Pi pad is
A. One of the possible configurations used in an RF circuit
B. One of the possible configurations used in an audio circuit C. One of the possible configurations used in Attenuators
Answer C… one of the possible configurations used in Attenuators. The Π pad (pi pad) is a specific type of attenuator circuit in electronics whereby the topology of the circuit is formed in the shape of the Greek letter “Π”.
Shortwave listeners use to send letters or postcards to the stations they picked up and this is how the station would know how far the signal was being picked up; Station WOR was associated with what department store A. Macy’s New York B. Lord and Taylor New York C. Bambergers New Jersey D. Hahne and Company Answer C… Bambergers, Newark New Jersey. WOR radio was established by Bamberger Broadcasting Service in 1922. The return QSL from Bambergers was a pamphlet with a description and drawings of the radio station and the departments on each floor. The broadcast studio was located on the sixth floor of its downtown headquarters. It was the first radio station
WOR radio was established by Bamberger Broadcasting Service in 1922. The broadcast studio was located on the sixth floor of its downtown headquarters. It was the first radio station on the East Coast to broadcast opera and a morning gym class in the 1920s. Its FM station, W2XOR (then W71NY, now WEPN-FM) began broadcasting in 1940 or 1941. On October 11, 1949, WOR-TV (channel 9) signed on the air, becoming the last of the New York metropolitan area VHF television stations to begin operations; in the same year, Bamberger was re-incorporated to General Teleradio, in part due to General Tire and Rubber’s increased investment in the station. Transmission was from the WOR TV Tower in North Bergen, New Jersey, until 1953, and from the Empire State Building thereafter. In 1952, General Tire acquired General Teleradio from Macy’s, merging it with the Don Lee Network to form General Tire’s broadcasting division.
Information on Bamberger’s broadcasting is from Wikipedia and the QSL brochure below is from DX History
QSL Cards : The earliest reference seems to be a card sent in 1916 from 8VX in Buffalo, New York to 3TQ in Philadelphia, Pennsylvania. Now the standardized card with callsign, frequency, date, etc. may have been developed in A. 1917 B. 1919 C. 1921 D. 1923 Answer B… The standardized card with call sign, frequency, date, etc. may have been developed in 1919 by C.D. Hoffman, 8UX, in Akron, Ohio. In Europe, W.E.F. “Bill” Corsham, 2UV, first used a QSL when operating from Harlesden, England in 1922.
In an RST it has all the same reports as an RS report plus a suffix, what is the suffix A. Speed B. Tone C. Time D. Location Answer is B… Suffixes were historically added to indicate other signal properties, and might be sent as 599K to indicate a clear, strong signal but with bothersome key clicks
LED or Light Emitting Diode also known as Electroluminescence was discovered by A. H. J. Round B. Carl Accardo C. Madame Marie Curie D. Georges Destriau Answer is A… H.J. Round a British Experimenter of the Marconi Labs in 1907 using a crystal of silicon carbide and a cat’s-whisker detector.
The most common RF mixer is known as A. Jones Cell B. Gilbert Cell C. Barrie Cell D. Howard Cell Answer is B… The basic circuit concept that is employed in the Gilbert cell mixer was originally devices by H E Jones, but it was used in other applications.
The Gilbert cell mixer topology was first used as a mixer by Barrie Gilbert around 1967 / 68. Although Gilbert himself did not suggest the use of the name, it is widely used to describe this mixer circuit topology.
The S stands for “Strength”. Strength is an assessment of how powerful the received signal is at the receiving location. Although an accurate signal strength meter can determine a quantitative value for signal strength, in practice this portion of the RST code is a qualitative assessment, often made based on the S meter of the radio receiver at the location of signal reception. “Strength” is measured on a scale of 1 to 9.
The R stands for “Readability”. Readability is a qualitative assessment of how easy or difficult it is to correctly copy the information being sent during the transmission. In a Morse code telegraphy transmission, readability refers to how easy or difficult it is to distinguish each of the characters in the text of the message being sent; in a voice transmission, readability refers to how easy or difficult it is for each spoken word to be understood correctly. Readability is measured on a scale of 1 to 5.
The first really successful duplex was designed by Joseph Barker Stearns of Boston in 1872. This was further developed into the quadruplex telegraph by Thomas Edison. The device is estimated to have saved Western Union $500,000 per year in construction of new telegraph lines.
He was president of Franklin Telegraph Co., from 1869 to 1871, during which time he invented the first practical system of duplex telegraphy which was successfully applied to the English, French and Belgian lines. Two years later this system was used for the Atlantic cables. He sold rights under his duplex patents to the Western Union Telegraph and Cable Companies, receiving large royalties for the use of his inventions from governments in England, France, Italy, Spain, Belgium, Russia and India, and several submarine cable companies. From 1879 to 1880, he was employed as engineer by the Mexican Telegraph Company in making, laying, and putting into operation the cables of that company between Galveston, Texas, and Veracruz, Mexico. In 1881, he performed a similar service for the Central and South American Telegraph Company, whose cables extended from the Isthmus of Tehuantepec in Mexico to Callao, Peru, in all between 4,000 and 5,000 miles. This work he completed in 1882.
The T stands for “Tone” and is measured on a scale of 1 to 9. Tone only pertains to Morse code and other digital transmission modes and is therefore omitted during voice operations. With modern technology, imperfections in the quality of transmitters’ digital modulation severe enough to be detected by human ears are rare.
Extremely rough hissing note
Sixty cycle a.c or less, very rough and broad
Very rough a.c. note, no trace of musicality
Very rough a.c., very harsh and broad
Rough, low-pitched a.c. note, slightly musical
Rough a.c. tone, rectified but not filtered
Rather rough a.c. note, moderately musical
Rough note, some trace of filtering
Musically modulated note
Filtered rectified a.c. but strongly ripple-modulated