Friday, August 31, 2012

The Sprayberry Academy of Radio

If you mail it in now, today, get ready for your place in Radio Television! Not really, but inexplicably there still are radio schools in America.The Sprayberry Academy of Radio was a correspondence school from the height of the golden era. It existed for about 15 years operating from at least half a dozen different locations then vanished overnight. The first address I've found was from 1943: 610-K University Place NW, Washington (9) D.C. That first booklet he's selling is called "HOW TO MAKE MONEY IN RADIO."

In 1944 Frank L. Sprayberry began appearing in ads in magazines like Radio Craft, Mechanix Illustrated, Popular Science, Radio Electronics, Radio News, and others. The ads were often full page, with color. The mailing address for the Sprayberry Academy of Radio in these early ads was always in Pueblo Colorado but it did change a bit. Somtimes it was Room 5568, Room 2055, or Room 1088, one time it's listed as dept 55-L but always in the Sprayberry Building or just "1118 Sprayberry Building." I suspect the varied room numbers are bogus and only meant to identify specific advertisements as generating the business revenue. The ads began mentioning television as early as 1948. But the Pueblo location always lacks a street address. I've had no luck locating the mysterious Sprayberry Building. I believe that it was actually a PO Box. The earliest ad I found was in 1944 and it lists the address as Box 500RF. More here.

But early on they also used an address in Chicago: 20 N. Wacker Drive Chicago. That is the address of a 45-story skyscraper known as the Civic Opera Building built in 1929. Many of the lesson books from the school bear this address. Around 1956 they began using a different Chicago address: Dept 10-J, 111 N. Canal Street, Chicago 6 Ill. The block is now mixed use with both condos, offices and retailers sharing space.  In 1957, just a year later there's a new address again: 1512 Jarvis Avenue, Chicago 26, Ill. that lot now belongs to a Public Storage company. More here.

In 1958 the ads got smaller but were still going with the Jarvis Avenue address. But the real change was in management. The company president abruptly changed from Frank L. Sprayberry to Mason R. Warner. Warner was the owner of the Mason Warner Company, located at 221 N. LaSalle St.in Chicago. It was an advertising company. You dont have to think too hard on how he might have gotten involved with Sprayberry. Prior to that Sprayberry had appeared as a floating head sporting the new title "Educational Director," but there was no mention of Mr. Warner. It's hard to date when the change  occurred. Sprayberry Academy appearances in advertisements and catalogs cease before 1960. It is in that year I find a short death notice in an issue of radio Electronics. They dedicated one whole sentence to a man who'd been buying full page ads for over a decade. "Frank Sprayberry, founder of the Sprayberry Academy of Radio & TV and widely known in the electronic industry, died at his home in Delray Fla."

Thursday, August 30, 2012

Art Nudnick's Musical Menagerie

The image on it's own is almost inexplicable. First I found the image on a Tumblr page. It actually originates with Andy Lanset who helps look after the WNYC archives in New York. It's online origin at Flickr makes the following claim:
"Rolf, the mandolin-playing terrier, was regularly featured on Art Nudnick's Musical Menagerie. The Sunday afternoon variety programme was a hit on WYNC in 1925"
This is the kind of story that you hope to be true. But so far I've found nothing. No Art Nudnick, and no Musical Menagerie... at least not on WNYC-AM.  But the date is plausible. It is one of the oldest licensed radio stations in the U.S.  It made its first official broadcast on July 8th 1924. they were operating on 570 AM at the time. They had the frequency all to themselves until 1928 when they were forced into a time share with WMCA-AM which lasted until 1931 when they became a daytimer on 810.

The mic is a prop but the mandolin looks curiously playable. It was the right era for strange radio programming, in those eccentric and experimental early years when there was a lot of airtime and not enough talent and programming to go around. I can't be sure.

Wednesday, August 29, 2012

Fulton Lewis Jr.

A 1987 editorial in the Washington Post newspaper referred to Fulton Lewis Jr. as "...one of the most unprincipled journalists ever to practice the trade." He died in 1966 so there was no rebuttal from Lewis. The accusation got me interested. Of course it was even more interesting that he was a radio journalist...

Lewis had political connections from birth. He was born in Washington D.C.in 1903, to affluent parents. He attended the University of Virginia and dropped out, then tried George Washington University School of Law and dropped out again. William F. Buckley he was not. But Lewis found his calling. He got a job as a reporter for the Washington Herald in 1924 and within three years he was an editor. He had his own political column, "The Washington Sideshow" which was syndicated and helped him grow his Rolodex beyond his family connections.  Already he was developing a style lacking objectivity. He was becoming a commentator, instead of a reporter. Lewis left the Herald to join Universal News Service, under the mighty and politically conservative Hearst family.

One source claims he broadcast a hunting and fishing news segment on WCAP-AM in 1925 but lets call that an apocryphal outlier. Lewis began filling news slots at 1230 WOL-AM then in 1936 he was offered a full-time position. [WOL has also occupied 1210, 1230 and presently 1450 AM) He was syndicated on the Mutual Broadcasting System shortly thereafter. His program ran from 7:00 PM to 7:15 PM Monday through Friday. He was an investigative journalist but not one that followed the news. He manufactured news to suit his opinions. Hearst had no problem with that and neither did the American Broadcasting Company. it turned out to be good for ratings. At his commercial peak, Lewis was heard on more than 500 radio stations and boasted a weekly audience of sixteen million listeners. He wasn't all politics. He enjoyed his fame enough to get a star on the Hollywood Walk of Fame. More here.

The book Political Commentators in the United States in the 20th Century by Dan D. Nimmo is more even handed but accurately describes him as a harbinger of our contemporary style of political commentary. Certainly Lewis was a partisan conservative commentator. He supported limited government, keeping the U.S. out of WWII, opposed both FDR and Harry Truman. He was accused of being an anti-semite as well. unsurprisingly he was sued for libel a few times. He was rabidly anti-communist, loathed unions, opposed farm co-ops, and supported Senator Joe McCarthy even after he imploded in a haze of liquor and hypocrisy which actually did hurt his ratings. He followed that up in 1955 by attacking the the U.S. funding of allied broadcasting project, Radio Free Europe.

Inexplicably he felt that this anti-communist propaganda outlet was being used to spread communism. When pressed, he parsed the semantics of being anti-Russia and not adequately anti-communist. It makes no sense now. Maybe you had to be there. RFE affiliated officials wrote him polite letters asking him to cool it. He politely wrote back but kept pouring it on. Sometime after his 40th individual attack broadcast there was a congressional inquiry and a little CIA involvement. The fight fizzled but he had already jumped the shark. he made a stab at TV and that didn't work out. He lost at least 200 radio stations from his network over the next couple years. Mike Wallace interviewed him in 1958 and you can see the video on the CSPAN site here.

But his core audience never left him. When Life magazine wrote an article criticizing him in 1950 they received hundreds of letters defending Lewis, and even a few cancellations for daring to criticizing him. After his death in 1966 Mutual Broadcasting asked his son, Fulton Lewis III  to take over the nightly program which he did until it was cancelled in1979. Today Lewis III continues the family tradition of being a deeply political radio man with deep government connections. More here.

Tuesday, August 28, 2012

A Moment of Silence Please

Today the Society of Broadcast Engineers (SBE) mourns the loss of its founder, John H. Battison.  The organization, which he headed for 48 years lives on.

In 1961, while Battison was the editor of Broadcast Engineering magazine, he wrote an editorial suggesting that it was time to form a business organization to represent the interests of broadcast engineers. Battison was already a member of the Institute of Radio Engineers (founded 1912) but it wasn't broad enough. At the time the Institute of Radio Engineers was toying with the idea of merging with the IEEE, which it did in 1963. Battison saw this as diluting the differing interests of different types of engineers. After two years of chatter no one picked up the baton so he ran with it.

Three months after the IEEE ate the IRE he ran an application form for the IBE in Broadcast Engineering, and mailed out 5,000 invitation letter. Their first official meeting was called to order at the 1964 NAB convention in Chicago. At the first meeting they changed the name from the Institute of Broadcast Engineers (IBE) to the Society of Broadcast Engineers; lest it get confused with the (IBEW) International Brotherhood of Electrical Workers. The SBE prospered and membership grew. Today it has over 5,700 members in the U.S. and 111 chapters in 25 other nations. Battison’s maneuver was ultimately great for his career and for the industry. He's been awarded repeatedly by the SBE, the NAB and even nominated twice as a FCC Commissioner. All the while he has continued to work as a radio engineer both in the field and in print. I am a member. If you actually read my blog... you probably are too.

Monday, August 27, 2012

The Father of Amateur Radio


James Brown is to Funk  as Hiram Percy Maxim is to Ham Radio. Hiram P. Maxim is a descendant of Hiram S. Maxim, the inventor of the Maxim machine gun. Tinkering was the family trade. So not surprising that the young Mr. Maxim was a mechanical engineering student. He graduated from Massachusetts Institute of Technology in 1886. Like dad he worked on firearms and patented a silencer in 1908. But he also worked on cars... and of course radio. More here.

H.P. Maxim had the amateur call signs SNY, 1WH, 1ZM, 1AW, and W1AW. That last one lives on as the ARRL Headquarters club station call sign. One of his transmitters, a rotary spark-gap model named "Old Betsy" is enshrined there as well. ...And with good cause, he founded the ARRL in 1914. He described Ol' Betsy in an article in Radiogram magazine in 1915.
"The receiving station outfit consists of a large loose coupler by means of which I can get very accurate tuning, an Audion Detector and variable condenser. The two sets of phones are usually connected in. The Transmitting sets consists of a 1 K. W. specially made transformer, glass plate condenser, oscillation transformer, ¼ H. P. General Electric Company motor running specially built quenched rotary spark-gap."

Hiram founded the ARRL in 1914 because he saw an organized  network was needed  to relay radio messages. He had developed an interest in Amateur radio due to his son Hiram Hamilton's own interest. [why are they all named Hiram?] H.P. didn't even start to learn Morse code until he was at least 40. Hiram got together with the Radio Club of Hartford and began recruiting hams. It sounds like a nice quiet job organizing hobbyists but it wasn't. In those years there was no FCC not even an FRC. For good or ill there was no regulating body of any kind. So there was work to be done. By September of 1914, there were 237 relay stations on board. But then WWI began in and the Navy tightened controlled radio broadcasting. More here.

H.P. organized a massive system test in 1916.  He had a test message was sent to the Governors of every State, and President Wilson in Washington, D.C. The message was delivered to 34 States and the President within 60 minutes. A year later there were more than 1,000 ARRL relay stations and similar tests reduced that to 45 minutes. By 1921 it was less than seven. In 1918 he led a delegation to Washington to try to get ARRL member relay stations moved to 425 meters to facilitate long distance relays. At the time everyone was sharing 200 meters. He got the wartime ban lifted.

It is interesting to note that the so-called father of ham radio has several patents on cars, gun parts but none on radio gear. He had a couple patents for ammeter dials and battery indicators, the rest are all silencers and motor vehicle related, or both. He died in February, 1936.

Friday, August 24, 2012

Epilogue, Issue no. 3


I was thinking about how rare radio 'zines are today. [more here] They didn't used to be, but there are only a scant few remaining today. The only one I am aware of are Electric Radio still run by  Ray Osterwald, the radio 'zine Paper Radio by DJ Frederick, and perhaps Nostalgia Digest... albeit in a somewhat broader context. Sure, there are hobbyist magazines, and technical trade magazines but what we're lacking are print publications for radio listeners. It's become a niche, and even the back issues are becoming rare and uncollected. Many will be lost forever. So with that in mind I intend to scan and share more of my collection to preserve what might otherwise be lost. This issue is particularly interesting because it notes the 'Final Mutterings' section the debut of the NPR network.
"An item of interest was reported a few days ago by a national news service: 'A live, non-commercial radio network will begin operation May 3 with the hook up of 90 stations across the country." The article goes on to explain this network is financed by the Corporation for Public Broadcasting... and though it will start primarily with news, it will eventually develop a 'full day of cultural attractions, including [sic] dramas, symphony orchestras and operas'."

Below is Issue #3 of "Epilogue" printed  January 15th 1971. (or maybe not. All the text ahead of it refers to April of that year... but also that it's running late.) The introduction names the editor as George Jennings and also that the prior issue only had a circulation of 150 copies. There were only 4 issues of this short-lived publication according to the bibliography of the essay Return With Us Now: Rise of the Old Time Radio Hobby by Ryan Ellet here.  It's full reach is uncertain but in a 1980 newsletter "Hello Again" by Jay Hickerson both Jennings and Epilogue were still being mentioned together. More here. The paper Epilogue is printed on is what I'd today call construction paper. It's very heavy but aging poorly and brittle. Despite the discoloration and the crumbling the scan is completely readable and all the content is intact. Enjoy.

Download all 59MB

Thursday, August 23, 2012

DIGITAL MODES: Part 3 (PSK)

PSK (Phase Shift Keying) is totally different from ASK and FSK and has numerous varied implementations. While Amplitude and frequency are easily understood Phase isn't for a layperson so let's start there. It's mostly easily understood in a diagram. So I nicked a 3 phase AC waveform from Wikipedia. Look at the red line first. that's a sinusoidal wave, looks like a bell curve. The other two waves are out of phase with it.  So knowing that in the US all AC power is 60 Hz, you can immediately understand how multiple phases of waves can occupy the same frequency.
In applications of PSK each phase is assigned a unique pattern of binary digits. Usually, each phase carrys an equal amount of data which we measure in bits. Usually each phase carries an an equal number of bits. There are two primary ways of mapping bits to symbols to data. One requires the receiver to be able to compare the phase of the received signal to a reference signal. That's what we call CPSK (Coherent Phase Shift Keying.) The other is Differential Phase Shift Keying (DPSK.) In DPSK the demodulation can be performed without a reference signal, it only refers to changes phases of signal. Since there is no reference signal, and no need to compare to a reference signal this is simpler to implement than CPSK but it is less robust and more prone to error.

The first type might seem familiar already. BPSK aka Binary Phase Shift Keying, it's also called 2-PSK, and PRK (Phase reversal Keying) and even 2-QAM in some circles though that's not exactly accurate.  BPSK uses two phases separated by 180° .  It's very robust, and requires the most interference and noise to disrupt it. The downside is that each phase is only able to modulate at 1 bit per symbol. So it's data rate is inadequate for many applications.  Also, despite the natural robustness, if there is an external phase shift in the communications channel, the demodulator is unable to discern one phase form another. The solution for this is to encode them differentially i.e. DPSK (Differential Phase Shift Keying.)

There are two primary types of DPSK. We have CDPSK (Conventional  Differential Phase Shift Keying) and SDPSK (Symmetrical Differential Phase Shift Keying.) CDPSK for all intents and purposes is just DPSK. It doesnt use a reference signal which is why sometimes a thesis writer feels the need to refer to it as Non-Coherent Differential Phase Shift Keying. personally I find it confusing. DPSK is a form of phase modulation that conveys data by altering the phase of the carrier wave. Like BPSK there are still just two phases, they're just each differentially encoded. This gives it greater redundancy as data is being transmitted on the current bit or symbol but also the previous one. SDPSK indicates a zero bit with a negative 90° phase shift and a one bit with a positive 90° phase shift and circular polarization. It transmits at 4,800 baud which is pretty good. This is mostly used for satellite communications. More here and here.

Quadrature phase-shift keying (QPSK) is another common type of PSK.  It uses 4 different values of phase to transmit symbols and has several variants. If you Google it please note that it's also called quaternary PSK, quadriphase PSK, 4-PSK, or even 4-QAM. With those four phases, QPSK can encode two bits per symbol. This is double the data rate of BPSK. A variant of that is Staggered Quadrature Phase Shift Keying (SQPSK) also called OQPSK (Offset Quadrature Phase Shift Keying.) In OQPSK the in-phase and quadrature components of a signal are offset from each other by 1 bit. The problem with these is that the amplitude can spike and that's a problem at the receiving end. 4QPSK still has two bits per symbol, but it limits the degree of phase change to reduce the dynamical range of those amplitude fluctuations. More here.

Now we get into the really big acronyms. Shaped Offset Quadrature Phase Shift Keying (SOQPSK) further reduced the large amplitude fluctuations. It shapes the in-phase and quadrature components of a signal like 4QPSK,but the signal transitions are smoother and the amplitude remains constant. It is similar to Feher-patented Quadrature Phase Shift Keying (FQPSK). The primary difference being that FQPSK is patented by Feher and heavily used by the military. FQPSK has a whole family of iterations and sub-types FQPSK-S, FQPSK-B... etc. Also from Feher comes Cross Correlated Phase Shift Keying (XPSK.)  In XPSK a known amount of cross correlation is introduced between the in-phase and quadrature channels. There is even a modification I read about that maintains a constant envelope appropriately titled CEFQPSK - Constant Envelope Feher Patented Quadrature Phase Shift Keying. More here. These variations on QPSK all shape the I and Q waveforms such that they change very smoothly, and the amplitude of the signal stays constant.

Dual-polarization quadrature phase shift keying (DPQPSK) or dual-polarization QPSK involves the polarization multiplexing of two different QPSK signals, doubling the spectral efficiency. It uses 16-PSK instead of QPSK which I can't even visualize. Presently national ISPs are experimenting with RZ-DPQPSK to speed up their networks even further. Clearly PSK is where you'll find all the current RF research jobs.

VOCABULARY TERMS
  • PSK- Phase Shift Keying
  • DPSK  - Differential Phase Shift Keying
  • CDPSK - Conventional  Differential Phase Shift Keying
  • SDPSK - Symmetrical Differential Phase Shift Keying
  • CPSK - Coherent Phase Shift Keying
  • BPSK -  Binary Phase Shift Keying
  • DBSK -  Differential Binary Phase Shift Keying
  • QPSK - Quadrature Phase Shift Keying
  • XPSK - Cross Correlated Phase Shift Keying
  • OQPSK - Offset Quadrature Phase Shift Keying
  • SOQPSK- Shaped Offset Quadrature Phase Shift Keying
  • SQPSK - Staggered Quadrature Phase Shift Keying
  • 4QPSK -  π Quadrature Phase Shift Keying
  • DQPSK - Differential Quadrature Phase Shift Keying
  • DPQPSK - Dual Polarization Quadrature Phase Shift Keying
  • SDQPSK - Symmetric Differential Quadrature Phase Shift Keying
  • FQPSK - Feher Patented Quadrature Phase Shift Keying
  • CEFQPSK - Constant Envelope Feher Patented Quadrature Phase Shift Keying
  • RZ-DPQPSK - Return to Zero Dual Polarization Quadrature Phase Shift Keying

Wednesday, August 22, 2012

DIGITAL MODES: Part 2 (FSK)


Let me stop and explain "symbols" for a moment. In ASK a symbol might just be a dot or dash in Morse code. Other digital modes use multiple audio tones for each symbol being transmitted. This is usually explained in documentation by appending a number to the mode acronym. MFSK16 for example uses 16 tones for each symbol.   Not that's the only implementation of MFSK, there is also MFSK8 and so on. 

So if ASK is Amplitude Shift Keying you probably already guessed that FSK is Frequency Shift Keying. In FSK, the center frequency of the carrier wave alternates between multiple values. A common application of this would be BFSK (Binary Frequency Shift Keying.) In BFSK only two frequencies are used. In this scheme, the 0 and the 1 are called the space frequency and the mark frequency respectively. More here.

AFSK (Audio Frequency Shift Keying) is another early FSK-type digital mode. In this scheme the data is represented by changes in the frequency of an audio tone. AFSK differs from regular frequency-shift keying in performing the modulation at baseband frequencies. In radio applications, the AFSK-modulated signal normally is being used to modulate an RF carrier (using a conventional technique, such as AM or FM) for transmission.AFSK differs from BFSK in that AFSK is modulating baseband frequencies, BFSK is modulating a carrier wave. It can send and receive data up to1,200 baud.  It is also used in the the Emergency Alert System and by NOAA

The problem with MFSK is that the acronym stands for two different types of MFSK, Minimum Frequency Shift Keying and Multiple Frequency Shift Keying. Multiple Frequency Shift Keying is just FSK using more than two frequencies. The most common application of it is Dual-Tone Multi-Frequency (DTMF) also known as touch tone dialing. The other MFSK, (Minimum Frequency Shift Keying) is also known asMSK is (Minimum Shift Keying) yet another application of FSK. MSK is a more efficient form of FSK. MSK encodes each bit as a half sinusoid and thus the waveforms used to represent a 0 and a 1 bit differ by exactly half a carrier period. More here.

GMSK (Gaussian Minimum Shift Keying) is based on MSK.Thsi is a form of continuous-phase frequency-shift keying modulation. the data stream is first shaped with a Gaussian Filter.  A Gaussian filter modifies an input signal by convolution with a Gaussian function (named after Carl Friedrich Gauss) these apply an exponential function to a general quadratic function, in this application the result looks like a bellcurve because it reduces sideband power. More here.   If you think that's complicated try wrapping your head around PDGMSK (Pulse Driven Gaussian Minimum Shift Keying) More here.  This modification to GMSK sort of hurts my brain.

Even more complex is CPFSK, Continuous Phase Frequency Shift Keying.  In this application of FSK the carrier phase abruptly resets to zero at the start of every "symbol." In normal FSK at the end of each "symbol" the phase of the carrier wave changes because it's signals are generated by separate oscillators that aren't phase-synchronized. CPFSK changes its frequency continuously but the phase is a constant. It maintains a constant amplitude signal and has very narrow bandwidth requirements. DCPFSK stands for Differential Continuous Phase Frequency Shift Keying and please don't ask me to explain it. I stopped reading when I encountered the word "phase trellis." More here and here. I'll get into more phase related shifting in part 3.


VOCABULARY TERMS
  • FSK - Frequency Shift Keying
  • BFSK- Binary Frequency Shift Keying
  • DTMF - Dual-Tone Multi-Frequency
  • AFSK - Audio Frequency Shift Keying
  • MSK - Minimum Shift Keying
  • MFSK - Multiple Frequency Shift Keying
  • PDGMSK - Pulse Driven Gaussian Minimum Shift Keying
  • DCPFSK -  Differential Continuous Phase Frequency Shift Keying
  • GMSK - Gaussian Minimum Shift Keying
  • CPFSK- Continuous-phase frequency-shift keying

Tuesday, August 21, 2012

Transcription Mystery Disc #137

This is a Wilcox-gay Recordio. It's 6.5 inches in diameter and has a metal core. This side of the disc is labeled, but it's all scratched out as you can see. It says "Wonderful You" and the artist seems to be Heinie. It is dated clearly to 1/8/47.
Heinie


The song is solo piano, barely over 2 minutes long. I assumed it was a take on "You Wonderful You" from the Judy Garland Movie Summer Stock but that came out in 1950. It may be an original. The pianist Heinie remains a mystery as well.

Monday, August 20, 2012

Goddamn Tesla Museum

The site of the former Tesla lab at Wardenclyffe is up for sale. Groups have been trying to save it for years and The Oatmeal is trying to raise money to  make that happen. Tesla continues to be under-appreciated in historical terms. Please head on over to The Oatmeal and consider donating to the good cause of radio history and the future dominance of geek culture. I did.






Friday, August 17, 2012

DIGITAL MODES: Part 1 (ASK)

If you have no interest in the technical mumbo-jumbo you can skip today's post.  This is about the wild world of digital modulation schemas, (aka digital modes) specifically shift keying. These are ways to convey and/or transmit data by modifying or modulating the carrier wave. There may be math.  Any serious digital modulation scheme uses multiple distinct signals to represent digital data, each mapping patterns of binary digits. If you can't handle that you should probably stop right here.

The term "Digital" as used in digital modes just means that it uses discrete values. Information, like text or other data can be converted into numeric data, usually binary. Binary is just another way to say "zeroes and ones."  The use of binary harks back to early analog computational machines. These used switches to do their math. A simple switch is either open or closed, this corresponds to 0 (closed) and 1 (open). So in transforming analog data into binary we are only ever seeking three things, compression , redundancy and security. Redundancy and security usually requires more data, and compression seeks to squish that in to an ever smaller space so these are somewhat at odds. That conflict has generated oodles of differing formats as we improve upon and replace older outmoded formats.
 
Lets start with OOK. On-off keying (OOK) the simplest form of shift keying.  In its most simple implementation zero and one are represented by the presence or absence the carrier wave for a defined duration. aka make/break. This is most commonly used to transmit Morse code. It sounds rudimentary and antiquated but it's also used in optical formats. the upshot is that it requires little bandwidth, the downside is that it's susceptible to noise and lacks redundancy. More here.

Technically OOK is a type of ASK (Amplitude Shift Keying.) Amplitude-shift keying represents binary data as any set of variations in the amplitude of a carrier wave. So technically no carrier wave counts even though that's sort of cheating. All ASK schemas are susceptible to noise because they're basically AM radio. One of the more common forms is BASK (Binary Amplitude Shift Keying.) It does have redundancy, unlike OOK. In BASK the signal is divided into four pulses of equal duration which represent the bits in the digital data. The number of bits used for each character is usually eight, seven of which represent the 128 possible characters, the last bit is used to check for errors.

More interesting is QAM (Quadrature Amplitude Modulation) It's both an analog and a digital modulation schema. It uses two carrier waves, that are out of phase with each other by 90°.  But both of these waves are amplitude modulated using the ASK digital modulation or amplitude modulation as the above. These carrier waves can be individually frequency modulated and/or phase modulated which is where we head in part 2.

VOCABULARY TERMS:
  • OOK -On-off keying
  • ASK - Amplitude Shift Keying 
  • QAM -  Quadrature Amplitude Modulation
  • BASK -  Binary Amplitude Shift Keying

Thursday, August 16, 2012

Radios Most Unrehearsed Show!


The Breakfast Club radio show in Chicago, on 1540 WLS-AM and its announcer Don McNeill. the program aired from 1933 to 1968. McNeill hosted the program for it's entire run, over 35 years. It ran for an hour on the NBC Blue Network weekdays at 8:00 AM. With the exception of his support for public prayer, he was a strictly apolitical character... something that's missing in our modern discourse. He debuted it in 1944 ostensibly to support the troops; a sentiment that was much more congruous in WWII. But even the day after the attack on Pearl Harbor he avoided the war topic and just let the new bulletins do the talking. If you get curious for more details, John Doolittle's book about the program, Don McNeill and His Breakfast Club is not to be skipped.

His radio career didn't' start in Chicago, not even in Illinois. It began 90 miles to the north in Milwaukee back in 1928. He graduated from Marquette University  in Milwaukee, class  valedictorian and started as an announcer at WISN-AM. and later for WTMJ-AM owned by The Milwaukee Journal. In 1930 he moved to Louisville and began announcing on  WHAS-AM. He tried to shop a vaudeville skit to radio stations on the west coast but that tanked. More here.

So in 1933, he auditions for an unsponsored morning program called The Pepper Pot. McNeill took over the show in June and renamed it The Breakfast Club. Pepper Pot is a terrible name for a radio shoe. It sounds like a restaurant. His re-formatted program was meant to be humorous and and topical but mostly just very wholesome and family oriented. It'd be pretty boring by modern standards. They had musical guests and both comedians and celebrities.After a few months letters started coming in with cornball jokes and bad amateur poetry. he incorporated it and the show became virtually an ad lib hour. It was called "radios most unrehearsed show" When the show was cancelled in 68' Don McNeill stepped out of the limelight forever. He wouldn't give interviews, he was just done. He died on May 7, 1996.

Wednesday, August 15, 2012

Manufacture of Modern Radio Valves


Courtesy of the Phillips Museum there are several silent films online about the manufacture of early vaccum tubes.   Sadly Embedding was disabled so I'll just give you the links.

Tuesday, August 14, 2012

Transcription Mystery Disc #136

This is a 6.5-inch Silvertone transcription disc with three clearly defined tracks that spins at 78 rpm with an outer edge start. It has a metal core and common brand label but no identifying markings. The first track is of some country-sounding  accordion ballad. But the bed noise is too high to discern anything, it's comparable to the song on the A side which has similar bed noise issues.

Unknown 1959 recording
 
The 2nd and third tracks were similar to each other, but totally unlike the first cut. These had enough laughter that at first I thought it had a live studio audience. Then I realized what it was. I had done it again. I had found a recording of drunk people at a party.

Most of the dialog is unintelligible, there are a couple jokes about shortness, and bashful girls but toward the end someone jokes about a train and clearly says the year "1959."  I'm going to presume that is near the recording date.

Monday, August 13, 2012

Duddell's singing voice

The first AM transmitters were arc transmitters aka arc converters. The first model to generate a continuous wave (CW) were invented separately by Elihu Thomson and William Du Bois Duddell. These models generate a carrier wave by continuously shocking a tuned circuit. This was the best we had until vacuum tube technology appeared on the scene.

Previous to these models transmitters were all spark gap transmitters. These just emitted a series of short arcs hence the term. These sparks were noisy and emitted broadband noise. Real improvements to these transmitters just timed the sparks so instead of emitted a series of damped waves, they edged closer to transmitting a continuous wave. This is what Marconi was using from about 1895 forward. He was still using them in 1901 for his public transatlantic experiments even when there was superior technology available.

Elihu Thomson had beat the hell out of that spark gap idea by 1892 (patent 500630). He discovered that a carbon arc with a tuned circuit would "sing" i.e. emit audio frequencies as well as radio frequencies. This is only a year after Tesla's invention HF coupled oscillatory circuit (patent 454622) in 1891. Tesla's was for arc lights, but it's actually closely related. Thomson's work also extended into arc lighting. This is the transmitter Reginald Fessenden used in his experiments.

It's worth noting that one of the reasons that it is believed that Fessenden may have broadcast voice and even music is that this arc converter couldn't be stopped and started (make/break) fast enough for practical Morse code. (This is widely debated) But it had other more serious problems. The intensity was variable as was the frequency. Fessenden made numerous improvements of his own mostly between 1900 and 1903. after that he moved onto rotating spark-gap transmitters that were generally inferior concepts.

But before Fessenden and after Thompson is where we squeeze in William D. Duddell. e was a a British physicist and electrical engineer. Like Thompson and Tesla he was working on arc lighting. In 1897 he invented an Oscillograph sensitive enough to see the shape of a wave with a frequency of up to 100 Hz. Tools matter. It was the first time we could see AC waveforms. In 1899 he discovered that arc lamps could emit frequencies of up to 1 MHz. His own oscilloscope couldn't quantify that, nor could any until after 1920. Around 1900 he invented an arc transmitter based around a carbon arc (like Thompson) but with a shunt to a resonant tuned circuit. This cancelled out the resistance of the RLC circuit. RLC stands for  Resistor, Inductor, and a Capacitor. [Engineers use the character "L" for inductance, in honor of the physicist Heinrich Lenz. But also because we are poor typists. ]  More here.

Duddell's Singing Arc Transmitter was only able to emit waves at about up to 15,000 Hz. Most of it's output was still audible sound. He had doubts that it could emit RF at all. He played "God Save The Queen" at a demonstration in 1901. This was the device that Valdemar Poulsen began improving up on in 1903 (patent 789449), and commercially feasible in 1908. The Poulsen arc transmitted continued to be used until about 1920. More here.

Friday, August 10, 2012

Valdemar: Great Dane

Valdemar Poulsen is chronically under-rated by history. He was Danish, which is probably part of the problem. Popular radio history is very anglo-centric. We Americans carve out exceptions for Marconi, Hertz and Tesla, but little more. So this leaves Valdemar Poulsen on an island so to speak. But he was indisputably brilliant and far ahead of his time. In 1902 (30 years before Edwin H. Armstrong) Poulsen invented FM. In September of 1902 he patented an RF arc oscillator that used FM. He wasn't the first, that was Cornelius Ehret, but that's beside the point. Ahead is ahead whether it's 30 years or 30 minutes.

Here's the difference: while Ehret imagined an FM system and patented an FM system, he failed to make a working prototype. Poulsen succeeded where Ehret failed. He imagined and patented a working model. If that's not impressive enough, he also invented magnetic recording. So... why don't you know who this guy is? More here.

He was a poor student, and was particularly bad with mathematics. He family pushed him into medical school and he didn't do so well there either. He found work at the Copenhagen Telephone Company where he had time to experiment. He may or may not have read Oberlin Smiths Electrical World article on theoretical Magnetic recording. But his world was along those lines. Oberlin thought wire recording was impractical and was thinking more aline the line of a threat embedded with ferrous particles. Smith turned out to be right in the long run. But Poulsen managed to get it to work with wire, a battery, a magnet and some telephone parts. On 1st December 1898, he filed a patent in Denmark for the Telegraphone, the first magnetic recording device in history. In a variation of the wire method he also patented a 4.5 inch diameter steel disk with an embossed magnetic recording and playback was achieved by spinning the disc... like a hard drive.

In 1908 he developed an arc converter that we now call the Poulsen Arc Transmitter.  It was capable of transmitting at frequencies up to 100 kHz. This was widely used in early experimental radio before the rise of the vacuum tube. It was a huge improve ment on Duddell's Singing Arc Transmitter which only could achieve 10kHz. By 1920 some Poulsen Arc transmitters were operating as high as 1000kW!

He died on 23 July 1942. He was 73 years old. Germany had fully occupied Denmark by 1940, but they allowed the Danish government to function until 1943. So Poulsen never saw Denmark liberated, but he never saw it dominated either.

Thursday, August 09, 2012

Gernsback For Beginners

He was a scientist that loved science fiction, perhaps the first true geek to rise from in the annals of science. The Annual Science Fiction Achievement Award formally became the "Hugo" in 1993, it was informally known by that name as early as the 1950s. It was Hugo Gernsback whose pulp sci-fi magazines elevated the genre.While a scant few identifiable fantasy works of fiction existed before 1800, scifi could not exist on any large scale before the consumers understanding of science was more common. When Hugo Gernsback  founded Amazing Stories magazine in 1926 things took off. It was the first fiction magazine to be focused exclusively on science fiction. More here.

Gernsback supported the careers of many now classic scifi writers. But I write about him here because he was a classic radio man. He also published the magazines Modern Electrics, Radio Amateur News, and Science and Invention. He founded the radio station WRNY (which will later get it's own post) he also was an early experimenter in television. He also founding the Electric Importing Company which was the world's first radio supply company—yes, before radio shack.

This booklet is one from a set of ten, of which I only have six or so. They are as follows:
1. How to make four Doerle short wave sets
2. How to make the most popular all-wave 1 and 2 tube receivers
3. Alternating current for beginners
4 . All about aerials
5. Beginners Radio Dictionary
6. How to Have Fun With Radio
7. How To Read Radio Diagrams
8. Radio For Beginners
9. Simple Electrical Experiments
10. Television
I have scanned all 32 pages below from No. 8 in the series and wrapped it into a nice tidy pdf. The technology is all out of date but interesting historically. I will try to get around to scanning the others.

Download all 72 MB

Wednesday, August 08, 2012

Edna's Kitchen on KCIM-AM

The curse of writing about the arcane is that some stories will be forever incomplete.This one starts at  a class-B AM station in small-town Carroll, Iowa.  It's about 100 miles North East of Omaha, NE. In other words nowhere. If you're in Carroll Iowa, don't take that personally, nowhere is usually very pretty because there are no people in it.  KCIM-AM signed on in 1950 under a CP owned by Carroll Broadcasting. It was the fourth addition to a small stable of stations including KCIM, KKRL and KIKD.  That 1950 date is important because it's the only one I have.
"During my many years at Women's Director of Radio Station KCIM, in Carroll, Iowa, I have been besieged by listeners and friends to compile my recipes in book form. For many years, I have collected recipes as a hobby, many of them being favorites from home and friends in Cedar Falls, other places where I have lived, and you, my listeners. Every recipe contained in this little book has been tried in my own kitchen, and many are used over and over. The brown of the cover and the yellow of the pages are indicative of the color scheme in my very own kitchen; the copperware on the bricks is also from my own apartment. I am especially indebted to the management of KCIM for permitting me to make this recipe book available to you...

All of that comes from a single cook book pictured above. The cook book has no date in it. All I know is that it must have been printed after 1950 because of the station sign on. The cookbook has the typical numbered sections: Breads, Doughnuts, Pancakes; Meats, Casseroles, Salads; Cakes, Candies, Cookies, Deserts, Frostings; Pies; and Favorites. The blub refers to a radio program which may or may not have been named "Edna's Kitchen."  Edna's surname is not listed nor are the dates the program ran.

But in he broadcasting yearbook KCIM lists an Edna G. Collins as women's director, from at least 1958 through 1960, and that must be her.
Interestingly There was also an Edna Dahl, who was wife to a grocer in Des Moines, IA. Her name still graces the Dahl's website as "Ednas Kitchen."  It just happens to be a different Edna in a different kitchen.  More information is welcome if anyone happens to have any.

Tuesday, August 07, 2012

Transcription Mystery Disc #135


This is a capitol Pro-disc that dates to 2-15-47. It spins at 78 rpm and has an outer edge start. It's labeled "Mary  Johnny Long."  The recording sounds like it's off off a radio program. It might be a recording of a program guesting or hosted by Johnny Long of the Johnny Long Orchestra. They were featured on "Teen Time" and the Judy, Joe and Johnny program among others.

Johnny Long Orchestra?



The audio on this disc is poor. The damage is unusual. It appears to have been overheated so while the groove walls have not collapsed, there is visible damage to the surface. It may even have been two discs stuck together...it's quite bad. The audio even after being edited and filtered is abysmal. There's enough signal to identify that there is some banter, some harmony singing... nothing conclusive.

Monday, August 06, 2012

Zoe, Radio Dog

Even a dog can be famous for five minutes. Zoe got written up in at least three geek magazines. She was in both Popular Science and Mechanix Illustrated Magazine in 1939, and Radio Craft in 1940. Zoe was a trained German Shepard, called an Alsatian in the UK. I wouldn't have mentioned that except that Zoe was an Australian Alsatian, and American readers would be confused by the English convention. I was. So more here, here and here.
"ZOE, an Alsatian police dog attached to the Sydney (Australia) Police Force, is shown performing tricks in response to commands issued to her via short-wave radio. A miniature radio receiver was strapped to the animal’s back and a police officer whispered instructions into the microphone of a transmitter located some distance away. Hearing her master’s voice, Zoe dutifully carried out the commands."
The dog is not radio controlled in the technical sense. The dog was trained for 2 years by Constable Denholm with verbal commands like any other trained dog. It's just that in this case the commands are issued by a short wave radio strapped to the dog. Zoe probably recognizes Constable Denholm's voice, but verbal commands. In another demonstation Zoe climbed up and down ladders, turned a faucet on and off, took off her collar, and fired a revolver. For the record there was not a gun strapped to the dog.

For these demonstrations Denholm, strapped a miniature shortwave radio receiver and a battery pack on the back of Zoe. Then from a shack fifty yards away he issued commands into a microphone connected to a portable shortwave transmitter. The fame lasted perhaps two years, what happened to Zoe after that I have no idea.

Friday, August 03, 2012

Bottle of Magic

This video "Bottle of Magic" follows the development of the vacuum from John Fleming thru the Audion at the hands of Lee de Forest, and the work of Thomas Edison's staff. It stops with the work of Bell labs of course.


Thursday, August 02, 2012

Nitrocellulose, not Acetate!

Every Tuesday night I digitize another home recording disc from my collection. I have ripped over 100 and will probably break 150 before I exhaust my current sources. I refer to them collectively as "transcription discs" which confuses some people. I'll get into why in a second, first an important definition.
Tran·scribe (trn-skrb)
tr.v. tran·scribed, tran·scrib·ing, tran·scribes, tran·scrip·tion
1. Text. To make a full written or typewritten copy (dictated material, for example).
2. Computer Science. To transfer (information) from one recording and storing system to another.
3. Music.
a. To adapt or arrange (a composition) for a voice or instrument other than the original.
b. To translate (a composition) from one notational system to another.
c. To reduce (live or recorded music) to notation.
4. Audio. To record, usually on tape, for broadcast at a later date.
A transcription disc is also called an acetate disc, test acetate, dubplate , lacquer or instantaneous disc.  In collecting circles transcription is meant for commercially mass produced radio recordings intended for distribution. In their lingo a lacquer is probably the most accurate for the home recordings I digitize, though that's also often meant to refer to a high end master recording. The term instantaneous disc sort of covers the shoddy make and disposability of the discs but even some of the supposedly good quality discs can fall apart. I've come to believe that transcription should be adopted as the correct term for them all as a group. Just look at the dictionary definition!

The most common term is "acetate disc", and it is the most incorrect term of all. It dates to before 1934 when such discs were coated in what was sometimes inaccurately called "wax" but was usually ethyl cellulose or cellulose acetate. The coated disc is not exactly original. Edisons first cylinders in 1877 were tinfoil wrapped around a small metal cylinder. In 1885 Chichester Bell and Charles S. Tainter developed a cardboard cylinder coated in a compound of Beeswax and paraffin. [source]

None of these post-1934 discs contain a drop of acetate. Acetate is any derivative of acetic acid. it's most common form is cellulose acetate, which  is used as a film base in photography, cigarette filters and in adhesives. All makes and models of discs are coated in nitrocellulose, not acetate. Nitrocellulose lacquer is made by taking cotton and treating it with sulfuric and nitric acid, which makes an acidic pulp. This can be strained to produce a thin watery resin. It's treated with a strong base to eliminate the acid like potassium hydroxide or sodium bicarbonate. Then the remaining resin can be mixed with a solvent, like acetone and plasticized (at least early on) with Castor Oil producing the "lacquer" that coats transcription discs.

Nitrocellulose lacquer was first invented in 1921 by Edmund Flaherty using the above process. He worked for the DuPont Chemical Company. DuPont sold the rights to Ford. Ford had found that it could be mixed with pigments thus making a quick-drying paint. Ford was all about a faster cheaper assembly line. The leap from painting it on sheet metal car chassis to metal core discs wasn't huge. It is also used as a wood finish, in laquerware, and gun cotton.  His work was derived from that of Henri Braconnot who discovered in 1832 that nitric acid, when combined with starch or wood fibers, produced a combustible explosive material that he called "xyloïdine." In 1838 Théophile-Jules Pelouzediscovered it again experimenting with acid treated paper. He called it "nitramidine." A third chemist, Professor F. J. Otto discovered it again in 1846, and he was the first to publish the process. More memorable was it's discovery by Christian Friedrich Schönbein. He discovered the process after he accidentally detonated his cotton apron. You can't top that.If you want to read more abotu the very early developments of nitrocellulose you can dig up the 1911 book Nitrocellulose industry: a compendium of the history, chemistry Vol 1 &2 by Edward Chauncey Worden.

Wednesday, August 01, 2012

CABL to CPVR

Cable radio was invented before cable TV. The earliest claimant dates to at least December of 1922. [source] There were even more exotic experiments that preceded that by a few decades but it's over-charitable to call them radio. So the title goes to J. A. Gustafson the GM of the Fredonia Telephone Company in Kansas who wrote the below quote in an issue of Telephony Magazine:
“We have added a radio receiving set to our central office equipment and furnish radio service to our subscribers. This service is furnished over cable pairs that would otherwise be idle...To furnish this service we use a standard radio receiving set and three stages of amplification. A circuit is furnished to the subscriber at a monthly rental for the circuit only, and the subscriber buys his own loud-speaker or receivers."
Another very early cable radio experiment was in Dundee, Michigan. It was first offered as a luxury service at a whopping $1.50 per month. It was run by the Farmer's Telephone Company, who still exists. A similar system was built in Lorain, Ohio, but it only served about 700 homes. Cable radio took off overseas before it came to America.  Unlike a true radio, a cable radio doesn't need much in the way of components or even an antenna. Using amplifiers, and relays across twisted pair a "radio" would only need an on/off switch and a volume dial. since there was only one station there was no need even for a tuner. It was just a speaker with a variable resistor. So in a small urban foot print it can be cost effective for consumers. In south Korea they were building out large municipal systems as early as the 1940s. Similar systems popped up in Europe and the pacific.

In the U.S. the expansion was mostly with rural systems that operated like amplified speaker wire. Homes didn't need to have power in order to have radio. In the large rural southern regions that still hadn't been electrified that had commercial appeal.  One of the earliest urban systems in the U.S. was built by Muzak.  Muzak built it's own system in the 1940s in New York but took one in the chops when they carried a WOR-AM broadcast of the world series in 1941. The subsequent lawsuit was actually the start of retransmission fees. Patrick R. Parsons book Blue Skies: A History of Cable Television covers this ear in great detail. More here too.

In the U.S. the first cable radio stations started cropping up in the 1970s. Cable TV was increasingly popular and the notion of piping in some audio channels seemed like a natural progression. The first commercial cable radio station in the United States was probably CABL-FM 108. It was carried on the Theta Cablevision system, serving homes in the West Los Angeles area. They first went live on January 1st 1972. The station was run by Brad Sobel, a former pirate radio man. According to him in a Billboard article potential audience was between 4,700 and approximately 25,000 (based on information provided by Brad Sobel in an article in Billboard. He was also still involved with KIIS-AM at the same time. He was later an engineer at KIQQ-AM, KWTH-FM, KZPN-FM, KCRY-FM and a slew of others. Brad was an all around radio man.

Another early station was 95.9 CPVR in Palos Verdes, CA. Tom Hewitt built the station from scratch and two locals, Mark Speer and Brad Gardner started the non-profit youth organization that staffed it. CPVR began cable casting in March of 1972. It was carried on the Times-Mirror cable system. Numerous universities hosted cable radio stations. There is some difficulty identifying which is a true cable radio station and which is carrier current. Some used both systems at different times. Records are scant and these stations were dying off in droves by the 1980s. Even the somewhat successful WLHE in Woburn, MA signed off in 1987. (The station had been founded by Larry Haber.) There are some broadcasters still simulcasting on cable TV. But I know of none that are on cable exclusively. The closest is probably WHAV,  who is still carried on the PEG government channel in Andover, Haverhill and Methuen Massachusetts. They also broadcast under part 15 at 1640 AM in Haverhill. More here.