Posts Tagged ‘communications’

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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Modern Amateur Radio Hobby – An Introduction

This video is an introduction to an international public-service and technology hobby known as ‘amateur radio’ (or ‘ham radio’).

[embedyt] https://www.youtube.com/watch?v=K40HpIjDLRs[/embedyt]

Amateur radio (also called ham radio) describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication. The term “amateur” is used to specify “a duly-authorized person interested in radioelectric practice with a purely personal aim and without pecuniary interest;” (either direct monetary or other similar rewards) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.).

The amateur radio service (amateur service and amateur-satellite service) is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual stations licenses with an identifying call sign. Prospective amateur operators are tested for their understanding of key concepts in electronics and the host government’s radio regulations. Radio amateurs use a variety of voice, text, image, and data communications modes and have access to frequency allocations throughout the RF spectrum to enable communication across a city, region, country, continent, the world, or even into space.

Amateur radio is officially represented and coordinated by the International Amateur Radio Union (IARU), which is organized in three regions and has as its members the national amateur radio societies which exist in most countries. According to an estimate made in 2011 by the American Radio Relay League, two million people throughout the world are regularly involved with amateur radio. About 830,000 amateur radio stations are located in IARU Region 2 (the Americas) followed by IARU Region 3 (South and East Asia and the Pacific Ocean) with about 750,000 stations. A significantly smaller number, about 400,000, are located in IARU Region 1 (Europe, Middle East, CIS, Africa).

Activities and practices

The expansive diversity found in the amateur radio hobby attracts practitioners who have a wide range of interests. Many hams begin with a fascination of radio communication and then combine other personal interests to make the pursuit of the hobby rewarding. Some of the focal areas amateurs pursue include radio contesting, radio propagation study, public service communication, technical experimentation, and computer networking. But, that is just a sampling of interest areas found in the hobby.

Amateur radio operators use various modes of transmission to communicate. The two most common modes for voice transmissions are frequency modulation (FM) and single sideband (SSB). The FM mode offers high-quality audio signals, while SSB is better at long distance communication when bandwidth is restricted.

Modern personal computers have encouraged the use of digital modes such as radioteletype (RTTY) which previously required cumbersome mechanical equipment. Hams led the development of packet radio in the 1970s, which has employed protocols such as AX.25 and TCP/IP. Specialized digital modes such as PSK31 allow real-time, low-power communications on the shortwave bands. More robust digital modes have been invented and improved, including such modes as Olivia, JT65, and WSPR.

NASA astronaut Col. Doug Wheelock, KF5BOC, Expedition 24 flight engineer, operates the NA1SS ham radio station in the Zvezda Service Module of the International Space Station. Equipment is a Kenwood TM-D700E transceiver.

Amateur radio operators, using battery- or generator-powered equipment, often provide essential communications services when regular channels are unavailable due to natural disasters or other disruptive events.

This video comes to us via Canada, and is used by permission from Bernard Bouchard – / ve2sms – The original video was published on Feb 28, 2013.- Website is https://www.ve2cwq.ca/amateur-radio-club-ve2cwq/

Voici maintenant, la version complète du documentaire «La radioamateur» d’une durée de 11 minutes. On y aborde toutes les activités sur le monde de la radioamateur. Ce vidéo a été produit par le Club Radioamateur VE2CWQ / Canwarn-Québec. Pour information: https://www.ve2cwq.ca/

Connect with me at https://NW7US.us

USA Amateur Radio information: http://ARRL.org

New Book: Learning, Living, and Loving Morse Code…

There is a new book from a fellow Morse code amateur radio operator, Chris Rutkowski (NW6V), about “Learning, Living, and Loving Morse Code (in a Digital World).” NICE!

Title: “The CW Way of Life
link: https://amzn.to/3Tm3KfD

I received a new book! Here it is, at my radio shack operations desk, at NW7US radio station.

Already, I think it rivals any other book on the topic, including “The Art and Skill of…,” or, “The Zen of…”

It is not, however, meant to replace, but to augment, what is available. But, it is a complete guide, including a “work book” section (nearly half of the book?) on how to improve your skill. Really good stuff, but I’m only in one day.


73 de NW7US dit dit
https://nw7us.us

..

Perfect Straight-Key Morse Code? Can It Be Made Without Machines?

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.
While this military film is antique, the vintage information is timeless, as the material is applicable to Morse code, even today.  This film has the answer to the question, “Can a person craft perfect Morse code by straight key, without the help of a computer or machine?
[embedyt] https://www.youtube.com/watch?v=qmg1MlstxWM[/embedyt]
The International Morse Code (sometimes referred to as CW in amateur radio jargon because a continuous wave is turned on and off with the long and short elements of the Morse code characters) is a type of character encoding that transmits telegraphic information using rhythm. Morse code uses a standardized sequence of short and long elements to represent the letters, numerals, punctuation and special characters of a given message. The short and long elements can be formed by sounds, marks, or pulses, in on off keying and are commonly known as dots and dashes or, dits and dahs. The speed of Morse code is measured in words per minute (WPM) or characters per minute, while fixed-length data forms of telecommunication transmission are usually measured in baud or bps.
Why is it called Morse code? This character encoding was devised by Samuel F. B. Morse, the creator of the electric telegraph. This Morse code came in two flavors, in the beginning years of its usage. One was in use by the railroads of America, and is known as American Morse Code. And, there is a unified, internationally-used version (adopted by radio operators), now known as the International Morse Code. Now, when most people refer to Morse code, or CW, they mean, International Morse Code.
Currently, the most popular use of Morse code is by amateur radio operators, although it is no longer a requirement for amateur licensing in many countries. In the professional field, pilots and air traffic controllers are usually familiar with Morse code and require a basic understanding. Navigational aids in the field of aviation, such as VORs and NDBs, constantly transmit their identity in Morse code.
Morse code is designed to be read by humans without a decoding device, making it useful for sending automated digital data in voice channels. For emergency signaling, Morse code can be sent by way of improvised sources that can be easily keyed on and off, making Morse code one of the most versatile methods of telecommunication in existence.
More about Morse code, at my website: http://cw.hfradio.org
73 de NW7US dit dit

Short Demonstration of Using Ham Radio Deluxe with WSJT-X and FT8 Digital Mode

Ham Radio Deluxe can log your WSJT-X FT8, JT65A, and JT9 QSOs, via the JT-Alert software. This is a demonstration of my use of HRD and Logbook, during an FT8 QSO,today.

As some of you know, I have had some differences of opinion regarding the selection of frequencies chosen by the FT8 creators and advocates. Regardless, I do still use the mode. Here is proof:

Go ahead and share, if you would. And, please subscribe to my YouTube channel, as I will be creating many how-to videos in the near future.

Thanks and 73 … de NW7US

On How NCIS Maligned the Amateur Radio Service

EDIT: Please view the NEW article, in which the FULL VERSION of this video exists.

I’ve been reading some of the chatter regarding the NCIS episode in which they incorrectly portray the amateur radio service. I thought I would make a video (vlog) and express my thoughts.

I use my new headset mic to make the video. If you have a few moments, please check it out, and let me know how the mic sounds.

Of course, share your thoughts on the NCIS thing… thanks!

https://www.youtube.com/watch?v=rv5TsoE0AZQ

Yes, the video gets prematurely cut off.  The editing software on my cell phone chopped off the ending, and I did not realize it until after it posted the video.  I’ll record a follow-up video that includes the ending thoughts, but in a new vlog edition.

Cheers and 73 de 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:

CW Play 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!


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