Posts Tagged ‘history’

Handie-Talkie or Walkie-Talkie?

The Motorola HT-220 Handie-Talkie

In ham radio, we often use Handie-Talkie or HT to describe a compact, handheld transceiver. My first exposure to the term Handie-Talkie was when I first became a licensed radio amateur in 1977. While I was a student at Purdue University (W9YB), the absolute coolest VHF radio to have was the Motorola HT-220. Even a used one commanded a high price so they were out of my price range and I never owned one. These were 6-channel crystal-controlled transceivers…back then you had to set up the radio with the particular 2m frequencies you wanted to use. Because it was such an iconic radio, there are many HT-220 enthusiasts still around with websites with tons of useful information. See the HT-220 Page.

Motorola trademarked the name Handie-Talkie and used that nomenclature for many years with its line of portable radios. However, this trademark has expired, so now Handie-Talkie is a generic term.

The First Handie-Talkie

But the HT-220 was not the first Handie-Talkie, so I started poking around to find out how this name originated. Back in World War II, the SCR-536 was a portable “hand-held” transceiver developed in 1940 by Galvin Manufacturing (later Motorola, Inc.)  I put “hand-held” in quotes because, by today’s standards, it was a Hand FULL. But most people consider the SCR-536 to be the first modern, self-contained HT transceivers. The Wikipedia article for the SCR-536 describes the radio quite well. The radio put out about 360 mW of RF power on 3.5 and 6.0 MHz (Oops, I mean 3500 to 6000 kilocycles) using Amplitude Modulation (AM). The circuitry relied on smallish vacuum tubes, creating quite a design challenge. Motorola has a page on its website that talks about the origins of the radio. IEEE Spectrum also published an excellent article: The SCR-536 Handie-Talkie Was the Modern Walkie-Talkie’s Finicky Ancestor. The January 2005 issue of QST has an interesting article by Gil McElroy, VE3PKD, A Short History of the Handheld Transceiver. It provides more history and insight to this fun topic.

The SCR-536 Handie-Talkie

 

 

 

 

 

 

 

 

 

The First Walkie-Talkie

A few years later (1942), a backpack portable radio was introduced, called the SCR-300. I always assumed that the backpack-style radio would have come first and the more compact radio SCR-536 would be later. (Actually, there were previous backpack radios, such as the SCR-194). This new backpack-style radio was referred to as a Walkie-Talkie. According to the manual, the SCR-300 was “primarily intended as a walkie-talkie for foot combat troops”. I suppose the emphasis was on how you can walk and talk, with a radio on your back.

The SCR-300 Walkie-Talkie transceiver.

This article: SCR-300 WW2 Radio Backpack: The “Walkie Talkie” That Shaped the War describes this radio as a game-changer for frontline troops. The radio weighed a heavy 35 pounds, and used Frequency Modulation (FM) on 40 to 48 Megacycles.

Of course, with technology development, there is always the question of “who was first”? The SCR-194 that predated the SCR-300 might be considered the first walkie-talkie. However, the SCR-300 and the SCR-536 seem to get all of the glory, probably due to their impact on the war effort. However, take a look here if you want to dig deeper: TALK the WALK or WALK the TALK: Who actually developed the first Walkie-Talkie?

This article describes the development and use of the SCR-300 and mentions some of the limitations of the SCR-194: SCR-300 History Development Employment and Details Final Draft This is a big file with many photos but worth reading if you have the time.

Today’s Terminology

The Yaesu FT-4X handheld transceiver

Fast forward to today and we see that the HT and Handie-Talkie nomenclature is common in the amateur radio world. The photo to the left shows a modern 2m/70cm HT, the Yaesu FT-4X.

The term “walkie-talkie” has morphed to something quite different and is used generically to describe a handheld radio. This term covers a wide range of radios, from low-cost Family Radio Service (FRS) radios to higher-quality professional radios. This is quite different from the original Walkie-Talkie, a backpack radio weighing 35 pounds.

The military has progressed with improved communication technology, still using backpack-style radios, now referred to as manpack radios. These are amazing radios that pack extensive capability into a relatively small package. The AN/PR-158 shown below covers 30 to 2500 MHz in frequency, satellite comms, advanced encryption, narrowband and wideband modes: AM, ASK, FM, FSK, PSK, CPM, GMSK, and plenty more. This radio weighs 12.7 pounds with the battery installed, so a lot lighter than the old SCR-300.

A modern military manpack radio (AN/PR-158)

So that’s a quick tour through some radio terminology along with a bit of historical perspective. I discovered there is an infinite supply of information out there on the history and technology of military radios. If you want to dig deeper, go for it!

73 Bob K0NR

The post Handie-Talkie or Walkie-Talkie? appeared first on The KØNR Radio Site.

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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More about the original W2LJ

This is going to be a long post. In our last episode, I was telling you all about the musings and thoughts I have had about the original W2LJ ...... who he was and what he was like.  The experience I have had over the past couple of days has just been amazing and more than I could ever have hoped for.

In my Google search, I had mentioned that Ed and Norma had a daughter. I also saw in the Google results that his daughter has a Facebook page. Not totally sure that I would be addressing the right person, I decided to send a Facebook message, anyway. I introduced myself and explained why I was contacting her. After all, I didn't want her to think that some creepy stranger from out of left field was contacting her for nefarious reasons. Lord, knows, we have enough of that, these days. Between scams, phishing and other evil intentions, I wanted his daughter to know this was harmless.

I didn't know what to expect, or even if I would ever get a reply. What happened next was one of the most gracious and kind exchanges from Carmen, Ted's (as he preferred to be known) daughter, and his grandson, Jon. Two of the most remarkable people who I am so glad to know, and will be eternally grateful to.

Carmen answered me via e-mail. (I have their permission to post - I would never do that without their consent):

Hi!

Yes, I am the daughter (and only child) of Edward (Ted) Roscoe Swoffer who was a ham radio operator since adolescence.  He was born and brought up in Walnut Grove, Minnesota one of eight children. He signed up for duty in World War !! And served on submarine duty (Peto and the Albacore).  The Albacore was torpedoed shortly after he got off to marry my mom.  He studied Electrical Engineering at Penn State and worked for Singer Link in Binghamton for many years.  He and my mom (Norma) were amazing grandparents to my three children and I am so grateful.

My father was very quiet and humble, never boasting of his many accomplishments.   He was not very social, although well liked by all.  I am not sure what all those letters mean concerning his equipment etc.   I do have many of his postcards from far and near and would be glad to send you one.  Let me know if you have further questions and let me know your address if you want one of his postcards from other ham operators.  I donated a Morse Code machine and some other stuff to a local museum called Tech Works.

I look forward to your response!

Carmen

Wow! I was floored! I was hoping for some kind of response and was so glad to receive such a warm and welcoming one!

I had cross posted to the AmateurRadio.com site hoping that other folks who might have known Ted would offer some tid bits about him. His grandson Jon replied there:

Hi Larry – Thanks so much for your post and your curiosity. Ted Swoffer (“Pappy” to his grandkids) was my grandfather. He was a great one. So much I could share with you about him. He started building radios as a kid in Walnut Grove, Minnesota, had multiple tours of duty in the pacific theater in WWII as a radio/sonar guy aboard two USN submarines (USS Albacore and USS Peto), and after the war graduated from Penn State with an engineering degree. Joined Singer Link in Binghamton, NY as an aeronautical engineer, working on flight simulators for several warbirds. While I spent much of my childhood being fascinated with his many hobbies, he was a quiet man. And amateur radio remained something that he did by himself. Perhaps that’s why nobody else in the family continued the craft. I think he would be so pleased to know that his call sign lives on through you.

And Jon also sent me an e-mail:

Hi Larry - attached is a wartime photo of Ted Swoffer.  Also attached is a picture of a collage of post cards to W2LJ from all over the world that I made a few years ago.  

I’ll look through other things to see if I have any other W2LJ stuff I could send you

And also from Jon:

Larry - thanks for sharing!  Very cool to see the W2LJ license plate.  

Ted was a Morse coder like you.  You two would have had a lot in common. 

And here's the photos that both Carmen and Jon sent.

 




Ted, the original W2LJ was an amazing man! And to borrow a radio term, I found some resonance between him and my own Dad. Both faithfully and bravely served in the Armed Forces during WWII. While Ted was a Navy sonarman, my Dad's first assignment with the Signal Corp was a detachment to the joint British/American team that was developing enhancements to radar. Unlike Ted, my Dad never went on to getting an Amateur Radio license. Perhaps that skipped a generation and was my destiny.

Carmen also informed me that her Dad was a CW man. Yay! I was elated to find that out. It makes me feel like i'm somehow carrying on his legacy, even though I never knew him. I did mention to Carmen and Jon that I wished I had known Ted back in 1978 when I was studying for my own Novice license and beyond. I know in my heart of hearts he would have been a fantastic Elmer, and boy, I could have used one back then.

As I said before, this was an amazing experience. I got to double dip! Not only did I learn so much more about this amazing man who originally held the callsign W2LJ, but I was also able to meet and converse with his daughhter and grandson - two of the most kind, warm, and friendly people you'd ever want to know. Thanks so much, Carmen and Jon! I can only hope that my Amateur Radio career would make Ted proud that W2LJ lives on.

72 de Larry W2LJ
QRP - When you care to send the very least!

Musing

I often wonder about Edward Swoffer. He was the original W2LJ before I took on the call sign. Ed lived in Binghamton, NY and other than that, I know not much about him.

Was he an SSB guy? Was he a CW devotee like I am? Was he into DX? Traffic Handling? Or maybe he was just an inveterate rag chewer? By some oddball chance, could he have been a QRPer? What clubs, if any, did he belong to? Did he participate in Field Day with his Ham buddies? What kind of station did he have? What was his antenna farm like? A search on Google maps shows their address (which is public info) has a decent sized back yard with lots of trees. I'm betting he was a wire antenna guy.

He was an Amateur Extra, so I have to believe that, at least for a while, he was more than just a casual operator. 

Doing a Google search on W2LJ doesn't lead to anything other than stuff about me. By doing some digging on the name Edward Swoffer AND Binghamton, NY I was able to find out that Ed was born in 1919 and died in 1993. That makes him two years older than my Dad.  He was married to Norma Thompson who passed away in October 2009, They had a daughter who earned a degree in Philosophy. Other than that, zip.

Why the fascination? No reason, really. It's just that it would be neat to sit down and talk with him and find out if we have anything else in common besides being W2LJ. Or, for that matter, a family member who could tell me more about him.

What would be the icing on the cake would be to somehow acquire one of his QSL cards. THAT would be a treasure!

History was my favorite subject in school. As a kid, I loved reading biographies and still do. I have an appreciation for things from the past. It would be fun to know more about the original W2LJ.

72 de Larry (the current W2LJ)

QRP - When you care to send the very least!

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.

International Morse Code Day (April 27)

Morse Code Day on April 27 (every year) honors one of the inventers of the Morse code, Samuel Morse, who was born on this day in 1791.

Morse Code Day on April 27 (every year) honors one of the inventers of the Morse code, Samuel Morse, who was born on this day in 1791.

Happy Morse Code Day, April 27 (every year).

Samuel Finley Breese Morse (April 27, 1791 – April 2, 1872) was an American inventor and painter. After having established his reputation as a portrait painter, in his middle age Morse contributed to the invention of a single-wire telegraph system based on European telegraphs. He was a co-developer of Morse code and helped to develop the commercial use of telegraphy.

Alfred Vail developed the dot-dash structure, and Leonard Gale along with Vail was instrumental in developing the mechanical receiving apparatus for code.

Samuel Morse gets most of the credit because of his work in promoting this code as a viable means of communication. Morse code is still used now. Amateur radio is one of the communities in which Morse code is popular and in daily use.

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

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