Mid-Atlantic Antique Radio Club - MAARC

10/28/2026

The Wednesday, October 28th MAARC Facebook post takes us back 100 years in wireless history. But first, who gets Honorable Mention for last Sunday's Famous Names quiz? That would be MAARC members Kent King and John Foell with perfect scores.

On to our post. This one gets it start from three "At The Controls" page posts by Sean Brady. "World Wide Telegraph Transmitter in Rugby, Warwickshire. 'The world's largest and most powerful wireless station. Originally constructed for wireless telegraphy and erected for strategic reasons, it could at a moment's notice broadcast a message so powerful that it would be picked up by almost every ship at sea. It has separate aerial systems pointing at the USA, Canada, South Africa, India, and Australia.'

The first two photographs show the main control table containing all the main control instruments. Initially, the Rugby site utilized high-power thermionic valve (vacuum tube-see third photo) transmitters. At the time of its 1926 opening, it was groundbreaking for relying entirely on thermionic valves rather than the older mechanical alternators or spark-gap technologies common in earlier high-power installations. The primary systems installed at launch and shortly thereafter included:

• The callsign GBR VLF Transmitter: This was the site's flagship 350kW water-cooled valve transmitter. It operated on a Very Low Frequency (VLF) of 16 kHz to transmit global Morse code telegraph and news broadcasts across the British Empire. The high-power valves required continuous water cooling to prevent overheating.

• The Transatlantic Telephone Transmitter: Installed shortly after by Western Electric (later ST&C), this 300kW transmitter operated on a long-wave frequency of 60 kHz. Crucially, it used an early form of single-sideband (SSB) modulation with a suppressed carrier. This marked one of the very first commercial applications of SSB technology, which dramatically improved transmission efficiency for the historic London-to-New York telephone service launched in January 1927.

To supply the extreme high-voltage direct current (EHT) required to run these massive valve systems, the station's "C Building" power room housed heavy-duty, multi-kilovolt DC electrical generators (see fourth photo).

Key History and Milestones

The station was launched by the United Kingdom Post Office with the callsign GBR transmitter using VLF waves that followed the curve of the Earth to reach global ships and British overseas territories. It started the world's first commercial transatlantic voice telephone service in January 1927, linking to Houlton, Maine, with initial calls costing £15 for three minutes.

During World War II, the station switched to specialized telegraphy and military roles, including supporting RAF bomber operations and jamming communications via Operation Corona, a story all onto itself. Launched in late 1943, Operation Corona was a highly successful British electronic warfare and "black propaganda" initiative designed to protect Allied bombers. It worked by hijacking German night fighter radio frequencies to feed N**i pilots false information, directly undermining the Luftwaffe's air defense coordination. The Rugby Radio Station played a critical hardware role in this deception due to its exceptional power and agility.

Operational intelligence began with the RAF "Y" Service at RAF Kingsdown, which closely monitored German radar and radio frequencies. When they identified the specific radio telephony wavelengths being used by Luftwaffe ground controllers to direct fighter attacks, they prepared to strike. Kingsdown sent the active German frequencies via a secure teleprinter link directly to the engineering team at Rugby. Thanks to its versatile high-frequency (short-wave) transmitters, Rugby’s engineers could tune into and broadcast over the exact German frequencies within two minutes. Because Rugby's transmitters were immensely powerful, they could cleanly overpower or seamlessly blend into the real German signals. Using "Ghost Voices", the actual talking was done by fluent, native German speakers—many of whom were Jewish refugees from Germany and Austria who had escaped to Britain and volunteered for the war effort. Speaking from microphones linked to the system, these operators masterfully impersonated Luftwaffe ground defense officers. Sowing "Total Chaos" in the sky, the Allied operators aggressively disrupted German air defense tactics. If a real German controller told fighters to head north to intercept bombers, Rugby's transmitters would instantly broadcast a convincing counter-order telling them to fly south or return to base. Fake controllers frequently warned German pilots of nonexistent bad weather or phony technical closures at their home airfields, instructing confused pilots to land immediately. Such tactics resulted in a "Battle of the Voices". Real German controllers would scream that the other voice was a fake, while the British operators at Rugby would calmly reply that the real controller was actually the British imposter.

Operation Corona premiered with devastating success during a massive RAF bombing raid on the industrial city of Kassel in October 1943, leaving the local Luftwaffe defenses completely scattered and paralyzed. When the German High Command realized their male radio operators were being perfectly impersonated, they switched their ground controllers to women, believing the British wouldn't be able to match the voices. The RAF anticipated this shift; they had already recruited and trained German-speaking members of the Women's Auxiliary Air Force (WAAF), allowing Rugby to seamlessly continue the deception until the end of the war in 1945.

Radio station Rugby expanded significantly by the 1950s to house 57 transmitters across 1,600 acres, making it the largest radio station in the world. It also broadcast the iconic Greenwich time signal ("pips") and served as a vital VLF link for Royal Navy submarines during the Cold War. The GBR service ended in March 2003, and all final transmissions ceased in 2007. The historic 'C' building was preserved and incorporated into Houlton School. The station's 100th anniversary was marked by a special exhibition at the Rugby Art Gallery & Museum. Portions of its historic hardware, such as the massive tuning coil, are displayed at the Science Museum in London.

10/27/2026

The MAARC Facebook post for 27 October provides us some vintage computer history. It comes to us via the "At The Controls" page and author Sean Brady.

"Meet MANIAC, Los Alamos's crazy-fast first supercomputer. Built in 1952, the Mathematical Analyzer, Numerical Integrator, and Computer (MANIAC) performed an impressive 10,000 calculations per second — many times faster than the human "computers" of the day.

MANIAC became an essential tool for science during the Cold War, and in 1956 was the first computer to defeat a human being in chess. Operators could even “debug" it by ear, using a radio to listen to its interference patterns like a secret code.

By 1957, MANIAC was succeeded by MANIAC II, and the original MANIAC became a teaching tool at the University of New Mexico.
Photo 1: The MANIAC with two operators, 1952.
Photo 2: Paul Stein (sitting) and Nicholas Metropolis play chess against the MANIAC, 1956.
Photo 3: Programmer and Operator Lois Cook at the MANIAC, 1952."

10/26/2026

The MAARC Facebook post for Monday, 26 October provides the answers to yesterday's Famous Names quiz. It tests your knowledge of the names of famous persons in vintage electronics science and engineering history. Most of us are familiar with the last names of famous people, but how many firsts names can you match with the last names. Here is the first batch:

1 - Armstrong - American electrical engineer who developed FM radio

2 - Babbage - English mathematician who developed the first mechanical programmable computer

3 - Backus - American computer scientist who developed the FORTRAN language

4 - d' Arsonval - French physicist and inventor of the moving-coil galvanometer

5 - Einstein - Austrian/American physicist who developed the theory of relativity

6 - Hopper - American Navy admiral who coined the term computer "bug"

7 - Schottky - German physicist who invented the screen-grid vacuum tube and discovered the Schottky effect

8 - Tesla - Serbian electrical engineer who dabbled in high voltages and wireless communications

9 - Van de Graaff - American high voltage experimenter

10 - von Siemens - German scientist credited for founding electrical engineering in Germany, unit of conductance named after him

And the choices were:

A - Albert
B - Charles
C - Edwin
D - Ernst
E - Grace
F - Jacques
G - John
H - Nikola
I - Robert
J - Walter

And here are the answers:

1 - C - Edwin Armstrong - American electrical engineer who developed FM radio

2 - B - Charles Babbage - English mathematician who developed the first mechanical programmable computer

3 - G - John Backus - American computer scientist who developed the FORTRAN language

4 - F - Jacques d' Arsonval - French physicist and inventor of the moving-coil galvanometer

5 - A - Albert Einstein - Austrian/American physicist who developed the theory of relativity

6 - E - Grace Hopper - American Navy admiral who coined the term computer "bug"

7 - J - Walter Schottky - German physicist who invented the screen-grid vacuum tube and discovered the Schottky effect

8 - H - Nikola Tesla - Serbian electrical engineer who dabbled in high voltages and wireless communications

9 - I - Robert Van de Graaff - American high voltage experimenter

10 - D - Ernst von Siemens - German scientist credited for founding electrical engineering in Germany, unit of conductance named after him

Did you get Honorable Mention?

RadioFallFest 2026 Vintage Electronics Expo October 18 @ 8:00 am - 4:00 pm EDT Davidsonville Family Recreation Center 3789 QUEEN ANNE BRIDGE RD., DAVIDSONVILLE, MD, United States Our second biggest event of the year. Flea Market Gates Open at 8:00 a.m. Walk-around Auction at 11 a.m. Main Auction at....

10/25/2026

The MAARC Facebook quiz for Sunday, 25 October, is a little different. It tests your knowledge of the names of famous persons in vintage electronics science and engineering history. The list I found was too long to post all in one week, so we're spreading things out over a few weeks. Most of us are familiar with the last names of famous people, but how many firsts names can you match with the last names. Here is the first batch:

1 - Armstrong - American electrical engineer who developed FM radio

2 - Babbage - English mathematician who developed the first mechanical programmable computer

3 - Backus - American computer scientist who developed the FORTRAN language

4 - d' Arsonval - French physicist and inventor of the moving-coil galvanometer

5 - Einstein - Austrian/American physicist who developed the theory of relativity

6 - Hopper - American Navy admiral who coined the term computer "bug"

7 - Schottky - German physicist who invented the screen-grid vacuum tube and discovered the Schottky effect

8 - Tesla - Serbian electrical engineer who dabbled in high voltages and wireless communications

9 - Van de Graaff - American high voltage experimenter

10 - von Siemens - German scientist credited for founding electrical engineering in Germany, unit of conductance named after him

And the choices are:

A - Albert
B - Charles
C - Edwin
D - Ernst
E - Grace
F - Jacques
G - John
H - Nikola
I - Robert
J - Walter

Honorable Mention will be posted for the top scorers.

RadioFallFest 2026 Vintage Electronics Expo October 18 @ 8:00 am - 4:00 pm EDT Davidsonville Family Recreation Center 3789 QUEEN ANNE BRIDGE RD., DAVIDSONVILLE, MD, United States Our second biggest event of the year. Flea Market Gates Open at 8:00 a.m. Walk-around Auction at 11 a.m. Main Auction at....

10/24/2026

The Saturday, 24 October MAARC Facebook post takes us back into the earliest days of vintage electronics. It comes to us curtesy the "At The Controls" page and author Sean Brady.

"Twenty-five year old Douglas M. Perham (left) of Palo Alto worked with fellow technician C. Albertus and engineer Peter V. Jensen to build this 1910 Poulsen arc transmitter and receiver, the first built in Palo Alto, California, by Poulsen Wireless (later Federal Telegraph). Perham also worked with Jensen on experiments that led to the development of Jensen's Magnavox loudspeaker. This photograph is featured on page 40 of Jane Morgan's book "Electronics in the West" with this caption: "(L to R) Douglas Perham, C. Albertus, Peter Jensen with 5 kw Federal-Poulsen arc station equipment, about 1910. Arc is mounted on box at left. Note tuning k***s and multiple-unit microphone above telegraph key on operator's table."

Some of the comments from this post were also worth repeating. Our own radio history expert Robert Lozier commented "In those primitive years the arc oscillator produced CW. Audio modulation was achieved by placing the parallel multiple element carbon microphone in series with the antenna circuit. Straight CW could be heard maybe 3 to 5 times further than with audio modulation." This led to Jaan Kolk commenting "Federal Telegraph used the Poulsen arc very successfully for wireless telegraphy, achieving a dominant position in the market. Because the arc could not be quenched and restarted rapidly, on-off keying was not an option. Poulsen's system switched a reactive element in and out of the tuned circuit for keying - a system known as frequency-shift keying. (Poulsen himself considered that an undesirable expedient for which a better solution was needed, but Federal made good use of it.) Experimental amplitude-modulated systems were not very successful."

Birger Dorvil added these fine comments: "Oh, this posting hits my soft point, and I simply cannot resist to comment it. Peter L. Jensen, who was employed as an apprentice and later as an assistant to the inventor of the arc transmitter, Valdemar Poulsen in Copenhagen, was actually also one of the first persons in world to perform a voice modulated transmission by a CW transmitter. Several attempts had been made, but one evening in May 1907 Peter and two of his friends went to the test facilities in Lyngby, as Peter had got the afterthought, that if you connect the microphone in series with the ground connection, it might work. He made the necessary setup, connected the microphone and started the arc transmitter. One of his two friends was asked to start counting, and Peter and the other friend started listening in a shed 100 meters away by using a simple crystal detector connected to a ticker, and - nothing happened. Enormous disappointment! By pure incident Peter put his hand on the ticker thus stopping it, and suddenly he could hear his friend counting: "8-9-10. Can you hear me?"

The story above is as I remember it from reading Peter's autobiography published in 1948. In 1909 Peter and mechanic Carl Albertus, who is also seen in the photo, left Denmark heading for California to supervise the construction of two complete Poulsen radio stations ordered by Cobrun and Elwell.

The other only man in the world, who had managed to broadcast speech and music on CW, was Reginald Fessenden in 1906, using an alternator. But this was an extremely expensive piece of equipment, transmitting on a very low frequency, 50 kHz, which could not be altered instantly, thus making it impractical to use in comparison with the Poulsen arc, where the frequency could be altered e.g. by changing a capacitor.

Frequency Shift Keying was not used on all arc transmitters. Smaller transmitters were often keyed by absorption keying or back-shunt keying. This also applies to the only still working alternator, the Alexanderson Alternator at the radio station SAQ Grimeton in Sweden, designed by the Swedish engineer Ernst Alexanderson, employed at General Electric. https://alexander.n.se/en/"

Ever own a pair of Jensen speakers? Now you know a bit more about the man behind the name.

10/23/2026

The Friday, 23 October MAARC Facebook post continues our series in how a vintage radio works. Today, the topic is on the antennas used in radio receivers.

There are about as many types of antennas as there are types of radios, and in my estimation, antennas are sort of a black art. Many early radios used long wire antennas, as this example that came out of the December 1985 "MAARC Newsletter" (see photo).

Ed Lyon, back in June 1989, posted an article in that month's edition of the "MAARC Newsletter" entitled "RADIO COMPONENTS - ANTENNAS." It was number 38 in his series entitled "Radio Historical Notes." Here, along with some photos I found, are some excerpts from that article:

"After 1920, broadcasting began. The broadcast frequencies were higher than those used in long-haul communications, and so the antennas were smaller. For receiving, especially, antennas were the objects of considerable popular press attention. It seemed that everybody who was anybody in radio had a pet receiving antenna which out-performed all others. Since the broadcast transmitters all sent via vertically-polarized antennas, most efficient reception was on similar antennas, but the directivity of long-wire inverted-L antennas often made the difference between hearing the desired station and getting nothing but static.

These long-wire aerials were the "standard" in broadcast receiving from 1921 to about 1924, when the superheterodyne receiver first became popular. This receiver could be made very sensitive, and so the antenna used could be relatively inefficient, especially if it was equally inefficient at picking up static. Furthermore, the early superhets radiated some portion of the local oscillator signal generated within each receiver. If the antenna was large and efficient, so was the unwanted radiation of this signal, resulting in interference to other listeners.

Quite early, in the last decade of the 1800s, the directive property of the loop antenna was discovered, and the employment of loop antennas, even at very low frequencies, became commonplace on some ships. For the superhet, loop antennas were very useful. They offered sufficient signal-collecting capability to permit broadcast listening while radiating relatively little undesirable local oscillator signal. Experimenters' superhets had the loop antenna mounted right on top of the set (see photo), while the run-of-the-mill set for John Q. Public had the loop built into the door, lid, or cover of the cabinet. Elegant parlor radios such as the Radiola Super VIII (see photos) and the Music Master-Ware 250 and 460 models had the loop well-concealed in the cabinet. These fine sets provided controls for rotating the loop structure toward the intended broadcaster to achieve the best reception.

Radio amateurs (hams), given parts of the frequency spectrum thought to be worthless for other purposes, usually were free to use frequencies higher than other allocations. Thus, they were the first to put the superhet to the real test of sensitivity, receiving signals from very small transmitters located half a world away. Their antennas, which could have been fairly small had they been simply scaled from the antennas used by the Navy and the long-haul commercial communicators, were instead made quite large, to give them more efficiency and "gain." At frequencies used by hams, which ranged up to about 30 MHz by the end of the 1920s, balanced (Hertzian) dipoles (see photo) rather than vertical Marconi antennas worked better, and some very creative work was done on arrays of dipoles. These antennas were the forerunners of the television antennas we see every day--the Yagis (see photo), log-periodics (see photo), and the "bow ties" (see photo). Hams invariably erected them as high in the air as possible, to get better gain, especially at low wave-launch angles, promising greater distances in communications.

Meanwhile, in the broadcast band, where the primary thrust in receivers was "socket-power," the advancement of portable sets operable from batteries took a back seat. As long as users had to plug in the set to a power socket, they might as well connect a long-wire aerial, too. This trend was furthered when short-wave bands were added to broadcast receivers, answering the public clamor for "all-wave" reception. For such a wide range of wavelengths, only a broad-band aerial, like a long-wire, would work well enough, considering also the cost-cutting in the minds of radio designers.

Even little table-models (midgets) had hanks of wire drooping out of their backsides as antennas. Then, the loop was remembered, and it soon found its way into virtually every set, at least for the broadcast band. In large consoles, like some Zeniths, RCAs, and Philcos, these loop assemblies were rotatable, to take advantage of their directivities (see photo), but in most table-models with fixed loops the whole set had to be moved around to optimize the reception of any given station. Some radio makers used helical ("slinky"-like) loops, but over ninety percent of the loops in use by 1940 were spiderweb-wound on fiberboard spokes. Its flat profile worked well with the cabinet shape, acting as a back panel (see photo). Shortwave bands in these radios usually required external antennas since the loops were tuned to respond only in the broadcast band, hence external antenna terminals were provided. Most consumers simply draped a wire around the baseboard behind the radio for such reception.

World War II saw the proliferation of ferrites as size-reducing devices in radio circuit coils or inductors. Ferrites are ceramic-like substances made from iron oxides or iron powder. Being magnetic like iron, but without the eddy-current losses of solid iron, ferrites enabled makers to reduce the physical sizes of coils in wartime radios by factors of ten or more, just as mica, waxed-paper, and ceramics had permitted the size reduction of condensers, relative to air-dielectric types. Postwar radio designers saw ferrite-cores in loop antennas as a way of reducing the sizes of loops as well. The first such antennas, called "loopsticks," were about a half-inch in diameter and about eight inches long (see photo). Finally, then, radios could be made as small as tube cooling would allow, and this meant that while socket-powered radios wouldn't be able to shrink much, owing to the tube heat generated, battery-portables could be made to fit the pocket, with battery size setting the miniaturization limit.

Of course, we all realize that the low power drain of the transistor made even the battery size negligible. Today, a broadcast receiver can be made the size of a packet of matches-- battery, loop antenna, and all. And for all-wave operation, a small whip antenna will suffice."

That just about sums it up. All you ever wanted to know about radio receiver antennas. Thanks Ed.

10/22/2026

A brief article for the Thursday, 22 October MAARC Facebook post. This one comes from the "Vacuum Tubes / Valves" page, curtesy author Tiziano Iten. It is entitled ".........The Tube Racket..1956........."

"This photograph depicts Joseph Bernard Lynch of Boston, arrested in 1956 for fraudulent "tube rebranding". Lynch bought defective radio vacuum tubes for pennies and rebranded them to appear new and under warranty. His scheme was exposed in the July 1956 issue of Radio News magazine (Page 40/41). Following his conviction, he received a two-year sentence for the crime."

Just for fun, I brought up my eBay app and typed in 'vacuum tubes.' I only got 120,000 hits. Sorted by 'Highest Price plus Shipping' there were 5 posts all with the same photo. These were for the following:

10,075 12AU7 tubes, asking $80,250 (~$8.00 a tube)
7,900 12AT7 tubes, asking $59,250 (~$7.50 a tube)
8,800 6AU6 tubes, asking $47,999 (~$5.50 a tube)
3,334 6AQ5 tubes, asking $34,400 (~$10.30 a tube)
4,260 6AL5 tubes, asking $25,560 (~$6.00 a tube)

No mention of these tubes being tested. No indication if they are new or used.

In my opinion, the tube racket is still alive and well. 😂😂😂

10/21/2026

The MAARC Facebook post for Wednesday, 21 October, brings us some photos from last Sunday's RadioFallFest Vintage Electronics Expo, but first we must acknowledge our Archaic Scientific Words and Definitions Quiz winner. Honorable Mention goes out to John D. Foell with a perfect score.

We had great weather for RadioFallFest. The parking lot was filled with vendors by 8:00 AM. With over 60 persons in attendance (about a third more than our monthly usual) sales and auction activity was brisk. The highlight of the event was the sale of a pair of good testing, original, Western Electric 300B vacuum tubes that were donated to the National Capital Radio and TV (NCRTV) Museum that sold for $1,200. Those proceeds all go to our NCRTV partner to assist in their expenses. The local Scouting America troop provided delicious food and drinks for sale at good prices.

MAARC holds monthly meetings in Davidsonville, MD (in January through March, May, and July through November) and Centreville, VA (in December and April). These events always feature tailgate flea market sales, auctions, and for most months a presentation. Visit our website (https://maarc.org/) for event updates.

Our next big Vintage Electronics Expo (we call RadioActivity) will be held June 3 through 5, 2027, at the Crowne Plaza Hotel in Annapolis, MD. That event will include free outdoor and paid indoor vending, multiple presentations, an Old Equipment Contest, a banquet, and two big auctions. Our theme for RadioActivity 2027 is kit and home brew vintage electronics. MAARC your calendar for that event. You won't want to miss it.

10/20/2026

A brief post for the Tuesday, October 20th MAARC Facebook post. It comes to us from the "Ham Radio Operators" page and author Chester Johnson, but it all about early frequency modulated (FM) broadcast radio.

"The $250,000 Gamble That Gave Us FM Radio: The Day Static Died Forever!

On July 24, 1939, communications history was made on a hilltop in central Massachusetts when station W1XOJ went on the air. It was the world's first full time, high-power pioneer FM (frequency modulation, encoding audio by varying a radio wave's frequency rather than its amplitude) broadcast station.

The Static-Free Revolution

​Throughout the 1920s and 1930s, AM (amplitude modulation) radio ruled the airwaves. But AM had a massive flaw: static. Thunderstorms, power lines, and household appliances caused crackles and pops that ruined sound quality. Legendary inventor Major Edwin Howard Armstrong solved this by inventing FM radio, which produced crystal clear, high fidelity audio virtually immune to atmospheric noise. However, major radio networks heavily invested in AM infrastructure were hesitant to embrace the new technology.

​Enter John Shepard III, founder of New England’s Yankee Network. Shepard believed FM was the future and spent over $250,000, a massive fortune during the Great Depression, to build W1XOJ atop Mt. Asnebumskit in Paxton, Massachusetts. ​When W1XOJ began broadcasting 16 hours a day on 43.0 MHz, Shepard and his engineers had to solve two wild challenges:

* ​The First Wireless Studio Link: To get high-fidelity audio from his Boston studio to the transmitter 43 miles away without quality loss from copper phone lines, Shepard installed a 250 watt VHF radio beam on 133 MHz. This was one of the earliest working Studio Transmitter Links (STL) in history.

* ​A Broadcaster Without an Audience: When the station signed on, there were only about 25 FM receivers in the entire world, all hand built to Armstrong's custom specifications! Shepard bet on FM long before receiver manufacturers even mass produced sets for the public.

​Shepard’s gamble proved that static-free, high fidelity radio was viable, paving the way for modern FM broadcasting."

The part of this post regarding there being only 25 FM receivers got me to doing a little digging. I came across an article on the Bright.net website about the earliest FM radio receivers. Here is what it had to say: "The first FM radios (other than experimental ones made in Armstrongs lab) were made by General Electric. The very first was a series of 25 radios commissioned by Mr. Armstrong for field tests and had a frequency range of 41-44 mhz. These GE radios cost $400 each and were built very early on in 1938. The order went in late 1937.

I am not sure if they were assigned a "model number" but the example shows Cat. 5100997. These radios were not very aesthetically pleasing and looked more like they really belonged in a laboratory setting. Obviously, they used an external speaker of I'm sure very high quality. Images courtesy of Mike Katzdorn (see photos).

Then it occurred to me. I have seen that radio before, right at our big Vintage Electronic Expo we call RadioActivity in June 2017, where it took first prize and best in show at our old equipment contest. Attached are the photos of Mike Katzdorn's FM receiver from that show, a blow up of his accompanying write-up, and Mike.

10/19/2026

The Monday, 19 October MAARC Facebook post provides the answers to yesterday's Archaic Scientific Words and Definitions Quiz from the RF Cafe. This particular quiz tests your knowledge of archaic scientific words & definitions. Choose the best answer for the spirit of the quiz; i.e., the one that represents the newer term or the abandoned definition. Here are the quiz questions:

1. Gutta percha
a) 16th century Indian physicist
b) Latin for "cat gut," used for stringed instruments
c) Cable insulation
d) Explosive compound

2. Condenser
a) Capacitor
b) Air pump
c) Mass compactor
d) Electrical probe

3. Luminiferous aether
a) Flame created by laboratory heaters
b) Medium that supports the transmission of light particles
c) The "light of the moon"
d) Glowing gas

4. Thermionic valve
a) Vacuum tube
b) Heat flow switch
c) Systolic pump
d) Lock

5. Dephlogisticated air
a) Dry (dehumidified) air
b) Perfect vacuum
c) Supersaturated air
d) Molecular oxygen

6. Corpuscle
a) Low-ranking enlisted man's bicep
b) Free radical
c) Electron
d) Light particle

7. Audion
a) Music aficionado
b) Sound generator
c) Vacuum tube triode
d) Sound level meter

8. Caloric
a) A stomach settling medical remedy
b) Unit of work
c) Unit of electrical resistance
d) Fluid responsible for heat flow

9. Leyden jar
a) Glass vacuum chamber
b) Energy storage device (capacitor)
c) Calibrated nudge
d) Test tube

10. Voltaic pile
a) Battery
b) Hemorrhoid
c) Large heap
d) Nuclear reactor

And here are the answers:

1. Gutta percha
c) Cable insulation

Gutta percha is a natural form of rubber that was the first successful insulation for undersea communications cables in the 19th century. Pictured is cable manufacturing with gutta-percha at the Telegraph Construction and Maintenance Company in Greenwich, London, circa 1865.

2. Condenser
a) Capacitor

Condensers were so-called due to their ability to collect and "condense" charges into a given volume.

3. Luminiferous aether
b) Medium that supports the transmission of light particles

As early as the days of Newton, it was believed that a special medium existed that accommodated the movement of light particles (prior to their wave nature being discovered). That medium was dubbed luminiferous aether.

4. Thermionic valve
a) Vacuum tube

A thermionic valve is what the Brits call a vacuum tube. Thermionic comes from the boiling off of electrons from the cathode, and valve, of course, derives from the devices' ability to switch current on or off. The first thermionic valve was Fleming's diode, but the term valve is used to address all vacuum tube types.

5. Dephlogisticated air
d) Molecular oxygen

To deflogisticate means to render burnable. Oxygen supports combustion, hence the name. The phlogiston theory, a superseded scientific theory, postulated the existence of a fire-like element dubbed phlogiston contained within combustible bodies and released during combustion or rusting. The name comes from the Ancient Greek φλογιστόν phlogistón (burning up), from φλόξ phlóx (flame). The idea of a phlogistic substance was first proposed in 1669 by Johann Joachim Becher (pictured).

6. Corpuscle
d) Light particle

So-named by Isaac Newton.

7. Audion
c) Vacuum tube triode

Lee De Forest called his newly discovered amplifying device an Audion (not sure why).

8. Caloric
d) Fluid responsible for heat flow

It used to be thought that caloric was a fluid that transferred heat from bodies of higher temperatures to bodies of lower temperatures. Cannon boring experiments conducted in 1798 by Colonel Sir Benjamin Thompson, aka Count Rumford, debunked the belief. Pictured is Joule's apparatus for measuring the mechanical equivalent of heat.

9. Leyden jar
b) Energy storage device (capacitor)

Benjamin Franklin used a Leyden jar as part of his kite flying experiment to prove that lightning was a form of electricity (no he didn't "discover" electricity).

10. Voltaic pile
a) Battery

All four answers are proper definitions of a pile, but the one that fits the spirit of this quiz is, of course, a battery. Alessandro Volta, inventor of the first practical wet-cell battery, so-named it because it looked like a pile - a 5th definition for the word "pile" that means a long rod-like beam used to support structures.

Did you get Honorable Mention?