Posts Tagged ‘historic’
Vacuum Tubes – Electronics at Work: 1943 Educational Film
In the classic educational film titled “Electronics at Work,” produced by Westinghouse in 1943, viewers are introduced to the fascinating world of vacuum tubes. This film highlights the crucial role these devices played in both military and commercial sectors, including radio telecommunications, radar, and various industrial applications. The narrative suggests that vacuum tubes provided the United States with a significant advantage during World War II, particularly in enhancing communication and technology.
The Continuing Relevance of Vacuum Tubes
Despite advances in technology, vacuum tubes remain in use today for several applications, including:
– Transmitting radios
– Medical devices
– Audio amplification systems
– High-frequency applications
Understanding Vacuum Tubes
The film outlines the six basic functions of electronic tubes and illustrates how each type is employed in different industrial and military contexts.
[embedyt] https://www.youtube.com/watch?v=ZJ6rN7WEjbc[/embedyt]
Structure of a Vacuum Tube
A vacuum tube typically consists of two or more electrodes housed within a vacuum inside an airtight enclosure. Key features include:
– Electrode Types: Most vacuum tubes have glass envelopes, although some utilize ceramic or metal casings with insulating bases.
– Leads and Sockets: The electrodes connect to leads that pass through the envelope via an airtight seal. These leads often take the form of pins, allowing for easy replacement in a tube socket, as tubes were a common point of failure in electronic devices.
– Capacitive Design: Some tubes feature a top cap on the electrode to minimize interelectrode capacitance, enhancing high-frequency performance and maintaining safety by separating high voltages.
The Evolution of Vacuum Tubes
The earliest vacuum tubes emerged from incandescent light bulbs, which contained a heated filament sealed in an evacuated glass envelope. When heated, the filament releases electrons into the vacuum through a process known as thermionic emission.
– Electrode Functionality: A second electrode, known as the anode or plate, attracts these electrons if it holds a more positive voltage. This mechanism results in a flow of electrons from the filament (cathode) to the plate, creating an electric field due to the potential difference between them.
– Diode Function: A vacuum tube with two electrodes is termed a diode, which functions as a rectifier. Diodes allow current to flow in only one direction, converting alternating current (AC) into pulsating direct current (DC). This technology is widely used in DC power supplies and in demodulating amplitude-modulated (AM) radio signals.
Film Availability and Production Details
This film is available in the public domain under Creative Commons, and it can be accessed through the Library of Congress Prelinger Archives. The film has been edited and converted to HD quality for better viewing. Introductory and closing music is provided by Nero 10, with commercial use rights granted.
This film not only serves as an educational tool but also highlights the enduring legacy of vacuum tube technology in the realm of electronics, illustrating its significant contributions to both past and present technological advancements.
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Go Back In Time – Vintage Film
Turning back time to virtually witness a critical historic method of shortwave communication using the fundamental mode of continuous wave modulation. This is a film from 1944, teaching the basics of Morse code, for military comms.
What is the proper (and most efficient) technique for creating Morse code by hand, using a manual Morse code key? Ham radio operators find Morse code (and the ‘CW’ mode, or ‘Continuous Wave’ keying mode) very useful, even though Morse code is no longer required as part of the licensing process. Morse code is highly effective in weak-signal radio work. And, preppers love Morse code because it is the most efficient way to communicate when there is a major disaster that could wipe out the communications infrastructure.
[embedyt] https://www.youtube.com/watch?v=qmg1MlstxWM[/embedyt]
While this military film is antique, the vintage information is timeless, as the material is applicable to Morse code, even today.
Credits: National Archives and Records Administration
Department of Defense. Department of the Army. Office of the Chief Signal Officer. (09/18/1947 – 02/28/1964)
ARC Identifier 36813 / Local Identifier 111-TF-3697. PRINCIPLES AND BASIC TECHNIQUE FOR GOOD, RHYTHMIC SENDING 0F MORSE CODE BY OPERATING THE HAND KEY.
Made possible by a donation from Mary Neff.
1939 Film: Morse Code on HF in New Zealand (Historical)
Before modern radio broadcasting, the trails were being blazed both in public broadcast, but also critical links out of the local area. Here’s a side-look back in time…. in this 1939 Film: New Zealand Shortwave Communications; Morse code (CW)
The romance of the radiotelegraph service (in this video, the service in New Zealand) is a fascinating aspect of communication history. The use of shortwave, longwave, and medium frequency spectrum for communication, particularly through Morse code, played a significant role in connecting people across vast distances. This service utilized the high-frequency spectrum known as “shortwave” (from 3 MHz up to 30 MHz) as well as the longwave (30 kHz to 300 kHz) and medium frequency spectrum (300 kHz to 3 MHz).
This short film is from 1939, and captures the essence of communication at that time in history, to and from New Zealand using shortwaves and Morse code. It showcases the importance of the radiotelegraph service in enabling long-distance communication during that era. The transition from Morse code via spark-gap communications to continuous wave (CW) modulation marked a significant advancement in the technology and efficiency of radio communication.
It’s incredible to see how technology has evolved over the years, transforming the way we communicate and connect with each other globally. Films like these provide a glimpse into the past and remind us of the ingenuity and dedication of those who worked in the radiotelegraph service to ensure effective communication across the seas.
[embedyt] https://www.youtube.com/watch?v=H-KUat5WEkU[/embedyt]
This film is a 1939 Government film scanned to 2K from a 16mm combined B/W reduction print.
“BEST REGARDSES” AND “BEST REGARDS’S”
“Best regardses” and “Best regards’s”
That’s silly, of course. We who speak and write in the English language know that you should not pluralize a word that is already in its plural form. “Best regards” means, “I wish you the best of regards.” It is implied that there is more than one regard. Perhaps there are a few, perhaps many more. It then is clear that we wouldn’t normally pluralize “regards,” into, “regardses.”
It is also silly to say that the best of regards owns something. How can a regard let alone a group of regards own anything? So, why “73’s” when written?
The usage of “73” comes from early landline telegraph (typically railroad telegraphy landlines). Originally devised in the era of telegraphs, 73 and other numbers were used to speed up the transmission of common messages over landlines by mapping common messages to these specific numbers. And, numbers were quicker to send than the longer messages the numbers replaced.
QST, April 1935, on page 60, contains a short article on the origin of the amateur radio vernacular, 73. This article was a summation of another article that appeared in the “December Bulletin from the Navy Department Office of the Chief of Naval Operations,” published December of 1934.
Here’s a quotation from that Navy article:
“It appears from a research of telegraph histories that in 1859 the [land-line] telegraph people held a convention, and one of its features was a discussion as to the saving of ‘line time.’
A committee was appointed to devise a code to reduce standard expressions to symbols or figures. This committee worked out a figure code, from figure 1 to 92.
Most of these figure symbols became obsolescent, but a few remain to this date, such as 4, which means “Where shall I go ahead?’. Figure 9 means ‘wire,’ the wire chief being on the wire and that everyone should close their keys. Symbol 13 means ‘I don’t understand’; 22 is ‘love and a kiss’; 30 means ‘good night’ or ‘the end.’
The symbol most often used now is 73, which means ‘my compliments’ and 92 is for the word ‘deliver.’ The other figures in between the forgoing have fallen into almost complete disuse.”
We can see, then, that “73” mapped to “best regards” or “my compliments” and was intended as a general valediction for transmitted messages. That’s why it is silly to say, “73s,” as that maps to, “best regardses” – 73s adds the plural to a plural. (And, don’t make it possessive, as in using, “73’s” – a regard cannot own something).
For reference and some more interesting background on this, see http://www.signalharbor.com/73.html
An example of on-the-air conversation (or, QSO—“QSO” is the shorthand Q-code for, “two-way exchange of communications”) illustrates proper usage of 73. When saying your goodbye, you would tap out the Morse code as follows:
TNX FER FB QSO. C U AGN. 73 ES HPY NEW YR.
That is interpreted as, “Thanks for the fine-business chat. I hope to see you again for another chat. Best regards and happy new year.”
This, if you choose to throw around shorthand Morse code number codes when you are speaking, you wouldn’t say, “73s.” You would say, “73.”
My friend, David Edenfield, opined, “This idea is beyond turning into glue from the dead horse it’s beating again. This is so petty to be concerned with this. Even the Old Man Hiram Percy Maxim 1AW used 73s on his QSL cards.”
Well, even Hiram Percy Maxim has been incorrect and incorrectly used grammar. (chuckle)
There is something to be said about teaching new amateur radio operators the best of our traditions, history, skills, procedures, protocols, ethics, and culture. There’s no rational argument that can make a case that allowing these aspects of our service and hobby to degrade over time (by the lack of Elmering) is a good way to see our service and hobby thrive and progress.
I don’t see any slippage from high standards as being a good strategy for nurturing growth, progress, and effectiveness of our service and hobby. Keeping some level of excellence in every aspect of our hobby can only be beneficial.
In this case, how many new hams that learn to repeat ham lingo know anything of the history behind the common “73?” My dead horse turned glue is educational and it is my belief that educating about origins elevates the current.
73 – NW7US
..
Old, But Still Useful!
This old WWII military training video is still useful regarding Morse code:
[embedyt]https://www.youtube.com/watch?v=YqTn-165orw[/embedyt]
This is an antique United States Navy Training Film from 1943/1944, in which proper hand-sending of Morse code is demonstrated. The film covers some basic principles and mechanics of manual keying of the International Morse code, as used during WWII.
Amateur (Ham) radio operators find Morse code (and the ‘CW’ mode, or ‘Continuous Wave’ keying mode) very useful, even though Morse code is no longer required as part of the licensing process. Morse code is highly effective in weak-signal radio work. And, preppers love Morse code because it is the most efficient way to communicate when there is a major disaster that could wipe out the communications infrastructure.
While this military film is antique, the vintage information is timeless, as the material is applicable to Morse code, even today.
There’s more about Morse code, at my website: http://cw.hfradio.org
For additional joy, here are a few of old films regarding Morse code:
Morse Code – Principles and Basic Techniques (US Army Signal)
(Learn to Send Perfect Morse Code by Hand – Vintage Training Film (Ham Radio / CW))
[embedyt]https://www.youtube.com/watch?v=qmg1MlstxWM[/embedyt]
Vintage 1944 Radio Operator Training: How to Send Morse Code (CW) by Hand
[embedyt]https://www.youtube.com/watch?v=XjupJslRj5E[/embedyt]
This one is a pretty cool film:
1939 Film: New Zealand Shortwave Communications; Morse code (CW)
[embedyt]https://www.youtube.com/watch?v=H-KUat5WEkU[/embedyt]
I’ve also created a play list, and most of the videos are still online. Once and a while something changes and I have to update the list. Here is the list:
Original Title: TECHNIQUE OF HAND SENDING, by Department of Defense, Published 1944
Usage CC0 1.0 Universal
TECHNIQUE OF HAND SENDING
PIN 23735 1944
IMPORTANT PARTS OF THE TRANSMITTER, TENSION SPRING, ADJUSTING CONTACTS, ADJUSTING SPRINGS. ELEMENTS OF MORSE CODE, TIMING, AND PARTS OF BODY THAT FUNCTION WHEN TRANSMITTING CODE. IMPORTANCE OF CORRECT POSITION AND OPERATION.
Producer Department of Defense
Enjoy!