Commemorating 80 years 

An important stage in the liberation of Western Europe

Operation Market Garden was an Allied military operation during the Second World War fought in the German-occupied Netherlands from 17 to 25 September 1944. Its objective was to create a 103 km salient into German territory with a bridgehead over the Nederrijn (Lower Rhine River), creating an Allied invasion route into northern Germany. This was to be achieved by two sub-operations: seizing nine bridges with combined US and British airborne forces (´Market´) followed by British land forces swiftly following over the bridges (´Garden´).

The airborne operation was undertaken by the First Allied Airborne Army with the land operation by XXX Corps of the British Second Army. The airborne soldiers, numbering more than 41,000, were dropped at sites where they could capture key bridges and hold the terrain until the land forces arrived. The land forces consisted of ten armoured and motorised brigades with a similar number of soldiers. The land forces advanced from the south along a single road surrounded by flood plain on both sides. The plan anticipated that they would cover the 103 km from their start to the bridge across the Rhine in 48 hours. About 100,000 German soldiers were in the vicinity to oppose the allied offensive. It was the largest airborne operation of the war up to that point (Wikipedia ©). Perhaps the most famous, after D-Day, in the history of the Second World War.

As part of Operation Market Garden paratroopers of the Allied forces, such as American, British, Canadian, Polish and Dutch troops, landed in the Nijmegen region on 17 September 1944. The region became a battlefield during Operation Market Garden and most of the inhabitants took refuge in the woods or neighbouring towns. It took more than a week of heavy fighting before parts of the region were temporarily liberated. Many people and military were killed and buildings and bridges were destroyed. At the cost of many young soldiers the important Waal-bridge in Nijmegen was conquered. In our collective mind the entire region was completely liberated in 1944, but this was only for a period of three weeks. There was still hard fighting during the winter and complete liberation was not achieved until may 1945.

YouTube video: Operation Market Garden

The special event

From September 13 to 19 a special event station will be operating in the Nijmegen region of the Netherlands commemorating 8Ø years of freedom. The callsign is PA8ØOMG.

During 7 days they will activate the callsign PA8ØOMG and work amateur radio operators across the world. If you find yourself in the vicinity of Groesbeek and Nijmegen, be sure to visit us throughout the activities of the special event station. We are situated at one of the exact landing grounds of the 82nd Airborne division in 1944. Our website https://radioclublimburg.nl/pa80omg/index.html

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This livestream recording is from September 1, 2024 – the NW7US Radio Communications Channel Livestream.  We do this livestream every Sunday at 21:15 UTC.  Here is the link to the livestream from this past Sunday:

The livestream list is here:

https://www.youtube.com/@nw7us/streams

I hope to see you in our livestream live chat, during the next session on Sunday, at 21:15 UTC.  See you there!

We're back!

Read in over 150 countries, we bring you 125+ pages of Amateur Radio content from the Southwest corner of Canada and elsewhere. With less fluff and ads than other Amateur Radio publications, you will find Amateur Radio related articles, projects, profiles, news, tips and how-to's for all levels of the hobby.

You can view or download it as a .PDF file:  

Previous Communicator issues:

Search for past Communicator issues

and a full index is HERE.  

As always, thank you to our contributors, and your feedback is always welcome. 

The deadline for the next edition is October 15th and we're especially looking for articles and stories about 3D printing for amateur radio.

If you have news or events from your club or photos, stories, projects or other items of interest from BC or elsewhere, please contact us at [email protected]

73,

John VE7TI
'The Communicator' Editor

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.

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Hello summer...

With another big Summer issue. The July-August 2024 Communicator, digital periodical of Surrey Amateur Radio Communications is now available for viewing or download.

Read in over 150 countries, we bring you 120+ pages of Amateur Radio content from the Southwest corner of Canada and elsewhere. With less fluff and ads than other Amateur Radio publications, you will find Amateur Radio related articles, projects, profiles, news, tips and how-to's for all levels of the hobby.

You can view or download it as a .PDF file:  

Previous Communicator issues:

Search for past Communicator issues

and a full index is HERE.  

As always, thank you to our contributors, and your feedback is always welcome. 

The deadline for the next edition is August 15th.

If you have news or events from your club or photos, stories, projects or other items of interest from BC or elsewhere, please contact us at [email protected]

73,

John VE7TI
'The Communicator' Editor

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.

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.