Radio engineering time travel - 1925

Radio engineering time travel (1925)

I invite you to look at the "pictures" related to radio technology. They come from various sources. The gallery has its sister version in Polish and Russian. Versions in other languages will be added successively. More detailed descriptions can be found in other language versions (articles are related and can be displayed by clicking on the icons with flags on the left, top of the TRIODA website). Of course, I will complement translations of signatures quite slowly. All descriptions are displayed using the present tense and not the past - this is not a mistake only deliberate action - a reference to the original descriptions from those years. In order not to delay the possibility of viewing the gallery, this site is made available as a "site under construction" - for which I apologize to all guests. At the beginning and end of each set of photographs there are links allowing to change the period - calendar year.

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Radio Station 5CG
"Call 5CG has been assigned to J. M. Patterson, 601 North F St., Hugo, Oklahoma. He is using the Hartley circuit in a 20-watt C. W. transmitter, with 550 volts and 200 millis. on the plate and an antenna current of 2.5 amps. For phone 15 watts are used as oscillator and 10 watts as modulator in Heising circuit. 5CG is qrv for traffic, and will promptly acknowledge report of signals."
(Radio for February, 1925)

 
Amplification without Distortion
"You can make your set so that it will reproduce clearly and distinctly without distortion. The real pleasure in radio comes when you can understand and enjoy what you hear - voices that are natural - music that is clear in tone. In order to hear clearly and distinctly you want to be sure that you are using amplifying transformers that amplify the sound without distorting it."
(Radio for February, 1925)


Logging A Concert From San Francisco
Radio in the Icefields of the Canadian Rockies
A Remarkable Account of Reception Under Difficult and Unusual Conditions
By Lewis R. Freeman
(Radio for March, 1925)


A `Broadcast' Receiver from a Bucking Pack Horst
Radio in the Icefields of the Canadian Rockies
A Remarkable Account of Reception Under Difficult and Unusual Conditions
By Lewis R. Freeman
(Radio for March, 1925)


 Aerial at CPRO, Ottawa, Canada, 187 Feet Above the Street
Radio Activities on the Canadian National Railways
An Illustrated Description of Their Nine Radiocast Stations and Receiving Equipment on Trains
By W. H. Swift, Jr. Radio Engineer, Canadian National Railways
"RADIO as a definite part of the service offered to the community by a transportation system, may, perhaps, seem rather a visionary project, yet, so far as the Canadian National Railways are concerned, it is not in the mere experimental stage, or offered as an amusing plaything, but is seriously and definitely in daily use as one of the factors considered necessary for the convenience of the travelling public. The Canadian National Railways' radio department is now as truly a part of the system as those concerned with operation, traffic, express, telegraph, lands and colonization. Furthermore, this is the first railway system in the world to adopt radio as part of the regular service of transportation..."
(Radio for March, 1925)

 
Operating Room at CNRO, 435 Meters
Radio Activities on the Canadian National Railways
An Illustrated Description of Their Nine Radiocast Stations and Receiving Equipment on Trains
By W. H. Swift, Jr. Radio Engineer, Canadian National Railways
"It was during the early summer of 1923 that radio on the Canadian National Railways really came into being, after a number of years of interesting experiments...."
(Radio for March, 1925)


Operating Room at CNRA, Moncton, N. B.
Radio Activities on the Canadian National Railways
An Illustrated Description of Their Nine Radiocast Stations and Receiving Equipment on Trains
By W. H. Swift, Jr. Radio Engineer, Canadian National Railways
(Radio for March, 1925)


Radio- Equipped Observation Car
Radio Activities on the Canadian National Railways
An Illustrated Description of Their Nine Radiocast Stations and Receiving Equipment on Trains
By W. H. Swift, Jr. Radio Engineer, Canadian National Railways
(Radio for March, 1925)

 
Australian 3 B.Q.
(Radio for March, 1925)

 
Fort Leavenworth Radio Station, showing antenna system and views of transmitting equipment.
"The Army Radio Station at Fort Leavenworth Interesting Details Concerning a 10 K.W. Master Oscillator Transmitter"
by Paul B. Findley
"Some three or four years ago the War Department undertook to provide a radio net which would be capable of maintaining communication between Washington and the headquarters of all the Corps Areas, nine in number, for emergency use. The Naval radio station at Arlington, near Washington, was incorporated in this plan by installing there a transmitter and antenna system controlled from the War Department independently of those controlled by the Navy Department. Use was also made of several Other Naval radio stations already installed along the seacoast, in order to reduce the investment necessary...."
(Radio for April, 1925)


The New Army Transmitter at Annapolis - General View of 20 K.W. Tube Transmitting Equipment.
(Radio for April, 1925)


The New Army Transmitter at Annapolis - Oscillator Tube and Cooling Unit
(Radio for April, 1925)


Radio and Education - Miss Myrtle Palmer, penmanship instructor, and her studio class before the microphone at KGO during a recent test radiocast into the Oakland Public Schools.
(Radio for April, 1925)


Electrical Transmission of Pictures - Transmitting Apparatus with Synchronizing Motor at Left and Amplifier of Photo-Electric Cell Current Output at Right
(Radio for May, 1925)


Electrical Transmission of Pictures - Receving Apparatus with Lamp House at Left and Photographic Film at Right, Light Valve and Focusing Lens Between with Synchronizing Motor in Background.
(Radio for May, 1925)


Tales of the Tube Wreckers - Section of Replacement -Testing Laboratory
(Radio for May, 1925)


Radio for May, 1925


The Concert Selector - A Non-Radiating Four-Tube Receiver Using One Stage of Regenerative Radio Frequency Amplification - rear view
(Radio for May, 1925)


Transmitter at 3BHY
"The transmitter at 3BHY is of standard design with special attention to details. The oscillating circuit is a loose coupled Hartley with shunt feed of high voltage. The scheme of modulation used in the Heising system. For speech amplification three stages of audio frequency are used. The first two stages are General Radio transformer coupled with 160 volts plate battery and 13 volts grid bias using 5 watt W. E. tubes, filaments supplied with 6 volt storage battery. The last stage is push pull using All American transformers, with 5 watt W. E. tubes, plates supplied with 300 volts AC (using one 216 kenotron and filter circuit in B battery eliminator of our own design - nothing unusual) grid bias battery of 24 volts, filaments supplied with another 6 volt battery. For mike we use a Thorola loud speaker, leads of speaker connected to input of first stage audio frequency, no battery used..."
(Radio for May, 1925)


The Batteryless Receiver - A Compact Combination of a Reflexed Two Tube Receiver with An "A" and "B" Current Supply Set.
Front View of Batteryless Receiver.
(Radio for June, 1925)


Radio Station 2ABT
"Envy cannot but fill the heart of the amateurs examining the picture of 2ABT as printed herewith. George C. C. Freisinger, the owner and operator, has installed this 500 watt C. W. equipment at 219 West 81 St., New York City. He has innumerable cards from every U. S. district as well as from England, France, Italy, Spain, Canada and Cuba. He employs a coupled Hartley circuit and is most likely to be found on 75 meters...."
(Radio for June, 1925)


Views in and Around the Malabar Radio Station.
"AMATEUR and radiocast listeners on the short waves below 100 meters may have heard a distant telegraph station signing the call PKX, and wondered as to its location and nature. Located practically at the equator, on the island of Java, at Malabar, about 300 miles from Batavia, the Dutch East Indian Capital, PKX represents an interesting commercial installation maintained for communication between the Far East and Holland, as well a  the United States..."
(Radio for July, 1925)


Radio equipment on the "ELOISE."
Radio's Part in the Greatest Ocean Yacht Race
A Description of the Transmitting and Receiving Equipment Aboard the Yachts in the Tahiti Run
By D. B. McGown
(Radio for September, 1925)


Installation aboard the "IDALIA"
(Radio for September, 1925)


Transmitter and Receiver for Use on Seaplane Making the Flight From San Francisco to Honolulu in September.
(Radio for September, 1925)


New 500 watt, 5-80 meter Installation at 6X21D-6ZW
(Radio for September, 1925)


Radio Station 8ASE, 8AXG
(Radio for September, 1925)


Radio Station 9EGU
(Radio for September, 1925)


Dr. Kolster, inventor of the modern radio compass, operating the instrument on the S.S. "Leviathan." Above, loop with its supports on the flying -deck of the "Leviathan "; below, close to ceiling, the capacity compensating device, next, hand -wheel for rotating loop, mechanical compensator for error, sight -wires, dial; to the right, the six -tube receiver.
(Radio for October, 1925)


Circuit Diagram of a Typical Radio Compass
(Radio for October, 1925)


Horizontal Antenna and Equipment Used by General Electric Company Engineers for Radiation of Horizontal Waves.
(Radio for October, 1925)


The Arc comes back - Typical Ship Installation Showing 34 Kw. Spark Transmitter and 2 Kw. Arc Transmitter.
(Radio for October, 1925)


Radio Station 6CLV
(Radio for October, 1925)


250 Watt Transmitter at 6EA
(Radio for October, 1925)


40 and 80 Meter Low-Loss Tuner with 2 Stages of Audio at 6EA
(Radio for October, 1925)


An Ideal Audio Frequency Amplifier - Upper Side of Sub -Panel
"Directions for Making a Three Stage Impedance Coupled Amplifier of Unusual Quality, Adaptable to any Radio Set"
By Ernest W. Pfaff
(Radio for November, 1925)


Circuit Diagram of 3 -Stage Impedance Coupled Amplifier
By Ernest W. Pfaff
(Radio for November, 1925)


A Corner in RADIO's Calibration Laboratory
(Radio for November, 1925)


An Improved Loop Receiver - View of Completed Set
By R. Lewis Rockett
(Radio for November, 1925)


Schoolboys earning holiday money making bakelite bases. In the winter months, they are replaced by women workers.
(Radio for December, 1925)


A battery of Three Butt - Welding Machines. These machines automatically weld together the nickel wires that support grid, plate, and filament, the copper -clad bits that pass through the glass, and the copper lead -wires to the base. Chas.' Eisler, the mechanical wizard who designed these, and countless other tube machines used by Western Electric, DeForest, etc., is in the middle of the picture. The three-piece welder to the right costs $6,000.00 and performs operations amounting to 1/10 of a cent per unit. Scores of equally intricate machines are used today in tube - making.
(Radio for December, 1925)


Cementing bakelite bases onto the finished bulbs. The bases are baked on in the rotary oven.
(Radio for December, 1925)


An Ultra - Selective Crystal Set
(Radio for December, 1925)


Radio For Train Signals - Antenna on Cab Roof
(Radio for December, 1925)


Motorized Short Wave Phone Transmission - Short Wave Portable Transmitter in Motor Truck.
(Radio for December, 1925)

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