Inaccuracies of broadcasting
Posted: Fri Nov 07, 2014 1:42 am
Defying Gravity wrote:""On a trip to New York with his mother, he contacted Dr. Lee DeForest, inventor of the radio-telephone and vacuum tube. Townsend was only 16 years old when he bought one of DeForest's vacuum tubes and brought it back home with him, but he was able to construct a broadcasting station with it, the first such transmitter in Ohio. Even though he used only 10 watts of energy to power the transmitter, he received a postcard that he had been heard in California. Every Saturday night at the local college, he broadcasted music by an amateur orchestra called the "Green Imps." Although Dennison University turned off the lights at 10 p.m. when the school's generator was shut down, Brown devised an alternative system that carried the broadcast until 11 p.m. At that time there were only two other broadcasting stations in the country, WJZ of New York and KDKA of Pittsburgh."
If Brown was born in 1905, he would have been 16 in March of 1921. The above information is not accurate.
10/27/20 KDKA - 1020 Pittsburgh, PA
05/--/1921 WABC - 770 New York, NY
09/15/1921 WBZ - 1030 Boston, MA
10/13/1921 WWJ - 950 Detroit, MI
11/09/1921 KYW - 1060 Philadelphia, PA
12/07/1921 KWG - 1230 Stockton, CA
12/08/1921 KNX - 1070 Los Angeles, CA
12/09/1921 KCBS - 740 San Francisco, CA
Not knowing when Brown purchased the tube, it is safe to assume that since there is a reference to Dennison college that it would have been in the fall of 1921. By the end of 1921, there were 8 commercial broadcast stations.
Whomever provided Paul with the above information stated - " Even though he used only 10 watts of energy to power the transmitter .." - is not a proper description and shows a lack of research. Watts is never referred to as energy but power especially when referring to a transmitter. Watts is the SI for electrical energy so to state "10 watts of energy" is incorrect since watts is already an expression electrical energy and should be referred as "10 watts" and the use of the words "energy" or "power" is actually redundant. Secondly, -" he received a postcard that he had been heard in California." - displays a total lack of understanding of radio propagation. Ionospheric propagation occurs at night and if conditions are good requires very little power to accomplish. Many CB operators back in the 70's referred to this as "skip".
The entire statement appears to be constructed from someone who has very little knowledge of radio transmission and lack of historical facts.
The first vacuum tube was the Fleming Valve which operated with the process of "thermionic emission" which is the heating of an element (cathode) to release electrons. The Fleming Valve is the first rectifier and enabled the detection of radio signals as well as the use as rectifiers to convert AC into DC current.
Lee De Forest is the inventor of the Audion or Triode Vacuum Tube. It is the Fleming Valve with the addition of a grid element inserted between the cathode and anode (plate). This provides control of the flow of electrons from the cathode to the plate and thus small signals applied to the grid could be amplified.
Lee De Forest is not the inventor of radiotelephony.
The inventor credited with the modulation of radio waves is Fessenden. He is also credited with heterodyning which enables the same antenna to be used for transmission and receiving thus eliminating interference of the transmitted signal to the received signal.
This is another example where the writer of "Defying Gravity" was given wrong information. If the source of the information could not be accurate in regard to historical facts, how can "facts" in regard to Brown be considered accurate.
Mikado