Posts Tagged ‘military’

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.

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.

Please subscribe to my YouTube Channel: https://YouTube.com/NW7US

Also, please click on the bell, to enable alerts so that when I post a new video, you will be notified. By subscribing and making sure that the bell (alert) notification is set to ALL, you will be kept in the loop for new videos and more.

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?
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

How I Reunited Two Devils Brigade Canadian and American Veterans of World War Two

In the 1990s while living in eastern Montana, I had the amazing experience of reuniting two soldiers that served in the Devil’s Brigade. They both trained near Helena, Montana.

One day, I was operating on the amateur radio shortwave Ten-Meter band, and a gentleman answered my, “CQ, CQ, CQ, this is N7PMS in Montana, Over”. I took notes of our conversation.

The next day, when again I called for any station to answer my call for a conversation, another fellow, from Canada, answered me. I learned something amazing: Both of these two men mentioned that, during World War Two, they both were in the same special forces unit, training near Helena, Montana.

One of these Veterans served in the Canadian Armed Forces, and the other in the American Armed Forces. Listen to my story, for the full details of this amazing experience I had as an amateur radio operator.

Jump to 3:22 if you wish to skip my introduction to the story, during which I give some background on when and so on:
https://youtu.be/YFMplHjxy6s?t=3m22s

This certainly was one of the most memorable moments in my amateur radio hobby experience! The joy of reuniting friends is good.

From https://en.wikipedia.org/wiki/First_Special_Service_Force:

The 1st Special Service Force (also called The Devil’s Brigade, The Black Devils, The Black Devils’ Brigade, and Freddie’s Freighters), was an elite American-Canadian commando unit in World War II, under command of the United States Fifth Army. The unit was organized in 1942 and trained at Fort William Henry Harrison near Helena, Montana in the United States. The Force served in the Aleutian Islands, and fought in Italy, and southern France before being disbanded in December 1944.

The modern American and Canadian special operations forces trace their heritage to this unit. In 2013, the United States Congress passed a bill to award the 1st Special Service Force the Congressional Gold Medal.

Thank you for watching, and sharing. Comments are welcome: do you have a memorable moment in your radio hobby experience on the air?

73 de NW7US

Hidden heroes

The BBC have just broadcast and put on YouTube an excellent hour long documentary about two people whose wartime work is credited with shortening the war and saving millions of lives. Yet because of the cold war and the climate of secrecy, credit came late or not at all.

Code-Breakers: Bletchley Park’s Lost Heroes‘ details the work of young mathematician Bill Tutte who broke the German’s top-secret Lorenz code and Post Office engineer Tommy Flowers who built the first electronic computer ever – to replace ‘Heath Robinson’, the mechanical device used to process the code-breaking.

Bill Tutte and Tommy Flowers were both ‘scholarship boys’ who benefitted from the best educational and research opportunities available to their generation. Earlier conflicts may not have been able to discover and develop such talents. (And it’s questionable whether comparable educational opportunity is available today.)

It’s hinted towards the end of the program that the extended secrecy about their achievements is connected to the assumption that the Soviets continued to use the captured German Lorenz system into the 1950s. You can only imagine Tommy Flowers’ frustration, biting his tongue every time someone referred to ENIAC as the first computer!

You have to marvel at the beautiful minds of these two men – dealing with complex matrices and patterns and the logic associated with understanding them – without the tools we take for granted today. One of my favourite scenes is Bill Tutte at his desk with a hand drawn grid on a large sheet of paper tracking the pattern of the characters in the coded messages.

The unfortunate & epic saga of the perfect military radio

The long awaited but ultimately unwanted GMR radio

As my day job starts to include more long term projects & project management I was particularly intrigued by an article in arstechnica.com. The article is, “How to blow $6 billion on a tech project“, although the title may be more inflammatory than technically accurate.

The article covers the 15 year development of an advanced & unified military radio communications system that suffered from multiple issues including scope-creep & a rapidly changing underlying technology.

If you are involved with a group that is working to develop a product or service you’ll really get something from this article. If you interested in radio systems, military or otherwise, you’ll find this interesting as well.

Its hard to image the frustration people suffer when contributing to a project that is mismanaged unless you have been there yourself. I hate to think of the wasted effort that resulted when people found out How to blow $6 billion on a tech project

Monitoring Odyssey Dawn

One of the most memorable DX programs was Radio Nederland’s Media Network presented by the energetic and innovative Jonathan Marks. Both the program and the presenter live on in different guises.

I remember being astounded to hear intercepted military signals from the early hours of the Falklands War being broadcast on the program. Long before crowdsourcing or the internet, Jonathan Marks had a network of highly skilled shortwave enthusiasts and gave them a destination – a tape recorder linked 24/7 to a phone number – where they could leave recordings they had made along with relevant details like time, frequency and identifying callsigns etc. From memory he had sounds of commands being issued by the Argentine Navy to the Belgrano.

After almost 20 years on air the last Media Network was broadcast in 2000. The program morphed into a weblog in the northern spring of 2003 as war broke out in Iraq.
I was reminded of Jonathan Marks’ ingenuity by reports this week of another radio enthusiast based in Holland and how his monitoring activities revealed a US Psyops broadcast as part of the current ‘Odyssey Dawn’ operation in Libya. It was heard on 6877kHz at 0900Z Sunday 20 March.

In fact Jonathan Marks may have been one of the sources of this latest story! It appeared on his Critical Distance blog the day before.

Now in place of Media Network’s phone and cassette recordings, we have blogs, twitter and audioboo! And a torrent of information.

The Milcom Monitoring Post blog is pulling material together including mp3 clips. But the action and spots are moving very fast. The most appropriate tools appears to be twitter feeds. The source of the psyops recording is @FMCNL. Other monitoring tweets come from @MilcomMP and @QSLRptMT, occasionally using hashtags such as #odysseydawn or #libya.

US Marines conduct air strikes in support of Operation Odyssey Dawn

An AV-8B Harrier jump jet returns to USS Kearsarge for fuel and ammunition resupply while conducting air strikes in support of Joint Task Force Odyssey Dawn, March 20, 2011. (USMC/Flickr)

@cencio4 David Cenciotti is an aviation writer and he’s published comprehensively detailed daily ‘debriefings’ of Operation Odyssey Dawn. His writing is clear and military acronyms are de-coded and explained.  The posts on his blog reveal an deeply informed understanding of strategy and a profound knowledge of the aviation industry. His analysis shows how even in the heat of battle there’s some high powered marketing going on!

Here are some of the frequencies that were being monitored in the early stages of the campaign:
4196.0 Naval Military style CWC tracking net USB (American English accents). AGI (3/21 @ 2150 UTC). Early on in Operation Odyssey Dawn that was used as a NATO AWACS tracking net USB: Callsign Magic ##/NATO ##
5725.0 UK Royal Navy CWC-style net USB.
6688.0 French Strategic Air Force Net – Commandement Des Forces Aériennes Stratégiques (CFAS) USB: Callsign Capitol
6712.0 French Air Force Commandement De La Force Aérienne De Projection (CFAP) USB: Callsign: Circus Verte
6733.0 RAF TASCOMM YL weather traffic to Solex 11 a Sentry AEW1 with TAF weather for LCRA RAF
Akrotiri. QSYed to 9019.0 and 9031.0 kHz USB
6761.0 USAF Global refueling Operations USB
6877.0 USAF Psyop transmissions against Libyan Navy + jamming
9019.0 UK RAF TASCOMM USB TAF weather traffic.
9031.0 UK RAF TASCOMM USB Operational Messages + TAF weather traffic
10315.0 DHN 66 NATO Geilenkirchen GER E-3 AWACS/Magic to DHN66 Link USB
12311.0 French Air Force Centre De Conduite Des Opérations Aériennes (CCOA) USB: Callsign Veilleur/AWACS callsign Cyrano.
16160.0 French Air Force up with voice and RATT on 16160 kHz USB.
Libyan GMMRA HF ALE network was still active as of 3/21/2011 on 5368.0 6884.0 8200.0 9375.0 10125.0 10404.0.

Seems like a good time to sign up for and account with www.globaltuners.com to get my radio ears a little closer to the action. If you follow any of the twitter accounts mentioned above you will have no shortage of up to the minute details of air (and radio) traffic to follow.


Subscribe FREE to AmateurRadio.com's
Amateur Radio Newsletter

 
We never share your e-mail address.


Do you like to write?
Interesting project to share?
Helpful tips and ideas for other hams?

Submit an article and we will review it for publication on AmateurRadio.com!

Have a ham radio product or service?
Consider advertising on our site.

Are you a reporter covering ham radio?
Find ham radio experts for your story.

How to Set Up a Ham Radio Blog
Get started in less than 15 minutes!


  • Matt W1MST, Managing Editor




Sign up for our free
Amateur Radio Newsletter

Enter your e-mail address: