Decibels Made Easy

Decibels Made Easy (Without Logarithms)by Bruce Spratling, Jr.

Suppose your station has a transmitter that puts out 50 watts of power, a feed line that loses all but 40% of the power, a duplexer that loses half the power, and an antenna that produces enough gain to make the signal 4 times as strong as a dipole antenna. To find the effective radiated power of your station you need to multiply 50 watts times .4 (feed line loss) times .5 (duplexer loss) times 4 (antenna gain) = 40 watts.

Rather than multiply all these factors together, someone decided it would be good to represent them in a way that allows us to add them. An increase of a factor of 10 is defined to be a 10 decibel increase. Decibels are abbreviated dB. Two 10dB increases produces a 20dB increase, because we add decibel increases.

Two increases by a factor of 10 results in an increase of 10 X 10 = 100; therefore 20dB = 100. Three 10dB increases is 30dB, which is 10 X 10 X 10 = 1000.

Because we want to be able to add the dB increases, 0 dB is a factor of 1. Multiplying something by 1 does not change it, just as adding 0 to something results in no change.
Decibels       0         10         20             30
Factor           1         10        100          1000
It’s easy to figure out the meaning of 10, 20, 30, 40… dB, but how about decibels less than 10? Note that if we multiply 2 by itself 10 times, it generates the following: 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024.

2 times itself 10 times is 1024, which is slightly more than 1000, which is 30dB. 3 added to itself 10 times is 30, and 30dB is a factor of 1000. Therefore, 3dB represents a factor of (approximately) 2.

Another way to derive that 3dB represents a factor of 2 is this: If we add 3dB to itself 3 times we get 9dB, which is less than, but close to, 10dB. If we multiply 2 times itself 3 times we get 2X2X2=8, which is close to, but less than 10. This is good because 9dB should be less than 10 (since 10 dB is 10). We have to multiply 8 by 5/4 to equal 10, and we have to add 1dB to 9dB to equal 10dB. Having 3dB = 2 will work if 1dB = 5/4.

Does 1 dB represent a factor of 5/4? If we apply 1dB 3 times, we’ll have 3dB, which = 2. (5/4)X(5/4)X(5/4) = 125/64, which is close to 2. Therefore, a 3dB increase represents a 2 times increase, and 1 dB represents an increase of 1.25.
6dB = 3dB + 3dB. A 3dB increase is a factor of 2, so 6dB = 2 X 2 = 4. Similarly, 9 dB = 2 X 2 X 2 = 8.

So far we have:
Decibels     0     1     2     3     4     5     6     7     8     9     10
Factor         1  1.25          2                   4            8            10
Let’s consider negative decibels. -1dB changes 10dB to 9dB, which changes 10 to 8. Therefore, -1 dB is .8, because .8 times 10 = 8.
To find 8dB, think of 8dB as 9dB – 1dB = 8 X .8 = 6.4. To find 5dB, think of 5dB as 6dB – 1dB = 4 times .8 = 3.2. Note that 5dB + 5dB = 10dB = 10. Using 5dB = 3.2: 3.2 X 3.2 = 10.24, which is about 10. To find 2dB, use 2dB = 3dB – 1dB = 2 X .8 = 1.6

Decibels                    0       1        2       3       4        5             6         7         8         9       10
Estimated Factor     1     1.25     1.6     2     2.5     3.2           4         5         6.4       8       10
Actual Value              1     1.26     1.58 1.99 2.51    3.16     3.985    5.01     6.31    7.94    10
% Error                   .714   -.944    -.236        .475  .178      -.473      .237    -1.41  -.708     0
You’ll notice from the chart that the results are all within 1.5%.

To summarize the system:
Realize that           3dB = 2,           so 6dB = 4,           and 9dB = 8.
You know the value for 3, 6, and 9dB (2, 4, 8).
To find 2, 5, or 8dB (1 less than 3dB, 6dB, or 9dB), use -1dB = .8.
If you want to know 4 or 7dB (1 more than 3dB or 6dB), use 1dB = 1.25.
To find fractions of 1dB, realize that 1dB represents a 25% increase, so .1dB is a 2.5% increase, .2dB is a 5% increase, .4dB is a 10% increase. (This interpolation method isn’t exact, but it’s fairly close when dealing with such small values).
You can carry this further for hundredths of a decibel. .01dB is one tenth of .1dB. .1dB is 2.5%, so .01dB is .25%. .04 dB is 1%.

An example: Suppose an antenna has a gain of 17.68 dB. How much increase is this? Note that 17.68 = 10 + 7 + .68. A 10 dB increase is a factor of 10. A 7 dB increase is a factor of 5. Therefore, a 17 dB increase is a factor of 10 X 5 = 50. .6 dB is 15%, .08 dB is 2%, so .68 dB is about 17%. 50 X 1.17 = 58.5, so the antenna increases the signal strength by a factor of 58.5, the signal is 58.5 times as strong (the exact value is 58.61).
Another example: An antenna’s signal is 25 times stronger than a dipole antenna. How many decibels is this?

This is actually quite easy. A 10 dB increase is a factor of 10. Because 25 = 10 X 2.5, we still have an increase of 2.5 to account for. An increase of 2.5 is 4 dB, so the total increase = 10 dB + 4 dB = 14 dB (the exact value is 13.98 dB).
Suppose we have an increase of a factor of 30. How many decibels is this? 30 = 10 X 3. To multiply by 10 requires 10dB. But, we need to add the decibels needed to multiply by 3. 4dB is 2.5, but we need 20% more (3 is 20% more than 2.5). 20% is about .8dB, so 30 = 14.8dB (the exact value is 14.77).

Well, that’s my system for decibels, and as promised, I didn’t mention logarithms!

Dead Electrical Dudes No. 9 – DeForest

Dead Electrical Dudes No. 9

This Month’s Stiff: Dr. Lee DeForest
Entered Mortal coil: 26 August 1873
Assumed Room Temperature: 30 June 1961

Dr. Lee DeForest

Dr. Lee DeForest

Dr. Lee Deforest
Father of Radio, Grandfather of Television
“How does this blamed thingy work?”

Okay kids, stop laughing! If you’re not familiar with the history surrounding Dr. Deforest, then rest assured that the monikers below his mugshot were not coined by me. Lee used these very terms to describe himself in his later years as he struggled to remain in the limelight and create some sort of lasting legacy. It was only by the slimmest of margins that the above photograph, or one similar to it, does not bear a serial number on the bottom denoting the booking of someone freshly arrested. To be honest, I had a difficult time remaining objective while researching this month’s Dude, as Major Armstrong is one of my personal heroes. So let’s quit fooling ourselves and drop any pretense of being impartial and fair!

Lee’s colorful life makes for interesting reading. From an early age, Deforest was determined to be successful at any cost, and his dream was to amass a large fortune. In the course of his life he made several fortunes. Lee lost several as well; all due to poor business sense, unwise choices for partners, and impressive legal fees accrued from defending himself from patent infringement and suing others. When Lee died in 1961, he only had $1,250 in his bank account. Here’s a few of the high and low points of Lee’s life:

The Spade Detector:
In 1903, Deforest learned of Reginald Fessenden’s new electrolytic detector for use in radio receivers during a casual visit to the fellow inventor’s laboratory. Lee copied Fessenden’s circuit, modified it slightly, and renamed it the Spade Detector. Fessenden discovered this infringement, sued Deforest, and won. Fessenden was awarded damages.
Invention of the Vacuum Tube Triode:
Deforest modified the diode detector tube in 1906 by adding a third element, which was termed the grid. Amplification of signals many times was now possible. However, the triode tube, or “Audion” as he called it, did not work very well. Additionally, no one understood how it worked, especially Lee.

It took the genius of Armstrong to unlock the power of this new device via the principal of the feedback circuit. Lee resented the younger inventor, and proceeded to sue Armstrong over this perceived challenge. What followed was perhaps the longest patent battle in history, from 1914 to 1934, with Deforest eventually winning the rights to regeneration. While on the stand, Deforest could not describe how the circuit worked in coherent terms. Despite the legal outcome, the scientific community did not recognize the ruling of the Supreme Court, as they believed Deforest had stolen the invention from its rightful owner. After all was said and done, the invention of the vacuum tube triode is considered to be one of the fundamental inventions making modern radio communications possible.

Accused in 1912:
Deforest and his partners Smith, Burlingame, and lawyer Samuel Darby, were accused of four counts of mail fraud and other wrongdoings by stockholders in their management of the Radio Telegraph and Telephone Company. Perspective stockholders were induced to buy into the new company via demonstrations of radio communications with Paris, France. It was later learned that the demonstrations were conducted from a hidden transmitter only blocks away. Smith and Burlingame were found guilty. Upon hearing of his acquittal on January 1, 1914, right after New Year’s, Deforest collapsed in his lawyer’s arms. During his life, Deforest started well over 30 companies, and helped drive each into bankruptcy.

Phonofilm:
Deforest dabbled in movie technology and came up with a method of recording sound on motion picture film in 1920. The audio information was recorded on a vertical strip on the edge. Sound was reproduced by directing a light beam through the strip, where it was detected by a photocell. The variations in the light’s intensity were converted to sound energy, and amplified via the usual methods. This technology is still in use today in various forms. Lee received an honorary Oscar for his invention in 1959.

Four Marriages:
Good ole’ Lee really had a way with the ladies! His first wife was Lucille Sheardown, whom he married in 1906, and newspapers reported that the inventor had won her hand by tapping out love messages to her in Morse Code. The marriage was never consummated, and the couple divorced the same year. In 1907, he married Nora Blatch, who was probably every bit as smart as Lee. Deforest refused to accept her as a partner in his research and business dealings, and she subsequently divorced him after bearing a child. In 1912, Lee wed pretty opera singer Mary Mayo, and stayed with her for 15 years, despite her being an alcoholic. They had two children together, but one died at birth. Finally, Deforest married 21 year old actress Marie Masquini in 1930. Marie stayed with the crotchety old inventor until his death. She apparently was the love of his life and a good woman, tending to Lee tenderly in his final days.

Deforest thought of himself as the Father of Radio, and wrote an autobiography under the same moniker in 1949. As an experiment, he had a letter mailed to Hollywood, California, where he resided, with only the words “Father of Radio” on the envelope. The letter was returned to the sender with “addressee unknown” stamped on it. During an episode of “This is Your Life”, Lee was also hailed as the “Grandfather of Television”. Lee also tried unsucessfully to convince Marie to write a book about him: the prospective title would have been “I Married a Genius”. Talk about gall!
Deforest’s life story is replete with tales of controversy, envy, avarice, brilliance, culture, and romance. The reader is encouraged to research further. I apologize if this particular essay ran a little on the long side.

73, Philip Neidlinger, PE KA4KOE

References and Tidbits:
Empire of the Air: The Men Who Made Radio, Tom Lewis

The Complete Lee Deforest Web Page. URL http://leedeforest.org

Biography of Deforest, PBS. URL http://www.pbs.org/transistor/album1/addlbios/deforest.html

 

Dead Electrical Dudes No. 8 – Morse

Dead Electrical Dudes No. 8 by Philip Neidlinger (KA4KOE)

This Month’s Stiff: Samuel Finley Breese Morse
Entered Mortal coil: 27 April 1791
Assumed Room Temperature: 2 April 1872Morse1

In Memoriam: Sam Morse
I decided to do a short essay on Sam Morse given the recent turn of events. I was all set to write you good folks an article on Ampere this time, but alas, it was not to be. Just think, if Sam’s life had turned out a little bit differently, there would not be a system of communications referred to as “Morse Code”, which is a misnomer anyway. The system of dots and dashes may have been invented by someone else and called Johnny Code, or Algernon’s Code, or Fred’s Code, or Old Code (I love rhymes). In my opinion, the code was so simple that it was bound to have devised by some other lad or lass, and we’d have their sepia portrait at the top of this page instead. I like this picture. Instead of holding a book like our dearly departed Count Volta, Sam is holding a telegraph tape. Why isn’t he looking at the tape? Perhaps he is gazing off in the distance contemplating the future. Who knows? Whimsical speculation on your part is highly encouraged in the maelstrom of postings this article is sure to set off. Who was Morse, the man?

Samuel Morse was born in Charleston, Massachusetts, near Boston. Like many an extremely bright youth, Sam didn’t appear to have any direction in his college studies. He was basically a good kid, and wasn’t prone to wild partying, like our friend Ohm. I suspect that some of his father Jebidiah’s inevitable lectures, while Sam sat on his knee, on morality had something to do with it, as the old man was a preacher. As it was, his parents were not happy with the young man’s penchant for painting. Actually, Sam was quite good at it, and was highly respected in his skills. During his college years, he was fascinated by lectures he attended on the groundbreaking subject of electricity. As chance would have it, in 1832 Sam heard about a new invention, the electromagnet, while sailing back to the good ole’ United States after conducting art studies in Europe. A “Eureka” moment occurred, as Sam believed that the invention could be developed into a means of communication. Perchance if Sam hadn’t overheard that conversation, he would’ve died a poor artist.
The idea of an electric “telegraph”, however, was not new. A competing system utilized a system of many wires and a needle pointer mechanism. The needle would rotate to the letter “a” for instance, when the associated inputs were set. However, Morse’s system utilized only a minimal number of wires. A sequence of long and short circuit closures was assigned for each letter and number; a code, if you will. After further development with the assistance of a couple of partners, Morse applied for a patent in 1837. The new invention caught on rapidly. By 1843, with federal funding, telegraph lines were installed between Boston and Washington, DC. In 1844, his now famous message, “What hath God Wrought”, was transmitted by Morse himself between the two cities.

Sam’s system used an electrically-driven needle to mark the long and short dashes on a moving strip of paper, where they could be decoded. However, much to Morse’s incredulity, telegraph operators soon gained enough skill to the point that they could translate the sounds of the electromagnet clicking directly in their heads, and write the letters down as they were sounded out. A common misconception is that Morse’s code is the same code that is currently in use today by hams worldwide. This is not true. Although they share similar characters, there are significant differences. The International Morse Code retains his name to honor the inventor.

In his later years, Morse was married a second time in 1848 to a cousin and begat more children in addition to those begat from his first marriage. He was quite the philanthropist. Sam gave generously to the art programs at Yale and Vassar Universities, and others, and helped out young artists whenever he could. The wealthy inventor died in pneumonia in 1872 while in New York City.

Philip Neidlinger, PE KA4KOE

Dead Electrical Dudes No. 7 – Hertz

Dead Electrical Dudes No. 7 by Philip Neidlinger, P.E. KA4KOE

This Month’s Stiff: Heinrich Rudolph Hertz
Entered Mortal coil: 22 February 1857
Assumed Room Temperature: 1 January 1894

Heinrich Rudolph Hertz

Heinrich Rudolph Hertz

Heinrich Rudolph Hertz
Perhaps the burning question on my mind is why did a lot of the early electrical pioneers sport such interesting beards? Put a rifle in the picture and I can just imagine Heiny walking out of the piney woods after distilling a few hundred gallons of ‘shine.
As you may recall, the existence of electromagnetic waves was predicted mathematically by James Clerk Maxwell and was discussed in the first of this series of irreverent articles. Mathematicians, physicists, and scientists will, on occasion, develop elegant formulae that don’t amount to much except to illustrate some arcane concept with no practical application. However, such was not the case in this particular instance. Heiny took Maxwell’s headache-inducing formulae and proved that they did, in fact, describe a natural phenomenon.

Hertz was born in Hamburg, Germany. At an early age it became apparent that the boy was scientifically inclined. Young Heiny enjoyed building instruments of various types in the family workshop. Hertz began his formal education in 1877 at the University of Munich where he studied engineering. Only a year later, Hertz abandoned engineering (blasphemy!) and began his study of natural sciences at the University of Berlin, studying under Helmholtz and Kirchoff (sound familiar?) where he earned his Ph.D, with magna cum laude honors. His mom must have been a very proud woman! A topic of intense interest in the scientific community at the time was determining whether or not Maxwell’s equations were valid. In 1883, the young scientist also directed his attention to this course of research.

In 1887, Hertz conducted his now famous experiment in which two antennas were placed a few feet apart. The first part of the device consisted of essentially a crude spark gap transmitter connected to the first antenna. The receiving antenna was a loop with a couple of electrodes on the wire ends placed very close together. Hertz activated the transmitter and it generated sparks. Sparks were also seen leaping across the electrode gap at the receiving antenna. Further experiments were conducted in which it was determined that the invisible waves could be reflected and refracted in a manner similar to that of light waves, and finally that light waves were also electromagnetic in nature. Maxwell’s theories were finally vindicated eight years after his death! Hertz’s findings were published in 1892 in his book, Untersuchungen Ueber Die Ausbreitung Der Elektrischen Kraft (Investigations on the Propagation of Electric Energy).

Hertz Apparatus

Hertz Apparatus

Mockup of Hertz’s Classic Experiment
Unfortunately, Hertz died young at the age of 37 from blood poisoning. Associates and friends remember the professor as amiable and modest, and people seemed to be naturally attracted to him. In his honor, the unit of frequency measurement, the Hertz, was named after him.

A young Italian boy read about Hertz’s experiments and it galvanized his attention. I’ll give you three guesses who that boy was!

Philip Neidlinger, P.E. KA4KOE

References: The Spark Museum, http://www.sparkmuseum.com/

Empire of The Air DVD

Empire of the Air DVD – A film by Ken Burns
Narrated by Jason Robards. Running time 120 minutes – Colour/B&W
A PBS Video ISBN: 0-7806-4057-8
Empire of The Air

Reviewed by Lee Jennings ZL2AL

For 50 years radio dominated the airwaves and the American consciousness as the first “mass medium” This film by Ken Burns examines the lives of three extraordinary men who shared the primary responsibility for the invention of radio and it’s early success, and whose genius, friendship, rivalry and enmity interacted in tragic ways. It is the story of Lee de Forest, a clergyman’s son who invented the “audion” tube; Edwin Howard Armstrong, a brilliant withdrawn inventor who invented, regeneration, oscillation, the the superhetrodyne receiver and finally the FM:technology we know today and David Sarnoff, a hard driving Russian immigrant who created the most powerful communications company on earth.

The video portrays these three almost dysfunctional pioneers who plotted, schemed and invented the technology which changed the communications of the world. It also tells the story of giant egos, jealousy and epic courtroom battles that consumed them to the point of multiple marriages and divorces, bankruptcy and suicide. There were of course many other inventors of radio around the world. Although this is a story from an American perspective it doesn’t diminish the drama and intrigue of the era. If you thought that Stephen Job of Apple and Bill Gates of Microsoft had a dustup you can appreciate the acrimony of these pioneers as they waged legal war with each other over their inventions and patents. While they spent time in the courtroom, David Sarnoff bought the licences for their inventions to make a fortune and become the most powerful media man in the USA owning both RCA and the NBC Broadcasting network. Incidentally, David Sarnoff was also an amateur radio operator.

The wonderful black and white still photography and colour clips of the early television era paint a vivid picture of the age. Interviews with prominent family members and early broadcasters fill in the backgrounds of these men. I was amazed to learn that Lee de Forest’s dream of broadcasting speech and music to the masses was pinched by the Canadian Regenold Fessenden who beat him to it by one year. Fessendon had General Electric build him a steam-powered alternator with enough poles to produce a carrier of about 80 KHZ. His modulator was the carbon microphone element from a telephone in series with the field coil. It is thought that when his steam turbine was running at maximum, his generator may have produced as much as 100 KHZ (UHF). On Christmas Eve of 1906,

Fessendon tried out the setup on an island just off the coast of Virginia. He and a friend spoke Christmas greetings to anybody who was listening, played a violin, and frequently gave out an address to which people could write if they heard the broadcast. It probably sounded terrible, but they got cards and letters from people all up and down the East Coast. It is said that people used to listening to the static crashes and buzzing CW signals from spark transmitters thought they were losing their senses when voices and music began to be heard. There were a few steam-powered RF alternators built in the world, but vacuum tubes were discovered around 1907 or so and electronics as we know it was born.

One two minute film clip showed about 12 well dressed gentlemen with bow ties in front a microphone creating the live sound effects for a “western” drama. Absolutely hilarious! Amateur radio is not mentioned in detail but the magnificent towers and radio antennas that were constructed back in those days are a wonder to behold. Marconi’s place in radio history is preserved and the sound and power of a fully operational rotary spark transmitter is awesome! Cutting edge technology between about 1885 and 1920 was to put a tuning coil on the output of the spark gap and to put the gap in to a chamber filled with hydrogen or some other substance and devoid of air so that a hotter spark could be made. Sometimes, the operator got a little too much air in the chamber by accident and the hydrogen would ignite, blowing the whole thing sky high, but that was just an occupational hazard of keeping in touch by wireless in those days.

I watched spellbound for two hours as the drama unfolded. The DVD from Amazon www.amazon.com at $18.00 USD over the internet and the shipping time is about 6 days from the USA. It was originally produced for the PBS (Public Broadcasting System) in the USA for running as a two hour documentary over a few weeks. It is well worth purchasing and would make an excellent video for club use.

Dead Electrical Dudes – No. 6 – Volta

Dead Electrical Dudes – No. 6

This Month’s Stiff: Count Alessandro Giuseppe Antonio Anastasio Volta (whew!)
Entered Mortal coil: 8 February 1745
Assumed Room Temperature: 5 March 1827Volta

“Signore Artist, How long must I hold up this book?”

I look upon these old posed portraits with skepticism. By that, how long did Mr. Volta have to hold that book for this painting? Perhaps Volta’s friend and contemporary, Mr. Luigi Galvani, b.k.a. The Frog Torturer, would have gladly offered to shock his biceps to help with those nasty muscle cramps. Anyway, I digress…

Every time you fumble around in the dark during a power outage, cursing because the flashlight doesn’t work, or are stranded because the darn car won’t crank, or lose all the memories and/or operating parameters in your HF radio’s volatile memory, or you are simply caught flat-footed on Christmas morning as your child cries because his new Super Destructor Evil Doom Machine is only a piece of inanimate plastic, its all because we have come to rely on a relatively ubiquitous piece of technology referred to technically as the voltaic cell. But, almost 200 years ago, this invention literally and figuratively shocked the scientific world (I apologize, this was too hard to resist!).

Signore Volta was born of nobility. At the age of only 14, young Alessandro set his life’s course when he decided his career would be in the field of physics, with an emphasis on electricity. By 1778, the young scientist had isolated methane in the laboratory. He should have visited a nearby cow pasture, in my opinion, for fresh samples of the gas! Volta also invented a static charge accumulator which is the basis of modern capacitors. Such was Alessandro’s success in his endeavors that he was awarded the Copley Medal by the Royal Society in 1791. Greater things and discoveries, however, were to come.

Back to Luigi Galvani: Volta’s friend had been experimenting with the phenomena of what he termed “animal electricity”. Galvani had inserted electrodes of differing metals into a frog’s legs, which resulted in muscular contractions (in essence, the “frog juice” was an electrolyte). Luigi thought he was providing a path for the natural animal electricity.
Volta read and discussed his friend’s findings, disagreed with Luigi good-naturedly, and investigated further. Volta removed the frog, used alternating discs of copper and zinc, and inserted absorbent cardboard pads between the discs which were impregnated with a suitable solution of salts or acid. In 1800, he stacked many of these discs together, a “battery” of them, so to speak, and was greeted with success. The potential generated by only 20 of these discs was enough to inflict pain.

Napoleon Bonaparte requested a “command performance” of Alessandro in 1801 for a personal demonstration of the device. So impressed was the potentate with the “pile of discs” that Volta was eventually made a Count. This invention is also referred to as the voltaic pile.

For Volta’s work, the unit of electromotive force, the VOLT, designated by either the symbols “E” or “V”, was named after him.

Philip Neidlinger, P.E. KA4KOE

Dead Electrical Dudes No. 5 – Ohm

Dead Electrical Dudes No. 5

This Month’s Stiff: Georg Simon Ohm

Entered Mortal coil: 16 March 1789
Assumed Room Temperature: 6 July 1854Ohm

Georg Simon Ohm

One of the favorite movies of my misspent youth was National Lampoon’s Animal House. In this film, we see fraternity boys carousing, drinking, womanizing, gambling, and generally not taking anything seriously. Not surprising is the fact that most of the boys have abysmal grades, and that their fraternity has been placed on “super secret” probation. Georgy would have fit right in. Ohm’s father, Johann, was a self-educated working class man, i.e. blue collar, who had apparently busted his chops getting Georgy into Erlangen University. The old man was fed up with rumors of his son’s excessive dancing, ice skating, and pool playing. After only three semesters, Georgy was pulled out of school and sent to Switzerland where he more or less had to grow up.

What followed after this enforced leave of absence from Erlangen was a series of unsatisfying teaching posts as young Ohm drifted through life. All he wanted was a full professorship at a prestigious institution. Ohm further educated himself and conducted independent research while holding a teacher’s position at the Jesuit Gymnasium of Cologne starting in 1817. Publishing his research, Georgy realized, would get him that coveted post….and research he did! In 1827, after a considerable amount of labor, head scratching, and experimentation, he published his results in the paper Die galvanische Kette, mathematisch bearbeittet. This was quite a mouthful, even in German (read Mark Twain’s essay, “The Awful German Language”, if you really want to laugh). Anyway, the end result of all that formal written Hun verboseness was

E = I x R     Volts = Amperes times Ohms.

This simple little formula defines all things electrical and electronic. If you don’t know it, learn it, or at least do a little bit of research on your own. I can’t do everything for you kids, okay?

Unfortunately, this electrical thunderbolt out of the blue went largely unnoticed, and Ohm’s theory was greeted with less than rampant enthusiasm from his professional peers. In 1841, the Royal Society awarded Georgy the Copley Medal, acknowledging his contributions in electrical research. In 1852, Ohm achieved his lifelong dream and became the Chair of Physics at the University of Munich. The Reaper had the last laugh as poor Ohm only got to enjoy the fruits of his labor for two years before being mowed down by the aforementioned Reaper’s scythe in 1854. Poor Georgy!!!!!

Ohm’s Theory is now Ohm’s Law. Learn it. Live it. Don’t ever forget it!!!

Philip Neidlinger, PE KA4KOE

Dead Electrical Dudes No. 4 – Marconi

Dead Electrical Dudes No. 4

This Month’s Stiff: Guglielmo Marconi
Entered Mortal coil: 25 April 1874
Assumed Room Temperature: 20 July 1937

Marconi

Maestro Marconi

Now, in my esteemed opinion, if you haven’t heard of Guglielmo Marconi, then you should mail forthwith your amateur radio license back to the Friendly Cookie Company (FCC), with a letter of contrite apology addressed to the honorable Mr. Riley Hollingsworth, K4ZDH, Special Counsel for Amateur Radio Enforcement. At the very best, you may be spared an encounter with the dreaded Wouff Hong (a terrible tool used for dealing out punishment to poor amateur radio operators). To put it simply, Marconi fielded the first practical radio communications system. GM’s investigations were spurred on by the news of the success of Heinrich Hertz’s experiments proving the existence of radio waves as predicted mathematically by James Clerk Maxwell.

GM began his experiments in Pontecchio, Italy on his rich Daddy’s estate in 1895, aided by his brother. Marconi’s DX was an astounding 1.5 miles, a feat rarely accomplished by the memorable Radio Shack CB Channel 14 100mW walkie talkies sold to hapless young waifs more than a half century later, powered by the ubiquitous 9V rectangular battery (great for tingling your tongue, by the way — neat trick to try on little kids …heh heh! Evil grin!). Heady stuff, this was. Marconi determined that if he grounded his radio apparatus, performance was dramatically improved. Imagine that! Further experiments and improvements extended the range to 12 miles in 1900, under the auspices of the newly formed Marconi Wireless Telegraph Company Limited. Over the course of 5 years, the Maestro increased the range of his gadget a phenomenal 10.5 miles! How many of you can match this feat of engineering?

In 1901 Marconi finally got his act together and transmitted the letter “S” in Morse code between Poldu, Cornwall England and Newfoundland, a distance of 2100 miles. Note that the transmitter utilized was a spark gap type. If you’ve ever seen a high power spark transmitter in operation, it is a treat, since the massive static discharges are spectacular.

A little known fact is that the letter “S” (di di dit) was used, as the transmitter would have been damaged by the longer arc duty cycle encountered by sending dahs!!!!
GM carried on with further radio commercial ventures that were a financial success. David Sarnoff, who would later become the head of RCA, started out working for Marconi’s company. Did you know that in the early days of Sarnoff’s career, he delivered flowers to Marconi’s many mistresses? Talk about pleasing the boss!!!

Philip Neidlinger, KA4KOE