the front panel to calibrate the analyzer. This signal allows you to remove various errors that are present, including RF frequency response, IF gain, log fidelity, RBW switching, etc. These errors add up; you can be as much as +- 3 dB off on this particular model, and that's about par for this type of test instrument.

If you calibrate with the 300 MHz signal available on the front panel, you remove these errors, *as long as you don't change anything to make the actual measurement*. However, to measure the 80 meter signal from your transmitter, you had to change the center frequency from 300 MHz to 3.55 MHz. By doing so, you incurred a frequency response error of +- 1.8 dB (from the data sheet) in that band. In addition, the cal signal itself has +- 0.3 dB of uncertainty, so the total uncertainty is now +- 2.1 dB.

I am hoping that you did not change 1) the resolution bandwidth or 2) the reference level, because by doing so you would have incurred another +- 1.5 dB of error.

I am also hoping that you made all of your measurements with the signal peak touching the top line of the screen (the reference level). If you did not, you incurred another +- 0.1 dB for every dB away from the top line, up to a maximum of +- 0.85 dB.

Anyway, I give you the benefit of the doubt. So your measurement of "0.0000406 watts" could be as much as +2.1 dB higher, or 65.8 uW, or as much as -2.1 lower, or 25.0 uW. Because we don't know which is the case, to be fair we have to assume the higher, 65.8 uW, which would change your miles/watt number by a factor of 0.617. This would put your achievement in the neighborhood of 8.3 million miles per watt, still an impressive number.

Again, congratulations. I am by no means trying to be a stickler, but I did want to point out the inherent inaccuracies present in any power measurement.

Take care.

Regards,

Al W6LX





 
Amateur Radio Set New World Record, 13 Million Mil  
by KF6ZLB on January 6, 2005 Mail this to a friend!
John, N2XE,

Good idea. Miles squared per watt would also work, and is easier to compute. Note that miles per square root of watts is just the square root of your proposed measure. Either way, a larger number represents better performance by the stations involved (most notably in the receiver to extract the signal from the noise, and in the transmission/reception algorithm that makes the extraction of the signal from the noise possible).

Note that the difficulty does not increase exponentially when distance increases linearly, the difficulty increases EXPONENTIALLY when the distance increases EXPONENTIALLY. If the distance increases by 2 to the Nth power, then the power density falls off by 4 to the Nth power, or equivalently, by 2 to the 2Nth power. The "2" in the 2N exponent is due to the square law nature of the problem.

Doug
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 6, 2005 Mail this to a friend!
Al, W6LX,

Thanks! You really do know the 8563! I can assure you that I didn't screw it up too badly. I do change the reference level around to see what happens but at the reference level is where I call it "good". I think I'm +/- 10% from reality.

73,
 
Amateur Radio Set New World Record, 13 Million Mil  
by N0FP on January 6, 2005 Mail this to a friend!
Apparently, the real record remains unrecorded. The real record is 37,878,788 miles per watt! I notified the 160M reflector and Topband reflector the same day. Did it in broad daylight no less.

Using a -60dBm signal, I successfully communicated all the way to my beverage antenna, about 200' away! Do the math. It works out to 38MM miles/watt!

But apparently this doesn't count. Why? Who knows? It's all in fun anyway. But the QRO used to record the 13 million miles is hardly the record miles/watt.

The point is not the record, the point is the measure is bogus. The closer the receiving antenna is to the transmitting antenna, the less power needed. I suspect a very diligent ham could get this up to a light year per watt without too much difficulty. Of course, the difficulty will be in measuring the real watts involved, and measuring the distance with a micrometer...

Nuff said...

Ford-N0FP
ford@cmgate.com
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 6, 2005 Mail this to a friend!
OK Ford, agreed.

W4ZV hold the far field record...
 
RE: Amateur Radio Set New World Record, 13 Million  
by W4EF on January 6, 2005 Mail this to a friend!
W8JI Wrote: >>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.<<<

Making it even more complicated is the fact that as distance between the two stations decreases into the NVIS range, the difference between path length through the ionosphere and the actual map distance between the two stations gets large.

What you need is "miles/weighted watt" where actual mileage is weighted according to some standard model for path loss (like the CCIR model Tom mentioned). For example, 100 uW received at 500 miles, would be equivalent to 8000 miles/watt instead of 5 million miles/watt since it is in 10dB per distance octave slope region (e.g. each 10dB increase in power doubles communication range in that part of the curve, so normalizing 100uW to 1 watt (40dB increase) is equivalent to doubling communications range 4 times (2^4 = 16; 16 x 500 miles = 8000 miles). At 40.6uW and 546.8 miles, using the 10dB/decade rule, that would normalize to 11476.1 miles/watt. That would be believable given the quality of Bill's RX antennas (I could imagine Bill being able to hear a 1 watt VK6 beacon with his setup under extraordinary conditions).

73 de Mike, W4EF.....................
 
RE: Amateur Radio Set New World Record, 13 Million  
by W4EF on January 6, 2005 Mail this to a friend!
W4EF wrote>>>>At 40.6uW and 546.8 miles, using the 10dB/decade rule, that would....<<<<<<<

Sorry I meant to type "10dB/octave" there.

Mike, W4EF.............
 
RE: Amateur Radio Set New World Record, 13 Million  
by KC8VWM on January 6, 2005 Mail this to a friend!

These signals regardless of the measured output power at the transmitter may be supressed or optimized on a variable scale due to atmosperic changes, particulate matter in the air, sunspot activity, weather conditions and even certain angles of radiation reaching the horizon.

Given this vast array of variables and since this measured scale is always variable and ever changing, how does one accurately formulate and equate distances of travelling radio signals measured based on such known formulations which are based on the idea involving the speed of light travelling in a straight line in a vaccuum with no resistance present? Certain path loss models may be calculated to offset these differences however they too may be linited to a fixed and not a variable numeration.

Also If some of these angles of radiation from the antenna reflected are actually exhibiting a measurable gain and a maximized increase in signal reflectivity over the horizon, how is that variable traced and factored into the final equasion of measured distance which estimates the radio signals travel at say 11476.1 miles/watt, when each given mile of that signal travelled is not equal and substatially variable?

73

Charles - KC8VWM
 
RE: Amateur Radio Set New World Record, 13 Million  
by W4EF on January 6, 2005 Mail this to a friend!
KC8VVM wrote>>>These signals regardless of the measured output power at the transmitter may be supressed or optimized on a variable scale due to atmosperic changes, particulate matter in the air, sunspot activity, weather conditions and even certain angles of radiation reaching the horizon<<<<<

Yep!

>>>>Given this vast array of variables and since this measured scale is always variable and ever changing, how does one accurately formulate and equate distances of travelling radio signals measured based on such known formulations which are based on the idea involving the speed of light travelling in a straight line in a vaccuum with no resistance present? Certain path loss models may be calculated to offset these differences however they too may be linited to a fixed and not a variable numeration.<<<

Yep!

>>>>Also If some of these angles of radiation from the antenna reflected are actually exhibiting a measurable gain and a maximized increase in signal reflectivity over the horizon, how is that variable traced and factored into the final equasion of measured distance which estimates the radio signals travel at say 11476.1 miles/watt, when each given mile of that signal travelled is not equal and substatially variable?<<<

You are right on all counts, Charles. My calculation was just an attempt to get a little closer to the right answer and to illustrate the difference between the simple miles/watt calculation and a slightly less simple calculation using weighted miles/watt. All ionospheric paths are statisical in nature. No formula can tell you exactly what the path loss will be at any given moment on any given day. That is why DXers don't get enough sleep, especially topbanders. They stay up all night hoping that they are awake and in front of their rigs for that 20 minute long 3 sigma opening where the path loss to East Shangri-La is 30dB lower than average.

73 de Mike, W4EF.....................

 
RE: Amateur Radio Set New World Record, 13 Million  
by KC8VWM on January 6, 2005 Mail this to a friend!
Well thanks Mike for clearing that up. For a minute there I was thinking it was all carved in stone as reality. I promise I won't loose any sleep over this but it is rather interesting to think about.

I appreciate your insight on this subject and enjoyed reading your post.

73

Charles - KC8VWM
 
Amateur Radio Set New World Record, 13 Million Mil  
by VU2ZAP on January 7, 2005 Mail this to a friend!
I have worked many countries in Europe, Africa & Asia with just 1 milli watt both SSB and CW. These are cold calls and not skeds. To get an callers attention is tough but very rewarding. There should be a milliwatt alley allocated in all bands.

Couple of years or more ago I received a report of 3/3 SSB from W3LPL Frank on 10M. I have not calculated the miles per watt.

I run 2 watts into a 33 db power attenuator. Power cal with HP 435B power meter. 4 El short beam on 10M.

In contrast with 5W QRP, I worked 105 countries in 60 days. It was fun..

73
Raj
Bangalore, South India.
 
RE: Amateur Radio Set New World Record, 13 Million  
by W9PMZ on January 7, 2005 Mail this to a friend!
The statement is misleading because there are gains in the link path.

From:
http://www.cisco.com/univercd/cc/td/doc/product/wireless/bbfw/ptop/p2pspg02/spg02ch2.htm

"
Free-Space Path Loss
A signal degrades as it moves through space. The longer the path, the more loss it experiences. This free-space path loss is a factor in calculating the link viability. Free-space path loss is easily calculated for miles or kilometers using one of the following formulas:

Lp = (96.6 + 20 log10 F) + (20 log10 D)

where

Lp = free-space path loss between antennas (in dB)

F = frequency in GHz

D = path length in miles
"

Calculating Lp,

96.6 + 20 log (.0035) + 20 log (13000000)

Lp = 189dB

Assuming dipole antennas, polarized and oriented in the same direction, the trasmit power being -14dBm (which is easy to measure using a power meter; such as a HP437B), in free space the power at a receiver would be:

Pr = -14dBm + 3dB + 3dB -189dB,

or

Pr = -197dBm

(this is what, 97dB below noise on 80M???)

So to extrapolate 13000000 miles per watt is disingenous............

73,

Carl - W9PMZ
 
RE: Amateur Radio Set New World Record, 13 Million  
by VR2BG on January 7, 2005 Mail this to a friend!
Thanks to W6LX for posting with more detail what I was not able to get through the moderated Topband mail list.

I believe the absolute frequency response tolerance by itself makes a Bird 43 theoretically more accurate.

It is unfortunate that this simple stuff doesn't seem to register & merely bringing it up was an apparent no-no, as it will put other folks off sharing their knowledge - one of the things I appreciate from the some of the amateur mail lists on eHam.net/contesting.com.

Will still take H-P for frequency domain T&M any day (sorry, don't like the new name & reckon the lady from Compaq has Mr H & Mr P turning in their graves ;^), but with any instrument one must be aware of its capabilities, how you are using it & what that means to what it is telling you. Or at least that is what I have learned in the last 13 years using this equipment where I used to work at a satellite earth station.

The whole exercise is fun (not setting things like IPBO on an uplink or acceptance tests on some piece of equipment) & like W6LX, I do not want to ruin folks' enjoyment of it, but the measurement methodology used is a little slack to conclude a record of some sort has been set, IMHO. Tighten that up & then you're on to something... and perhaps to address the propagation variable, why not do something like the NCDXF beacons & drop 10 dB each on each transmission?

It's easy to do, easy to verify & gives the participant the ability to see improvements whilst striving to get down to that next 10 dB step.

73, VR2BrettGraham
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 7, 2005 Mail this to a friend!
Brett, VR2BG wrote--
"I do not want to ruin folks' enjoyment of it, but the measurement methodology used is a little slack to conclude a record of some sort has been set, IMHO. Tighten that up & then you're on to something"

I take issue with that. I used the 8563 because it's a good and accurate instrument to tell me what frequency I'm at and how much power I'm putting out. It could potentially be off +/- 2.1% but it wasn't. That's the worst case possible error assuming they all conspire against you. In reality they tend to cancel (with my unit anyway).

I used precision, characterized Tektronix attenuators to drop the 400 mW output signal to 40uW. I had two 20dB Tektronix attenuators and an HP 8494A step attenuator in the chain. The Tektronix attenuators measured out at 19.99 dB each at 10 MHz. The step attenuator was set to 0dB. That should have produced a an output signal of 40.18uW. The 8563EC measure 40.6uW. That's what I used since it was a tad pessimistic and the 400 mW was determined by an MFJ-872 watt meter calibrated by oscilloscope measurements that could be off as much as +/- 10%. Since it was all lining up nicely, I went with 40.6uW.

After the run was completed, I re-measured the beacon output with the 8563EC and measured 40.6 uW.

I stated earlier that I think the value is within 10% (0.4 dB) of reality but it's clearly much better than that.

My question to you is: On what facts do you base that the procedure was slack? What recommendations would you make given the equipment available to me as stated above.
 
Amateur Radio Set New World Record, 13 Million Mil  
by N2XSE on January 7, 2005 Mail this to a friend!
Let's get crazy and say it was a 1/4 of a watt I'm still impressed.

de n2xse
 
RE: Amateur Radio Set New World Record, 13 Million  
by VR2BG on January 7, 2005 Mail this to a friend!
John, there is one important word that you have included now & not previously: characterized.

That makes things very different.

Otherwise, the spec an on its own is sloppy & many don't realize this. I may have missed that bit of information if it was mentioned earlier & I apologize if that is the case. Nothing untoward meant in my trying to raise the point. QSL?

73 & HNY/HLNY, VR2BrettGraham
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 7, 2005 Mail this to a friend!
Quite all right with me. If I did something stupid (not a remote possibility) I want to know about it. You didn't miss anything, I didn't document the procedure in full.

Many people are asking questions about how one measures a signal in the microwatt range and assume it's difficult. I guess there's lots of ways to do it but it's not that difficult. I figured I provide more detail.

Cheers, 73,
N2XE
 
Amateur Radio Set New World Record, 13 Million Mil  
by WI8W on January 7, 2005 Mail this to a friend!
I am the current Awards Manager for QRP Amateur Radio Club International.

Our club has offered the 1000 Miles Per Watt Award for the past 39 years. I have records of distances claimed from 1966 to the present day.

This post topic has got me interested in updating the database for this award to make sure it is accurate and up to date.

In the process of doing this I have discovered some interesting distance claims in which our club awarded certificates to the participating stations. For example:

A award certificate was issued to JO1XWH and JH1MBQ who claimed they transmitting/received a 50 Mhz signal using a power output of 0.05 microwatts for a claimed distance of 134,200,000 miles/watt. This award was issued on July 16, 1989. The 1000 Mile Per Watt Award number was 1149. This is the farthest distance claim in the records so far but I am still recalculating some old data that was not entered into the records correctly.

A award certificate was issued December 26,1989 to OK1DKW and OK1OFK who claimed transmitting/receiving a 160 nanowatt signal on the 144 Mhz band equivalent to a distance of 87,500,000 miles/watt. Their certificate number was 1177

There are many more that exceed 50,000,000 miles per watt in the records of the award program. Most involve short distances and nanowatt power levels.

We are also investigating a amateur contact from the late 80's - early 90's timeframe that was published in a issue of 73 magazine that claims a distance exceeding 1 billion miles per watt.

Our 1000 miles per Watt awards program is simply for fun and not for any scientific purpose. We have to rely on the data supplied by the claimants.

Our Awards program can be found at www.qrparci.org

73

WI8W


 
RE: Amateur Radio Set New World Record, 13 Million  
by W4ZV on January 8, 2005 Mail this to a friend!
It's been interesting reading all the responses. I agree with the general comments regarding the difficulty of comparing these "records" using any sort of simple metric. The following illustrate the problems with this:

"A award certificate was issued to JO1XWH and JH1MBQ who claimed they transmitting/received a 50 Mhz signal using a power output of 0.05 microwatts for a claimed distance of 134,200,000 miles/watt. This award was issued on July 16, 1989. The 1000 Mile Per Watt Award number was 1149. This is the farthest distance claim in the records so far but I am still recalculating some old data that was not entered into the records correctly."

***Implies 6.71 miles and therefore line-of-sight.

"A award certificate was issued December 26,1989 to OK1DKW and OK1OFK who claimed transmitting/receiving a 160 nanowatt signal on the 144 Mhz band equivalent to a distance of 87,500,000 miles/watt. Their certificate number was 1177."

***Implies 14 miles and therefore line-of-sight.

As others have pointed out, it is a different ballgame when signals are actually propagated via the ionosphere at longer distances. There is also a huge difference in ambient noise background between 3.5 MHz and VHF.

Such "records" are really meaningless to me...I just enjoy the challenge of digging weak signals out of noise...otherwise I would not have been doing it on 80 and 160 the past 25 years.

73, Bill W4ZV
 
RE: Amateur Radio Set New World Record, 13 Million  
by W9PMZ on January 8, 2005 Mail this to a friend!
To calculate link budgets in radio systems it can be shown that:

Pr = Pt * Gt * Gr * wl / ( 4 pi r )^2

where,

Pr = power at the receiver
Pt = transmitter power
Gt = gain of the transmitter antenna referenced to isotropic
Gr = gain of the receiver antenna reference to isotropic
wl = wavelength
r = distance between transmitter and receiver in kilometers

In seems in these "awards" path losses are minimized to allow for the manipulation of transmitter power.

The reality is in some of these "awards"; if you actually trasmitted 1 watt, over the claimed distance you have no hope of recovering the transmitted signal...........

It may be "fun", but it has no reality.

73,

Carl - W9PMZ
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 8, 2005 Mail this to a friend!
"The reality is in some of these "awards"; if you actually trasmitted 1 watt, over the claimed distance you have no hope of recovering the transmitted signal...........

It may be "fun", but it has no reality. "

Where I come from, earth, it gets difficult to separate stations by more than say... 12,000 miles. So you are correct--there's no hope of recovering a 1 watt signal over the claimed distance. But it is fun, not "fun", just plain ol' vanilla fun.
 
RE: Amateur Radio Set New World Record, 13 Million  
by W9PMZ on January 9, 2005 Mail this to a friend!
You missed the point, 1 watt over 12000 miles in the HF spectrum is reality. But you are saying 13 million miles per watt; which is not the same.

Suppose I set up a transmit / receive path that is 1 inch apart, where I run 10^-15 watts. Can I caim credit for 1 watt over 12 * 5280 / 10^-15 or 63 million miles per watt?

Now lets reduce the power even more, by a factor of 1000, 63 billion miles per watt...

and on and on....
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 9, 2005 Mail this to a friend!
Not really because at 1-inch apart, it's all capacitive coupling so you really haven't launched an E-M wave. These analogies with sub-meter distances are really absurd. Let's talk far field radiation at the very least.
 
RE: Amateur Radio Set New World Record, 13 Million  
by W9PMZ on January 10, 2005 Mail this to a friend!
Far field, 10 wave lengths, OK, at 10 GHz that is .3 meters.

Just to clarify, I think that the accomplishment of 500 miles using -14dBm is a very notable achievent. However, you can't normalize the distance to 1 watt because there are other variables in the link budget that need to be considered before a claim, such as miles per watt, can be made.

73,

Carl - W9PMZ
 
RE: Amateur Radio Set New World Record, 13 Million  
by N2XE on January 10, 2005 Mail this to a friend!
Carl, this was done at 3.5455 MHz. 10 wavelengths is closer to half a mile than .3 meters. Band noise is significantly greater at 80 meters than 10 GHz.

I think the claim was 547 miles at 40uW. Lots of folks have done better on 10 meters but this is 80 meters. 13 million miles per watt is a fun number that the non-initiated can understand--That's all. I think most of us are well versed in path loss, reflection loss,inverse square law, what have you.

Then again, the signal may have traveled about 500 revolutions around the globe trapped in some sort of hideous chordal loop. It could happen...
 
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